- Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] Cross-section question
by Tom Goddard 18 Oct '13

18 Oct '13

Hi Lawrence, Sure it is easy to see plane 72. Use the Volume Viewer dialog, show the planes panel (menu Features / Planes), press the "One" plane button in that panel and set the plane number entry field to 72. To assure you see the full resolution data make sure "Step" is set to 1 above the volume dialog density map histogram, and that "depth" is set to 1 in the Planes panel. This and other Chimera density map features are described in the Chimera guide to volume data display http://www.cgl.ucsf.edu/chimera/data/tutorials/volumetour/volumetour.html Tom On Oct 18, 2013, at 10:09 AM, "Tartaglia,Lawrence J" wrote: > Hi Tom, > > Thank you for getting back to me. I should have been a bit more clear. What I want is the exact "central" section. I'm not sure if you are familiar with cryo-electron microscopy? I used a box size of 143 pixels to box my virus particles. What I would like to see if image 72 (central section) of my reconstruction. Is there a way to do that? I've attached an image of an example central section (left hand side) using the program IMOD. I'm sorry for the confusion... > > Best, > > Lawrence > > > On Thu, 17 Oct 2013 09:43:43 -0700, Tom Goddard wrote: >> Hi Lawrence, >> >> I'm not sure what you mean by "exact cross-section". Do you mean >> aligned to the virus map grid axes? If so the Orient button at the >> bottom of the volume viewer dialog will do that. But probably it is >> better to simply specify which planes to show using the Region Bounds >> panel of the volume viewer dialog (Features menu) - specify a z range >> 120 125 1 to show planes 120 to 125 using step 1 (i.e. every plane). >> This will be better than using clip planes. >> >> Tom >> >> >> On Oct 16, 2013, at 11:35 AM, "Tartaglia,Lawrence J" wrote: >> >>> Hello, >>> >>> I have a cryoEM map of a virus that I'm visualizing in chimera. I'd like to get a perfect cross-section of the map that I can use for publication. I've used the "side view" tool, but I can't get an exact cross-section. Are there any options to achieve this? >>> >>> Thanks! >>> >>> Best, >>> >>> Lawrence >>> -- >>> Lawrence J. Tartaglia, Ph.D. >>> Postdoctoral Scientist >>> Agbandje-McKenna Lab >>> Department of Biochemistry and Molecular Biology >>> College of Medicine, University of Florida >>> _______________________________________________ >>> Chimera-users mailing list >>> Chimera-users(a)cgl.ucsf.edu >>> http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >>> > > -- > Lawrence J. Tartaglia, Ph.D. > Postdoctoral Scientist > Agbandje-McKenna Lab > Department of Biochemistry and Molecular Biology > College of Medicine, University of Florida<Screenshot-1.png>

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Cross-section question
by Tartaglia,Lawrence J 17 Oct '13

17 Oct '13

Hello, I have a cryoEM map of a virus that I'm visualizing in chimera. I'd like to get a perfect cross-section of the map that I can use for publication. I've used the "side view" tool, but I can't get an exact cross-section. Are there any options to achieve this? Thanks! Best, Lawrence -- Lawrence J. Tartaglia, Ph.D. Postdoctoral Scientist Agbandje-McKenna Lab Department of Biochemistry and Molecular Biology College of Medicine, University of Florida

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Normal to the plane of the aromatic ring at the centroid
by Pande, Ajay K 16 Oct '13

16 Oct '13

How would I draw a normal to the plane of an aromatic ring, at its centroid? Thanks Ajay Pande

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(no subject)
by edward el chamy 15 Oct '13

15 Oct '13

Hey i am a student using chimera 1.8 i have a question: how we find on a specific chain the different interaction domains? Thanks a lot

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Fwd: setting or hardware problem?
by Chao Wang 14 Oct '13

14 Oct '13

Hi, chimera users I am starting to use ucsf chimera to analysis protein structure recently. It is an excellent software, and I have no problem using it at school. But when I try to use it on my other pc at home. It doesn't work properly. The ribbon looks flat and dull, not a 3D looking anymore, like the situation showed in pic1 and pic2. My hardwares: School PC: win7 64 bit,cpu E5-1606, Nvidia Quadro 5000, 4G Home PC: win7 64 bit, cpu i5-2500k, AMD Radeon HD6700, 8G I know the video card of school's pc is much better, but I checked the hardware list. HD6700 is also compatible. Can anyone tell me what is wrong? I really appreciate it. [image: Inline image 1] [image: Inline image 1] Jack Wang

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Chimera commands to record MD movies
by psu4＠uic.edu 11 Oct '13

11 Oct '13

Dear Chimera, Since we run a lot of Amber MD simulation in remote clusters, we wonder if there is any Chimera command that can record the Amber MD trajectories remotely and save them as avi (or any other movie file formats)? If this is feasible, then we don't have to download all the trajectories to local and make the trajectory movies manually. We have searched the Chimera user manual but didn't see any command. If there are related commands which we didn't see, please forgive us : ) Thanks. * There is a way to activate X11 forwarding and use remote Chimera GUI to do this, but it's extremely slow and prone to freeze the computer. Cheers, Henry

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font size in pull-down menus
by Boaz Shaanan 09 Oct '13

09 Oct '13

Hi, Is there a way to change the font size of the pull-down menus? For some reason on the Windows (XP) v.1.5.1 they seem smaller to me. Nothing in terms of graphics (or my eyesight) has changed since I upgraded to 1.5.1 recently. Thanks, Boaz Thanks, Boaz Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Phone: 972-8-647-2220 ; Fax: 646-1710 Skype: boaz.shaanan‎

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Packaging sessions
by Amedee des Georges 08 Oct '13

08 Oct '13

Dear Chimera, Currently, Session saves don't save volume data, only link to them, which is an issue whenever one of those links is broken or when one wants to send a whole session to someone else. Would it be possible to have an additional saving option that could be called "Package session" (like in InDesign), where a folder is created and all the files associated to the session saved in it. This way, people could zip and send the package by email, or package their important sessions to make sure not to lose them, or just to move them around. By advance, many thanks, Amedee -- Amedee des Georges Frank lab Howard Hughes Medical Institute Dept. of Biochemistry and Molecular Biophysics 650 W 168th St, P&S Black Building room 221 New York, NY 10032 (T) 212 305-9527 (F) 212 305-9500 (E) ad2720(a)columbia.edu http://franklab.cpmc.columbia.edu

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want to converge 20 pdb files of a trimer
by ashok rout 07 Oct '13

07 Oct '13

Hi, I have a nmr structure of a protein which is a trimer. I want to converge 20 pdb files of the trimer, by Chimera. And also want to converge a specific region of the 20 pdb files of the trimer. Can you please assist me how to do this?? Thanks, Ashok -- thanks & regards, Ashok

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Structural Allignment in Chimera
by Syeda Hira Batool 06 Oct '13

06 Oct '13

Hello I want to know how chimera does Structural allignment. I am writing a python script to allign protein structures(from MD simulations) and eventually calculate RMSD. Please can anyone provide me a source code or a helping material.Thanx in advance. Hira Batool Student of BS-Bioinformatics Biosciences Department COMSATS Institute of Information Technology Islamabad, PAKISTAN

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info pivotting on a single atom
by Christian Martinoli 04 Oct '13

04 Oct '13

dear all, I have troubles in setting the center of rotation on a single atom of my model. i'm working with the command line to build up a short clip at the end.what i would need is pivotting the whole model on the three axes, rather than in 2D as seems work with cofr command. any help? Thanks in advance Christian -- Christian Martinoli University Of Pavia Dept. of Biology and Biotechnology "Lazzaro Spallanzani" Structural Biology Lab. Via Ferrata 1, 27100 Pavia Italy

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command line to define a plane
by Jean Didier Pie Marechal 03 Oct '13

03 Oct '13

Dear all, is there a way to define a plane from the command line. Something that would work providing a list of atoms or a selection. Cheers, JD Dr. Jean-Didier Maréchal Associate Professor The Computational Biotechnological Chemistry Team Unitat de Química Física Departament de Química Universitat Autònoma de Barcelona Edifici C.n. 08193 Cerdanyola (Barcelona) Tel: +34.935814936 e-mail: JeanDidier.Marechal(a)uab.es www: http://asklipio.qf.uab.es

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Re: [Chimera-users] Question about multi align viewer
by Elaine Meng 03 Oct '13

03 Oct '13

On Sep 20, 2013, at 9:33 AM, Sean Connell wrote: > Hello I was wondering if it is possible to calculate conservation statistics using only subsets of the aligned sequence. The reason I ask is that in my alignment I have differently families of proteins that have slightly different functions and I would like to highlight residues that are conserved in one subset but not in the other? > Hi Sean, Not directly. I believe you would have to create alignments of just those subsets. You could do that with some other program (including text-editor) before opening the alignment in Chimera, or you could do it in Chimera. Of course, keep the original file with the full alignment too! To edit in Chimera, open the full alignment and then from the sequence window menu choose "Edit... Delete Sequences/Gaps" and in the resulting dialog, choose which sequences to delete. <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/f…> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> You can then continue working with the subset alignment in Chimera, including saving it to a new file (sequence window menu "File... Save As"). I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco P.S. your original message was in an attachment, which was kind of weird, but I could view it by just clicking the attachment

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Stereoscope viewing
by Thompson, Matthew K 02 Oct '13

02 Oct '13

Can anyone recommend the best camera settings for stereoscope glasses? Mine just don't seem to turn out right.

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electrostatic surface calculation
by Ursula Schulze-Gahmen 02 Oct '13

02 Oct '13

I calculated the coulombic surface and the electrostatic surface for my molecule. They show a significant difference in the shape of a small surface area. For the electrostatic surface, I converted the pdb file into a pqr file using the pdb2pqr called from chimera. Then I ran APBS also from within Chimera. When I display this surface it exhibits a strong protrusion in an area where there is no side chain. This protrusion is not present in the Coulombic surface. Any idea where this is coming from? Thanks Ursula -- Ursula Schulze-Gahmen, Ph.D. Assistant Researcher UC Berkeley, QB3 356 Stanley Hall #3220 Berkeley, CA 94720-3220

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how to write script that can run chemera command
by 张海平 30 Sep '13

30 Sep '13

Dear professor: I find a command "delete ligand" can delete ligand from a protein. Then I have thousands of protein contain ligands, how can I write a script to do this command automotically, Thanks for your kindly help. Best regard Haiping Zhang

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Editing Question
by Kirk Moldoff 30 Sep '13

30 Sep '13

Hi, I'm working with a pdb model 3ALQ. It is a Tumor Necrosis Factor and its TNFR receptor. I'd like to be able to turn off the bound TNF. Or select it for deletion. Can't figure how to do this. Any suggestions? Ultimately I'd like to be able to save just the TNFR as a .pdb file. Thanks, Kirk -------- Kirk Moldoff www.galeriekirk.com 609-252-9479

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Generating a PDB file
by Nathalia Varejão 27 Sep '13

27 Sep '13

To whom it may concern, I'm using the chimera to visualize a protein ligand docking, but I want to save the best model as a PDB file that I can use anywhere to perform other analysis, is it possible? For example, the pdb that I saved by the chimera do not open in PyMol viewer... Can you help me? Nathalia

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STL file questions
by David Gene Morgan 26 Sep '13

26 Sep '13

Hi, I have a couple of questions about the chimera STL files. I tried to open one using chimera to determine whether they contain any color information, but I wasn't able to open the file I just wrote. I don't care about that, but I would like to know if they contain color information. Is there any way to control the degree of tesselation when writing an STL file? In other words, some STL files are huge because they contain huge numbers of triangles (and some 3d printers can't handle overly large files). I am wondering whether it is possible to control the size of the output files, which is effectively asking if it is possible to control the number of triangles in the file, how finely sampled the model is, etc. (however one wants to describe that property). Finally, as I understand STL files, they are usually "unscaled" (i.e., the co-ordinate system describing the vertices of the triangles doesn't have fixed length units). Is that true for the STL files chimera creates? If I wanted to create two models with an accurate reflection of their relative atomic sizes, are there tricks I will need to employ? -- David Gene Morgan Electron Microscopy Center 320C Simon Hall IU Bloomington 812 856 1457 (office) 812 856 3221 (3200) http://bio.indiana.edu/~cryo

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Calculating SAS areas for selected residues for a whole trajectory of structures
by Harald Lanig 24 Sep '13

24 Sep '13

Dear Chimera users, I am currently using chimera to calculate the solvent accessible surface for several selected residues of a single structure (I am using the Attribute calculator with the formula sum(atom.areaSAS) to do this). Is there a way to apply this to a set of structures coming from a molecular dynamics trajectory? I am interested in how the solvent accessible surface of a set of residues changes during the simulation. Any hint is highly appreciated! Best wishes, -Harald -- ------------------------------------------------------------------------ PD Dr. Harald Lanig Universitaet Erlangen/Nuernberg Computer-Chemie-Centrum Naegelsbachstr. 25, D-91052 Erlangen Phone +49(0)9131-85 26525 harald DOT lanig AT fau.de Fax +49(0)9131-85 26565 http://www.chemie.uni-erlangen.de/lanig ------------------------------------------------------------------------

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Building DNA along A PBD Using RNA command
by Joshua Carter 23 Sep '13

23 Sep '13

Hi, I'm working on a project in chimera that involves modeling the binding of a RNA-guided protein complex to a double stranded piece of DNA. What I need to do is be able to is either match a DNA pdb to the existing RNA pdb I have or build one using the rna command in chimera. I know there is a path command, is there any way I could specify that to build along a pdb I have already? Or am I just barking up the wrong tree entirely? Thanks,Josh

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Question about multi align viewer
by Sean Connell 20 Sep '13

20 Sep '13

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selecting a specific residue
by Elaine Meng 19 Sep '13

19 Sep '13

On Sep 18, 2013, at 8:53 PM, Serina Doolittle <serinadoolittle(a)me.com> wrote: > Hi again, > > So now i have another question... > I have selected the ligand because that is what my research mentor and I are interested in (the active site and ligand binding etc.) however, when i select "ligand" it also high lights other molecules around the protein, more around the surface, like butanol - how can i just select the ligand NADPH and not have to select the other small molecule ligands that are not part of the active site of the protein? can i do that? > > Serina Doolittle > Thanks! > Hi Serina, The "ligand" detection uses automatic rules and won't always get what you expect, but there are many other ways to select a specific residue. For example, you can select by residue name and/or number, or with the mouse in the Chimera window. With mouse: Ctrl-click on some atom selects it, and then keyboard up arrow will promote the selection to the whole residue. With command: specify residue name or number, e.g. select :nad select :254.a … would select residue named NAD, or residue 254 in chain A respectively. How do you find out the residue name or number? One way is by hovering the mouse over some atom or bond in the residue, which will pop up a balloon that shows atom name, residue name, and residue number. With menu: Select… Residue… allows selecting by name (all the residue names present will be listed in the menu). NADPH might have residue name NAP, NAD or something like that, since PDB files have 3-letter residue names. That would select all residues of that type, so you'd probably want to use one of the other methods if there are multiple NADPH molecules and you only wanted to select a particular one. Manual pages on selection and command-line atom specification: <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/selection.html> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/frameatom_spec.html> Also, you may want to look through the "getting started" tutorial to become more familiar with Chimera. <http://www.rbvi.ucsf.edu/Outreach/Tutorials/GettingStarted.html> I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco

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Hello
by A Amiri 19 Sep '13

19 Sep '13

Hello. I have a problem with chimera! i want to join two pdb file together by C-N peptide bond. Actually this is a modeling of a fusion protein that one part of its, is a protein and another part is a linker. I need a complete structure. I select the carbon atom from one model and nitrogen atom from another model. I use the "build structure<join modesl" menu for this purpose but the "apply" button is inactive still and i don't know how i can activate it! please help me. ________________________________

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Re: [Chimera-users] vop cover
by Elaine Meng 18 Sep '13

18 Sep '13

Hi Pradeep, That message is saying you must specify the density map. I.e. if the atomic structure is model #0 and the density map is model #1, the command could be something like vop cover #1 atom #0 Command usage and options: <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/vop.html#cover> Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco P.S. it is recommended you send Chimera questions to chimera-users(a)cgl.ucsf.edu instead of to me directly - thanks! On Sep 18, 2013, at 2:02 PM, Pradeep Pallan wrote: > Hi Elaine, > > I was looking at using vop cover. I have a case where part of the molecule > is not within electron density box. The map cuts off at the unit cell dimensions, > and my space group is P1. Where I need edensity is approximately at y= -10. > When I try the command > 'vop cover "atom"', it gives the message "file.pdb is not a volume". > > Is this the right way of getting the molecule covered in e density or do I need > to use a different option. > > Thank you, > PP

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Problem Using Transparency Command in Chimera
by Joshua Carter 18 Sep '13

18 Sep '13

Hi, My name is Josh Carter and I am an undergraduate researcher working at Montana State University. I am using chimera to make a movie a a protein complex interaction and I'm having trouble with the transparency command. When I type in just the command into chimera it doesn't even recognize it as a command. surftransp works but transp or transparency aren't recognized. Is there a bug fix I can run for this? Thanks,Josh

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How to determine the distance from SG of Cys to the centroid of a nearby Trp ring
by Pande, Ajay K 17 Sep '13

17 Sep '13

I am using Tools/Structure Analysis/Axes -Planes-Centroids. Selecting the Trp Indole ring, obtaining the centroid. Then selecting SG of Cys and the centroid and drawing an axis. That axis does not seem to pass (exactly) through the SG and Centroid- that' my first problem, the 2nd problem is to get the distance between the centroid and SG.

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colour by attributes is only colouring one chain of the dimer, how to make the colouring apply to both chains of homodimer
by Anne-Frances Miller 17 Sep '13

17 Sep '13

Dear team Chimers 1- Thank you for GREAT software ! 2- How to make the colouring apply to both chains of homodimer ? I have a homodimer in which features of the active site derive from both monomers so the degree of active site conservation will only show up if I can apply colour by attributes to both monomers (attribute will be conservation) Right now, colour by attributes is only colouring one chain of the dimer, chain A. Anne-Frances Anne-Frances Miller Professor of Chemistry Director, Magnetic Resonance Centre University of Kentucky Dept. Chemistry, 505 Rose Street Lexington KY 40506-0055

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Chimera Questions
by Serina Doolittle 16 Sep '13

16 Sep '13

Hi, My name is Serina Doolittle. I am an undergraduate research student at Armstrong Atlantic State University in Savannah, Ga. I am currently using Chimera to build two protein models. I have the proteins in the form that I want them in to 3D print. However, one of them is not a single chain protein. It has chain A and B. I hid chain B and focused on chain A because of the simplicity for the 3D protein model that I want. However, when you hide chain B and you put chain A on "show surface" that are like little holes or blotches missing from the protein where chain B is suppose to be. Is there anyway that I can fix this problem and single out chain A to make it look like it is completely lone in the "show surface" view. If you would like I will send you the Chimera file ("session"). That way you can visualize what I am trying to do. Serina Doolittle serinadoolittle(a)me.com 912-665-3259 Armstrong Atlantic State University Student

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How to move a domain in mouse mode /move selection
by Juergen Joachim Mueller 12 Sep '13

12 Sep '13

Hallo, how can I move a domain consisting of 3 chains using mouse mode/ move selection? I will use chain A: 6-121, chainB: 7-103, Chain C: 6-103. The selection by command line takes always the longest number 121 for all three chains - A:6-121, B:7-121, C:6-121. Greetings, Jürgen (Chimera production version 1.8 (build 38824) Windows8)

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How to modify a structure to put some atoms in a plane....
by Sergio Garay 12 Sep '13

12 Sep '13

Hi all I'm trying to put a Nitrogen atoms of a Nitro group in the same plane that a imidazol ring, but until now with no success. I've tried using modify structure and changing the bond and geometry of the carbon to which the Nitrogen is joined, but it did not work. I attached an image with the problem. I've also tried to minimize the structure using AMBER ff (despite I know that this ff is not appropriate for small organic molecules) but it can fix the problem. May be I'm not clear enough so, I summarize: I want to put the Nitro group in the same plane of a imidazol ring (look at the picture, please). Any advice will be appreciated. [image: Inline image 1] Sergio -- Sergio Garay Dr. en Ciencias Biológicas Facultad de Bioquimica y Cs. Biológicas Universidad Nacional del Litoral Santa Fe - Argentina C.C. 242 - Ciudad Universitaria - C.P. S3000ZAA Argentina Ph. +54 (342) 4575-213 Fax. +54 (342) 4575-221

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Solvent Channel Dimensions
by Thompson, Matthew K 12 Sep '13

12 Sep '13

How can I measure the dimensions of a solvent channel in a protein? The channel is clearly visible after the surface in generated. In addition, the cavity can be created with Surfnet. Something like "Measure and Color Blobs" does not give the dimensions I need. I am interested in the width of the channel at its most narrow point. Thanks Matt

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Re: [Chimera-users] automatically calculated labels for quantitative tomography data
by Tom Goddard 11 Sep '13

11 Sep '13

Hi Martin, Thanks for the detailed explanation. I think a generalization of your idea might be useful to more people. Basically you could create a text label including an automatically updated numeric value, but that number could be calculated from a density map contour level, or a molecular dynamics trajectory energy value, or a distance between a residue and ligand during a conformational change -- in other words the numerical value could measure many things. The case of just density map threshold levels has some utility, but since the same value can be seen in the volume dialog where you actually change the value, it seems more for presentation than analysis. The general tool would take significant work, because Chimera doesn't have a framework for providing measurement updates. We are working on the next generation of Chimera and this graphical label idea is interesting because we are looking at having fewer dialogs -- even a Chimera in a web browser. Maybe instead of using a separate volume dialog you could just display the threshold levels like you have done, and simply use the mouse to directly change those values in the graphics window. You've mentioned movie making. The labeling in your figure can be included in Chimera movies now, and the values can change, and labels fade in and out. Most Chimera movies are made with command scripts and these label operations would use the 2dlabels command. Granted with your proposed tool it might be easier to make the movie, but I'd say only slightly easier, because the overall movie making is not simple and the labels are just one small aspect. I have worked with Carolyn Larabell's group looking at their x-ray tomography data using Chimera some years back. They concluded Amira better suited their needs for doing segmentation. Here is a demo I gave showing what Chimera could do with their Pombe cell tomography. http://www.cgl.ucsf.edu/chimera/data/ncxt-feb2008/xraytomography.html Tom On Sep 11, 2013, at 5:05 PM, Martin de Jonge wrote: > Hi Tom, > > Thanks for the reply. I guess you raise a few questions, so I'll try and pick them individually. > > 1. the concept > >>> Or maybe it doesn't need a separate window -- you might just be able to say display colored labels in the graphics (e.g. "Zn 11" "Cu 47" "Ca 1500") for several density maps that list both an element name and the current contour level. You could control those levels using the Volume Viewer dialog and the labels would automatically update. > > Yes, I think that's what I was thinking. In the image I linked you to earlier, the threshold levels were manually entered into the color key. Every time the threshold changed these entries had to be updated also. In the new implementation one might enter into the color key dialog: "Ca {#3 * 1000}", where "#3" represents the threshold level for model number 3, the " * 1000" indicates multiplication by 1000, and the curly brackets indicate the presence of a substitutional expression. (Of course you would want to make this syntax consistent with Chimera!) > > The thinking about the simple mathematical operations is that sometimes the reconstructed data is only relatively scaled, and needs a final conversion factor to become a 'real' unit. Alternately, one might have data in ng/µm^3 and wish to convert to ug/cm^3, in which case multiplication by some power of 10 would be nice. In other cases the mathematical function could enable a change from units of mass/volume to molarity. Don't worry too much about this idea - it is probably not worth the effort, and can probably be performed by other means. > > 2. the user base > > I agree that at present there is not much call for this feature, however I note that two forms of x-ray tomography have recently entered the quantitative domain: x-ray fluorescence tomography (now performed by 10+ groups around the world) and soft-x-ray absorption tomography, performed most notably by the group of Larabell and LeGros at the UCSF (see eg http://www.ncbi.nlm.nih.gov/pubmed/21360734) (have you made contact with that group? I /think/ they render with Amira, but they are putting heaps of computing effort into automated segmentation of their LAC data, and I imagine this could be a good team to collaborate / share resources with). But I appreciate that the tomography user base would not rise to 1000 within 5 years, and therefore that this extension may not be practicable. > > I think this feature would be useful for the other main Chimera user base, which I gather is the protein crystallography (PX) / molecular modelling / imaging people. I guess my thinking here is that one of the great features of Chimera is the ability to explore the dataset dynamically, by adjusting thresholds, rotating, etc. This applies also for molecular / PX data. For all cases it is useful to adjust the threshold (being now generalised to either linear absorption coefficient (LAC), elemental concentration, or electron density) to see different features. This is usually done with the slider, or from the cmd line, but can also be scripted in movies etc. My suggestion (that I think you have understood in general, but repeat for clarity) is that there could be a mechanism to display the present threshold in a key on the display window. As such it could be one (electron density, LAC) or several (elemental concentration) numbers that are transferred into the key. > > Why am I saying this? Just in case you think there might be some other call for this feature from the other user base! I leave it to you to decide, and fully accept your knowledge of the Chimera user base! > > Thanks for the response, and for developing a great piece of software. Let me know if there is anything I can do in return (besides acknowledgement / citation!). > > [PS - I took the chimera-users off the response just in case you think the Larabell comments are politically sensitive. I don't mind if they go out - I stand by my words - I'll leave it to you to decide, and to forward the mail to the development team as you see fit.] > > Yours, > > Martin de Jonge > > > > > > -----Original Message----- > From: Tom Goddard [mailto:goddard@sonic.net] > Sent: Thursday, 12 September 2013 8:16 AM > To: Martin de Jonge > Cc: chimera-users(a)cgl.ucsf.edu > Subject: Re: [Chimera-users] automatically calculated labels for quantitative tomography data > > Hi Martin, > > Your elemental abundance tomography is interesting. I'm not sure I understand your Chimera suggestion. Do you mean there would be a separate window that lists the threshold levels for Zn, Cu, Fe, Mn density maps in type-in fields and adjusting the values would both change the contour level (as is done by the Volume Viewer tool) and update the labels displayed in the graphics window (as with the 2D Label tool)? Or maybe it doesn't need a separate window -- you might just be able to say display colored labels in the graphics (e.g. "Zn 11" "Cu 47" "Ca 1500") for several density maps that list both an element name and the current contour level. You could control those levels using the Volume Viewer dialog and the labels would automatically update. (By the way, did you know you can display 6 or 10 histograms in the Volume Viewer dialog instead of the normal limit of 3? Use volume dialog menu Features / Data Display Options and change "Maximum number of Histograms.", and use Features / Save Default Dialog Settings if you want that to be the default for future Chimera uses.) I don't understand what you mean by "include simple mathematical operations". > > If I understand your basic idea, I think it is specialized enough that only a few Chimera users would use it. I'm not sure I've ever seen a figure like yours with values that correspond directly to density map levels, because usually the density map values have some meaningless normalization. Most often presentation figure keys need to be created in an entirely custom way appropriate to the content of the figure. Still I think the feature you suggest would be cool, but given the hundreds of improvements people have requested we try to work on ones that lots of Chimera users (500 or 1000) will benefit from, or requests that allow you to do something that isn't otherwise possible. > > Tom > > > On Sep 10, 2013, at 7:56 PM, Martin de Jonge wrote: > >> Hi all, >> >> this might sound like a strange feature, but I use Chimera to render quantitative tomography data. I typically render somewhere between 2 and 6 separate elements (i.e., Zn, Cu, Fe, Mn, etc) and present these with a colour key, along with a numerical value to indicate the threshold concentration (typically in mmol or similar unit). There is an example of such data in: http://www.pnas.org/content/107/36/15676/F1.expansion.html >> >> When exploring such data it is very useful to adjust the display threshold, as various anatomical features appear at very different concentration levels. My suggestion / request is to have a numerical field in the colour key that can be linked to (eg) the per-model thresholds to indicate the concentration threshold at that moment. This would be particularly useful for making movies for presentations and articles. >> >> Some thoughts on useful properties of this numerical field: >> >> - it should inherit the colour of the colour-key label that it is associated with (or be able to select to be inheritable) >> - it could include simple mathematical operations, for when there is a simple relationship between the data and the reportable concentration eg, *, /, +, - >> - one should be able to specify the format of the number (using the usual formatting codes). >> >> thanks >> >> Martin de Jonge >> _______________________________________________ >> Chimera-users mailing list >> Chimera-users(a)cgl.ucsf.edu >> http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >> > >

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automatically calculated labels for quantitative tomography data
by Martin de Jonge 11 Sep '13

11 Sep '13

Hi all, this might sound like a strange feature, but I use Chimera to render quantitative tomography data. I typically render somewhere between 2 and 6 separate elements (i.e., Zn, Cu, Fe, Mn, etc) and present these with a colour key, along with a numerical value to indicate the threshold concentration (typically in mmol or similar unit). There is an example of such data in: http://www.pnas.org/content/107/36/15676/F1.expansion.html When exploring such data it is very useful to adjust the display threshold, as various anatomical features appear at very different concentration levels. My suggestion / request is to have a numerical field in the colour key that can be linked to (eg) the per-model thresholds to indicate the concentration threshold at that moment. This would be particularly useful for making movies for presentations and articles. Some thoughts on useful properties of this numerical field: - it should inherit the colour of the colour-key label that it is associated with (or be able to select to be inheritable) - it could include simple mathematical operations, for when there is a simple relationship between the data and the reportable concentration eg, *, /, +, - - one should be able to specify the format of the number (using the usual formatting codes). thanks Martin de Jonge

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Re: [Chimera-users] accuracy of fitting atomic structure in density map at different resolution
by Tom Goddard 11 Sep '13

11 Sep '13

Hi Andy, Do you mean how much fits vary depending on EM map resolution? I suppose you could apply Gaussian filtering to the EM map to produce a lower resolution EM map, then fit your atomic model, then see how much motion and rotation there is of a fit at one resolution from a fit at another resolution. All that is easy in Chimera. To compare different fits I would open multiple copies of the same atomic model and fit one to each different map then use the "measure rotation" command (e.g. "measure rotation #2 #3") to see how much motion there is between fits. http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/measure.html#rotation With any other fitting software you could do the same test by exporting the Gaussian smoothed maps from Chimera, fitting with other software, writing out fit PDBs with the other software and then loading those PDBs in Chimera and comparing their orientation. In that case you'd want to use the Chimera "match" command to measure the motion between models (e.g. match #2 #3 showMatrix true, the look in Reply Log for results). The "measure rotation" only reports coordinate frame motions done within Chimera, whereas "match" aligns two atomic models. http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/match.html Tom On Sep 11, 2013, at 7:13 AM, Anindito Sen <emailanindito(a)yahoo.co.in> wrote: > Hi Tom, > > Is there any method by which, we can figure out the accuracy of docking of an atomic structure into its EM density map generated at different resolutions and by different software packages? > > Thanks > > Andy > >> Dr. Anindito Sen (Ph.D) >> Department of Cell Biology & Anatomy >> Graduate School of Medicine >> University of Tokyo >> Tel & fax: +81-3-5841-3339 >

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Minimization units
by Elisabeth Ortega 09 Sep '13

09 Sep '13

Dear Chimera dev. team, I have a very simple question regarding Energy Minimization. The energy units are kcal/mol or kJ/mol? In this function, chimera uses the MMTK function to calculate the energy, and, as far as I know, MMTK energy units are kJ/mol (in share/MMMD/MMTKinter.py the units of the length are corrected to angstroms, but the energies don't). I took a look in the previous e-mails of the chimera-users list. I saw some texts that refers to the energy in kcal/mol and I am a bit confused. Thank you for your time. -- Elisabeth Ortega Carrasco, Ph.D. Student Molecular Modelling of Transition Metal Systems Group Lab. C7/153, Chemistry Department Universitat Autonoma de Barcelona Tel.: +34935812857 email.: eortega(a)qf.uab.cat

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Querie: Ligand superimposition
by Graziella Portelli 09 Sep '13

09 Sep '13

Dear Chimera Team Hope this email finds you in good health. I am using UCSF Chimeria for my de Novo drug design disseration. I am still learning the basic functions that this software offers, however have not been able to figure out the following. Basically I need to put into one picture/frame the original ligand or my receptor and the possible ligands (generated by Ligbuilder). They have the same general structure with some changes and I need to superimpose them, but show them at separate levels. Is this possible to do this for only the ligands and not the receptor protein? I eagerly await your reply, Graziella Portelli B.Pharm

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Color Isosurface in Chimera
by Gregor Weiss 05 Sep '13

05 Sep '13

Hello, I tried to color different parts of an isosurface obtained by an electron cryotomogram to point out structures more clearly. Unfortunately, I didn't figure out how I can select different areas and color them differently. Which tool fits here the best? I can determine an area and subsequent color all structures in this area with the tool "Color Zone", but I was not able to select another area and choose a different color. Thank you very much for your help! With best regards, Gregor Weiss -- Gregor Weiss, B.Sc. Summer Researchassistant Jensenlab California Institute of Technology, HHMI Mail code 114-96 1200 E. California Blvd. Pasadena, CA 91125 626-395-8848 (phone)

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about the command: match
by 韩晓东 05 Sep '13

05 Sep '13

Dear sir, it is no doubt the UCSF chimera is a very excellent software. However, when i use the command: match iterate 2.0 site2 site1, a problem appeared as follows: unequal numbers of atoms chosen for evaluation. would you kindly share me the skill to deal with this problem. thank you very much for your time. sincerely yours, xiaodong han.

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Re: [Chimera-users] Chimera hbond
by Elaine Meng 05 Sep '13

05 Sep '13

On Sep 5, 2013, at 2:40 AM, Neha Gandhi <n.gandhiau(a)gmail.com> wrote: > Hi Elaine, > > I was going through your response on chimera mailing list regarding > saving h-bond analyses during MD ensemble/movie. Either one can write > files every nth frame or save log files. Is there a way to put all the > output of the frames one by one in one single file? > > Your help is appreciated. > > -- > Regards, > Dr. Neha S. Gandhi, > Curtin Research Fellow, > School of Biomedical Sciences, > Curtin University, > Perth GPO U1987 > Australia > LinkedIn > Research Gate Hi Neha, Writing the information to the Reply Log does not save a file. You can accumulate multiple sets of results in the Reply Log and then, at the end, save the Reply Log contents to a single file. The "findhbond" command has two separate options to write results to a file ("saveFile true") and to write results to the reply log ("log true"). <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/findhbond.html> You can save the contents of the Reply Log (in menu under Favorites) to a file with its Save button. I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco P.S. please send chimera questions to chimera-users(a)cgl.ucsf.edu (CC'd on this message) instead of to me directly - thanks!

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display atom by coordinates
by Bala subramanian 03 Sep '13

03 Sep '13

Friends, I am trying to visualize the md movie of a channel protein. In every frame, i want to display only those ions whose Z coord ranges from -10 to 35 (zcoor of the channel) to make the movie. Is there any simple way ?. Precisely displaying atoms with a condition. Thanks in advance, Bala -- C. Balasubramanian

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Linking two chains in a PDB file
by Maxwell Cherf 03 Sep '13

03 Sep '13

Hi Sir/Madam I have a PDB file of three proteins bound together (in one model). I would like to fuse the N terminus of one protein to the C terminus of another protein by adding a peptide linker between the termini. Is it possible to do this using Chimera? So far, I have built a linker and joined it to one of the termini, but doing that combined the linker and all proteins in the file into one model. Now, I can't connect the free end of the linker to the other terminus because they are part of the same model. Any help would be much appreciated! Best, Gerald Cherf, PhD candidate Cochran Lab Bioengineering Department Stanford University

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problem with SwissSidechain plugin installation
by Thomas Evangelidis 03 Sep '13

03 Sep '13

Greetings, I have a problem with SwissSidechain Chimera plugin in Linux 86_64 (Centos 6.3). I followed the instructions yesterday and could use it to create a D-peptide: http://swisssidechain.ch/visualization/chimera.html However today I can't. I tried to add it several times to Preferences->Tools->Locations without any luck. I even did a fresh install of the current stable release and rebooted but I still can't use it. I remember I encountered similar problems in the past. Do you know what's wrong? Thomas -- ====================================================================== Thomas Evangelidis PhD student University of Athens Faculty of Pharmacy Department of Pharmaceutical Chemistry Panepistimioupoli-Zografou 157 71 Athens GREECE email: tevang(a)pharm.uoa.gr tevang3(a)gmail.com website: https://sites.google.com/site/thomasevangelidishomepage/

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help
by rajan sreekanth 30 Aug '13

30 Aug '13

Hi, I had morphed two conformations (open and close) of my protein using 'Morph Conformations' tool. I want know whether we can save the coordinates capturing the intermediate states? Something like an NMR ensemble consisting of the open-intermediate states-close conformations as a single PDB file? Thanks Sreekanth

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Re: [Chimera-users] building a peptide
by Elaine Meng 30 Aug '13

30 Aug '13

Hi Kumud, You would just specify the phi and psi angles for "turn" when building the peptide. You can specify a different phi and psi for each residue if you want, in the peptide building dialog. You do not have to use the values supplied for alpha and beta, you can enter any values, as described in the instructions: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/editing/editing.h…> Also, in a peptide structure that already exists, you can change phi and psi for each residue, either ...by rotating the bond interactively (see the Adjust Torsions tab in Build Structure): <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/editing/editing.h…> or ...by changing the "phi" and "psi" attribute values in the Selection Inspector (select an amino acid residue in a peptide or protein, click green magnifying glass near bottom right of Chimera window to open the Inspector, Inspect: "Residue" and change the values for "phi angle" and "psi angle") <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/inspection.html> However, it is up to you to specify reasonable values. You can check the Ramachandran map by using the "Ramachandran plot" function in the Model Panel (under Favorites in the menu). <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/modelpanel.html> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/ramachandran/rama…> Although it is possible to build a whole protein with different secondary structures, it would probably have many severe problems (packing etc.) and the basic peptide-building in Chimera is *not* intended for this purpose. You might want to look into using some other program to predict structure instead, or modify an existing protein structure instead of building the whole thing from scratch. There are probably hundreds of programs and dozens of web servers to predict protein structure, but it is beyond the scope of the chimera-users list and my knowledge to discuss the possibilities. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Aug 29, 2013, at 11:50 PM, Kumud Agarwal wrote: > Hi, > Thank you for your help. > Is there any way to build a beta sheet in Chimera? How can I introduce > turns in between the strands in beta sheet using the build structure > option in chimera?

1 0

Chimera VTK file reader
by Tom Goddard 29 Aug '13

29 Aug '13

Hi Andrew, I added a VTK file reader -- in tonight's Chimera daily build. It handles vtk structured points files in ascii format like the one you gave me. Your file had many -32768 values which seem to indicate regions where you don't have data and normal data values in a range 0 to 55. This makes the histogram display of data values in Chimera worthless because the data range is 33000 but the meaningful range is 55. Chimera is only able to show the whole range. You might want to use some other value to indicate "no data", like -1 if negative values are not valid. Tom > On Aug 6, 2013, at 10:09 AM, Andrew VanBenschoten wrote: > >> Hi Elaine, >> I hope all is well! Quick question for you: I have a 3D .vtk file (attached) that I want to be able to view in Chimera. This is one of the diffuse scatter maps that we discussed earlier: nearly identical to X-ray diffraction patterns except that the data values are applied to entire voxels as opposed to points. Any suggestions as to what I could try? Thank you so much! >> >> -Andrew >> <out.vtk> > >

2 1

building a peptide
by Kumud Agarwal 28 Aug '13

28 Aug '13

Hi I am very new to Chimera. I am using Chimera version 1.8. I am trying to build a peptide in chimera in beta strand conformation using build structure option but the generated peptide did not show beta strand. Why is it so? Thanks, Kumud Agarwal IIT Bombay India

2 1

Make bonds in a large polypeptide
by Francesco Pietra 27 Aug '13

27 Aug '13

Hello; Is there a limit in the number of atoms when using the function "make a bond"? I was trying that in a polypeptide of 450 standard residues (I made it a single model) and it did not work. Just to not be cryptic, that need arises from having modeled by special techniques the initial portion of the polypeptide. Now I would like to replace that portion with the modeled one. I had restrained with rmsd-colvars the dihedrals of a short stretch of alpha helix, so that I could align the modeled portion with the polypeptide. thanks francesco pietra

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some questions about new features, in particular MD
by Lionel Nauton 24 Aug '13

24 Aug '13

Hello I was very pleasantly surprised to discover a molecular dynamics module in the latest version of chimera, I used already "MD movie" to see the dynamics with NAMD made, but the ability to make dynamic from chimera is a real plus, thank you for that. in spite of this, one thing I do not understand why the minimization phase is parallelizedin the dynamics module and is not in standard mode, is a planned evolution, I'm too impatient? Second, in the latest version (21-08-2013), I can not read trajectories files from GROMACS , I saturate the RAM (16 GB and 7 GB swap) and the program exits.the same dynamics made with NAMD in .dcd formatworks well, any idea ? that's all thanks for your very good job.

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Re: [Chimera-users] Automatic struts for 3D printing?
by Hurt, Darrell (NIH/NIAID) [E] 23 Aug '13

23 Aug '13

Ask and it shall be given! Thanks for the explanation! -- Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62B, MSC 2135 Bethesda, MD 20892-2135 Office: 301-402-0095 Mobile: 301-758-3559 Web: BCBB Home Page<http://www.niaid.nih.gov/about/organization/odoffices/omo/ocicb/Pages/bcbb.…> Twitter: @niaidbioit<https://twitter.com/niaidbioit> Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. From: Tom Goddard <goddard(a)sonic.net<mailto:goddard@sonic.net>> Date: Friday, August 23, 2013 1:44 PM To: Darrell Hurt <darrellh(a)niaid.nih.gov<mailto:darrellh@niaid.nih.gov>> Cc: "chimera-users(a)cgl.ucsf.edu<mailto:chimera-users@cgl.ucsf.edu>" <chimera-users(a)cgl.ucsf.edu<mailto:chimera-users@cgl.ucsf.edu>> Subject: Re: [Chimera-users] Automatic struts for 3D printing? Hi Darrell, You can get struts between a protein and ligand with the current command -- just include the ligand atoms in the argument to the struts command. For example, open 2ghb struts @CA|ligand&element.C This is just a fancier atom specification that says consider atoms named CA or ligand carbon atoms. Here's a picture of the result. [cid:E793C582-C88D-4680-B08B-DC92C52D671B@cgl.ucsf.edu] Another tip. Yesterday I added command "~struts" that removes all struts or "~struts ligand" that removes all struts involving ligand atoms. You can use any atom specifier and remove the struts to those atoms. Tom On Aug 23, 2013, at 10:27 AM, "Hurt, Darrell (NIH/NIAID) [E]" wrote: Hi Tom, I've been playing with the command and it works very well. I really like the "replace" feature for trying several strut options without having to delete the previous ones. Thanks Elaine! You've already given me much. Thank you! One additional feature that we've thought of would be automatically create these kinds of struts to small molecule ligands. The way I thought to do this would be to use the same algorithm you've already implemented, but extend it to check if a ligand is present. If so, then struts would be created from the designated macromolecular atoms (@CA or @P) to the "heavy" (non-hydrogen) atoms of the ligand(s). I think that your "loop" parameter would prevent too many struts from being created. This would make the algorithm even more automated! Thanks! Darrell -- Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62B, MSC 2135 Bethesda, MD 20892-2135 Office: 301-402-0095 Mobile: 301-758-3559 Web: BCBB Home Page<http://www.niaid.nih.gov/about/organization/odoffices/omo/ocicb/Pages/bcbb.…> Twitter: @niaidbioit<https://twitter.com/niaidbioit> Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. From: Tom Goddard <goddard(a)sonic.net<mailto:goddard@sonic.net><mailto:goddard@sonic.net>> Date: Thursday, August 22, 2013 3:46 PM To: Darrell Hurt <darrellh(a)niaid.nih.gov<mailto:darrellh@niaid.nih.gov><mailto:darrellh@niaid.nih.gov>> Cc: "chimera-users(a)cgl.ucsf.edu<mailto:chimera-users@cgl.ucsf.edu><mailto:chimera-users@cgl.ucsf.edu>" <chimera-users(a)cgl.ucsf.edu<mailto:chimera-users@cgl.ucsf.edu><mailto:chimera-users@cgl.ucsf.edu>> Subject: Re: [Chimera-users] Automatic struts for 3D printing? Hi Darrell, I improved the struts command today so it automatically replaces the previous struts if you run it a second time with the same set of atoms but different parameter values. This avoids having to delete the first set of struts with model panel -- much easier to use. Will be in tonight's daily build. Improvement suggested by Elaine Meng. If you really do want to keep multiple sets of struts for the same atoms use the struts command option "replace false". Tom On Aug 21, 2013, at 2:27 PM, "Hurt, Darrell (NIH/NIAID) [E]" wrote: Hi Tom, OMG! You're amazing! I'll certainly give this a try and let you know how it works. I really like the "loop" parameter. It seems more robust and will produce more evenly spaced struts than the second "distance" parameter I tried to explain. Thank you! Darrell -- Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62B, MSC 2135 Bethesda, MD 20892-2135 Office: 301-402-0095 Mobile: 301-758-3559 Web: BCBB Home Page<http://www.niaid.nih.gov/about/organization/odoffices/omo/ocicb/Pages/bcbb.…> Twitter: @niaidbioit<https://twitter.com/niaidbioit> Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. From: Tom Goddard Date: Wednesday, August 21, 2013 5:06 PM To: Darrell Hurt Cc: "chimera-users(a)cgl.ucsf.edu<mailto:chimera-users@cgl.ucsf.edu><mailto:chimera-users@cgl.ucsf.edu><mailto:chimera-users@cgl.ucsf.edu>" <chimera-users(a)cgl.ucsf.edu<mailto:chimera-users@cgl.ucsf.edu><mailto:chimera-users@cgl.ucsf.edu><mailto:chimera-users@cgl.ucsf.edu>> Subject: Re: [Chimera-users] Automatic struts for 3D printing? Hi Darrell, I added a "struts" command to Chimera -- in tonight's daily builds. I've attached your picture of hemagglutinin with struts and a similar picture made with the new struts command and also a picture of a tRNA (4tna) with a small number of struts made in Chimera. [cid:2AFCE3A1-824B-4430-8153-A5616DAE2C5E@cgl.ucsf.edu<mailto:A5616DAE2C5E@cgl.ucsf.edu><mailto:2AFCE3A1-824B-4430-8153-A5616DAE2C5E@cgl.ucsf.edu<mailto:A5616DAE2C5E@cgl.ucsf.edu>>][cid:54ACB2C8-EF27-4A47-A8B0-8718D93CAF28@cgl.ucsf.edu<mailto:EF27-4A47-A8B0-8718D93CAF28@cgl.ucsf.edu><mailto:54ACB2C8-EF27-4A47-A8B0-8718D93CAF28@cgl.ucsf.edu<mailto:EF27-4A47-A8B0-8718D93CAF28@cgl.ucsf.edu>>] [cid:7CBA5018-1ED2-48AD-BD7B-5D6F71E439C4@cgl.ucsf.edu<mailto:BD7B-5D6F71E439C4@cgl.ucsf.edu><mailto:7CBA5018-1ED2-48AD-BD7B-5D6F71E439C4@cgl.ucsf.edu<mailto:BD7B-5D6F71E439C4@cgl.ucsf.edu>>][cid:960E041D-8A30-4F42-8DB2-28758F7F411E@cgl.ucsf.edu<http://cgl.ucsf.edu><mailto:960E041D-8A30-4F42-8DB2-28758F7F411E@cgl.ucsf.edu<http://cgl.ucsf.edu>>] The Chimera command for the hemagglutinin model struts is struts @CA length 7 loop 30 I decided to try a different algorithm in Chimera for adding struts from the one in the Jmol code. The Chimera struts command uses two parameters. It finds all pairs of C-alpha atoms within a distance of 7 Angstroms of each other. Then it considers those from shortest to longest distances. It adds a strut if the two atoms the strut would join are more than 30 Angstroms away via bonded connections. Basically it adds struts up to a given maximum length so that C-alphas are connected via bonds and struts by no more than a maximum loop length. The maximum strut length (7 Angstroms) and maximum loop length (30 Angstroms) are the two parameters. For the tRNA model I used 15 and 80 and use P atoms instead of CA atoms (command "struts @P length 15 loop 80"). Here's roughly what the Jmol code does, that I decided not to copy 1) make struts short (less than 7 Angstroms), 2) make struts join residues at least 6 residues apart in polymer, 3) space out struts, ends of different struts no closer than 6 residues, 4) include as many struts as possible meeting spacing and length constraints, 5) put a strut within 3 residues of the end of each polymer. The exact details of how it does this would take a long explanation -- which is my main reason for not copying it. The algorithm of the Chimera struts command is easily and precisely described above and produced reasonable struts for the half dozen test cases I tried. But it may prove not as good as the Jmol approach -- experience will tell -- and I can change it if needed. Here is and example using all available strut command options struts @CA length 7 loop 30 radius 0.75 color blue name struts_7_30 fat true model #5 Any set of atoms can be specified as strut end points, radius is the strut cylinder radius, color is the strut color, name is the name of the pseudo-bond model created for the struts (struts can be hidden using Model Panel), fattenRibbon sets a fatter ribbon style better for printing (can adjust as desired with Ribbon Style Editor, menu Tools / Depiction), modelId is the model number you want for the strut pseudobonds. Struts can span multiple models, or be restricted to just a part (e.g. one chain) of a model. The command will get documented in the Chimera User's Guide. Tom On Aug 16, 2013, at 7:02 PM, "Hurt, Darrell (NIH/NIAID) [E]" wrote: Hi Tom, Thanks. This is some of our best stuff. For our material, the struts are vitally important or the whole thing crumbles. We use so many struts that a script is really important to doing this efficiently. I have no idea how it will work in a monochrome plastic printer. However, there are some plastic printers emerging on the market now that can print in two colors plus a support material. That might help with distinguishing between structure and strut. One idea is to print both the struts and the building supports in the same material and then dissolving all that, leaving just the protein. You're right about the struts being too short. They would be pointless along a helix. So I think there is a hard-coded minimum strut distance to prevent struts within the helix, but a user-settable parameter for the maximum strut distance. This is especially important in protein complexes. The pink and baby blue blobs are glycosylation on the surface of the proteins. These are modeled in using the glycoprotein builder: http://glycam.ccrc.uga.edu/ccrc/gp/index.jsp?tool=crystallography&option=ff 99:glycam06 If you think this is cool, you've got to check out what Kawakami Masaru is doing with 3D printed molecules: http://www.youtube.com/watch?v=NVtE_AS3jbI http://dx.doi.org/10.1063/1.4739961 Thanks! Darrell -- Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62B, MSC 2135 Bethesda, MD 20892-2135 Office: 301-402-0095 Mobile: 301-758-3559Web: BCBB Home Page <http://www.niaid.nih.gov/about/organization/odoffices/omo/ocicb/Pages/bcbb .aspx#niaid_inlineNav_Anchor> Twitter: @niaidbioit <https://twitter.com/niaidbioit> Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. On 8/16/13 8:46 PM, "Tom Goddard" wrote: Hi Darrell, Your plastic models are super cool. I'm jealous -- we don't have a color printer. I had no idea you were adding so many struts. I'm afraid it would look less attractive in one color. I see that some models are ribbon only and some have the residues depicted as surface blobs -- none of your pictured models used spheres and cylinders for atoms and bonds. That helps avoid confusing the struts for molecular bonds. I'm a puzzled by your dozens of pink blobs in image 3 and 7 and cyan blobs in image 9 in each case connected by lots of sticks. They look like individual residues but are too far apart to be a polypeptide I think -- maybe many copies of a small ligand? The algorithm for placing struts sounds quite simple. Chimera has ribbon splines that go exactly through the C-alphas, and can also join side chains to a ribbon even when the C-alpha is not on the ribbon. So I think that won't be a problem. The Jmol strut code I looked at looked more complex than what you describe. If it simply chose short distance struts wouldn't you get a bunch of unneeded struts say within one alpha helix, and maybe lack some long range struts that are needed to hold everything together? In any case, if we come up with an algorithm, or just want to copy the Jmol code, it looks very easy to add to Chimera. I can probably do an implementation in half a day. The main thing is to figure out exactly what the algorithm should do. Maybe I can put something in next week. Tom On Aug 16, 2013, at 5:16 PM, "Hurt, Darrell (NIH/NIAID) [E]" wrote: Hi Tom, I've been printing ribbon/cartoon and surface representations of proteins and nucleic acids for many years using a Z Corp machine. I've also done some "ball-and-stick" and "VDW-sphere" kinds of prints. Often we print substrates in "stick" mode and connect the sticks to the ribbon using manually-placed struts. We will continue to use our Z Printer, but we are also buying a "desktop" 3D printer that more people can afford. It is an "FDM" printer similar to the uPrinter your webpages describe. The algorithm used by the George Phillips script is a little different (and perhaps simpler) than the one you describe. It has two parameters: (1) the maximum length of a strut and (2) the minimum closeness of any two struts. The second parameter is a little funky; I'll describe it below. The script first identifies all pairs of C-alphas (or pairs of initial phosphates on the backbone for nucleic acids). Then it creates "pseudobonds" (the struts) between all of those pairs which conform to the maximum length parameter. The next step is to cull the list of pseudobonds according to the minimum distance parameter so that you don't get struts everywhere. Here's where it gets kind of funky because I don't know how this distance is calculated. Either it is calculated from the starting end of a pseudobond (which is what I expect from what I can see of the results of the script) or it does it from center/centroid of the pseudobond. The script also adjusts some parameters to thicken the ribbons, sticks, etc. and increase the triangle count of the exported mesh. This usually works great, but there is one little problem because the struts are calculated to put the ends of the struts at the C-alpha positions. For helices, this usually isn't a problem because the helix ribbon/cartoon goes through the C-alpha position. But for strands which are drawn on a spline of the C-alphas, the struts sometimes either go through or do not reach the ribbon, making the struts useless. Using some standard tools in PyMOL, I force the ribbon to go through the C-alpha positions everywhere there is a strut terminus. In this way, the ribbon and the ends of the struts correspond and the print is strengthened without sacrificing the aesthetics of the splined ribbon. I've attached the results of this script for both the mesh and the actual print (the "ribbon.jpg" and "ribbon.png" images). Of course, printing in monochrome plastic will be different, but that's what we're hoping to experiment with. I've also attached a few other pictures of our prints. George and I have discussed sharing his script with a wider audience or even publishing some kind of technical note about it. He seems willing to share it with certain limitations. Maybe we can all write something together if we build it into Chimera. We might be able to do it internally, but I would have to get my developers more familiar with the internals of Chimera first. I welcome any efforts you or others might make. Thanks, Darrell -- Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62B, MSC 2135 Bethesda, MD 20892-2135 Office: 301-402-0095 Mobile: 301-758-3559Web: BCBB Home Page <http://www.niaid.nih.gov/about/organization/odoffices/omo/ocicb/Pages/bc bb .aspx#niaid_inlineNav_Anchor> Twitter: @niaidbioit <https://twitter.com/niaidbioit> Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. On 8/16/13 6:14 PM, "Tom Goddard" wrote: Hi Darrell, Here are some of the molecule models we have printed in plastic. http://www.cgl.ucsf.edu/Outreach/technotes/ModelGallery/index.html and a description of the printer we used http://www.cgl.ucsf.edu/Outreach/technotes/uprint.html Chimera does not currently have any tool to automatically add struts, although I've done this by hand in Chimera. For instance the heptatis B virus pentamer on the above web page had part of an icosahedral cage made from cylinders underneath it to hold the proteins on the virus surface together. One thing you'll see is that all our printed molecules came from surface depictions in Chimera (made with molmap command). I'm not sure if we successfully printed and ball and stick models via STL or VRML. We tried years ago and I recall them falling apart because where the spheres and cylinders intersected it put no plastic. Basically an atom sphere and bond cylinder are two surfaces and for points inside two surfaces (or any even number of surfaces I think) the printer places no plastic. So overlapped cylinders and spheres didn't hold together. This seems to be a printer driver issue -- how it takes a surface and makes a solid out of it. I don't know that we've tried with our newer printers at UCSF -- maybe it works now. Have you successfully printed ball and stick models exported from Chimera? What kind of printer? Now about automatically adding struts -- probably would not be hard. The struts code I saw online http://idp1.force.cs.is.nagoya-u.ac.jp/jmol/src/org/jmol/modelsetbio/Al ph aPolymer.java didn't have a clear description of the algorithm the use, but it would just take an hour to study it. I could see aiming to add struts that 1) are cylinders between atoms, 2) are short, 3) make the whole model one connected piece, 4) make every contiguous N (50) residues connected in at least 3 places (2 probably being continuations before and after and one being a crossbridge) to other residues for rigidity, 5) not put connections at the ends where they would be easily confused for real biological connections, 6) struts should not look like real bonds -- maybe make them fatter or better square cross-section. Actually that rigidity constraint is more complex -- probably don't want to have two large pieces connected to each other through only one bond. I recall printing some ribbon models in ABS plastic with ribbon cross-section pretty small -- half a centimeter. With 100 residues and no cross bridges the model is very flexible and easy to break. Could you provide a picture of a ball and stick model with struts to give a better idea of what you are shooting for? Tom On Aug 16, 2013, at 2:32 PM, "Hurt, Darrell (NIH/NIAID) [E]" wrote: Hi everyone, We are assembling an open data portal or "exchange" for producing "ready-to-3D-print" files for biological molecules, EM data, and other imaging data using some automated pipelines. A little bit more on our project can be found here: http://www.hhs.gov/open/initiatives/ignite/3d-printing-exchange.html A few years ago this came up on the "dev" discussion board: http://www.cgl.ucsf.edu/pipermail/chimera-dev/2011/000800.html In the email thread above, it mentions a script by George Phillips called "struts.py" that was modified for use in RasMol. I am familiar with his version of this script for PyMOL. It works very well and I have been using it for years. However, the VRML from PyMOL is sometimes buggy. I like the exports from Chimera much better, including the X3D2VRML and X3D2STL utilities. If I could get the same functionality of this "struts" script in Chimera, that would be one less thing I need to go to PyMOL for (the list is getting shorter and shorter!). We're looking at doing it here, but I would welcome any contribution from the Chimera community if something already exists. Do you have anything? Is this script something of interest? Anyone interested in contributing to our "exchange" database/web portal? I would love any feedback you might have. Thanks, Darrell -- Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62B, MSC 2135 Bethesda, MD 20892-2135 Office: 301-402-0095 Mobile: 301-758-3559 Web: BCBB Home Page<http://www.niaid.nih.gov/about/organization/odoffices/omo/ocicb/Pa ge s/bcbb.aspx#niaid_inlineNav_Anchor> Twitter: @niaidbioit<https://twitter.com/niaidbioit> Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. 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