- Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] Hidden water molecules
by david gae 15 Apr '16

15 Apr '16

Hi Mike, No problem. You can also save each chain and heteroatom in CHIMERA by doing “select:.a” -> GUI-> Save PDB and “select:.b”->GUI-> Save PDB OR run a simple script below: f = open('chainA.pdb','w') f2= open('chainB.pdb','w') pdb = open("1c1d.pdb","r") for line in pdb: if line[:4] == 'ATOM' and line[21:22] == "A": f.write(line) if line[:6] == 'HETATM' and line[21:22] == "A": f.write(line) if line[:4] =='ATOM' and line[21:22] =="B": f2.write(line) if line[:6] == 'HETATM' and line[21:22] == "B": f2.write(line) Hope this helps, Dave > On Apr 15, 2016, at 1:16 AM, Michael Sharkey <michael.sharkey(a)ucd.ie> wrote: > > Thanks Dave > > I had saved a copy containing one of the two chains in the asymmetric unit, not realising that the waters didn't come with the protein (and heteroatoms). > > Problem solved > > Thanks again (for a very swift response) > > Mike > > On 6 April 2016 at 16:23, Gae, David Hyon <DavidHyon.Gae(a)ucsf.edu <mailto:DavidHyon.Gae@ucsf.edu>> wrote: > Hi Mike, > > If you haven’t messed around the PDB file in WordPad. i think doing “ disp: hoh “ in command line should show the water. > > > Hope this help, > Dave > > On Apr 6, 2016, at 7:38 AM, Michael Sharkey <michael.sharkey(a)ucd.ie <mailto:michael.sharkey@ucd.ie>> wrote: > > > > Hi > > > > I'm trying to visualise water molecules associated with the crystal structure of an enzyme (specifically PDB ID: 1C1D). They're listed when I open the pdb as a text file using WordPad, but I can't for the life of me get them to appear on the screen when I try to visualise the structure in Chimera (v. 1.10.2). > > > > What am I missing? > > > > Thanks in advance > > > > Mike > > > > -- > > > > _______________________________________________ > > Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu <mailto:Chimera-users@cgl.ucsf.edu> > > Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users <http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users> > > > > > -- > Michael Sharkey PhD, > UCD School of Biomolecular and Biomedical Science, > Conway Institute, > University College Dublin, > Tel. 01-7166932 >

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Chimera crashes when visualizing large structure
by Klose, Thomas 15 Apr '16

15 Apr '16

Dear all, I am trying to visualize a rather large structure (8280 chains with 620 amino acids each) as ribbons in Chimera, starting from a biological unit. I was able to reduce the required memory to something my Linux machine can handle (i7 with 64GB memory) by providing a file with just C-alpha atoms. Chimera successfully displays the copies as surfaces, and also starts to convert all the displayed chains into ribbons (chains as ribbon: finished?), but then becomes unresponsive, runs with 100% CPU usage on one core for several hours and finally crashes. Is this a known problem/limitation and is there some workaround to display such large structures? Thanks, Thomas

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chemical structure
by kotakis xristos 15 Apr '16

15 Apr '16

Dear Sir/Madam, I have a siRNA duplex (21nt) of a given sequence and I would like to generate the chemical structure of that in a single file (e.g. pdf) What do you suggest? looking forward to your response thanks in advance, yours, Dr. Christos Kotakis

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question
by A G Szabo 14 Apr '16

14 Apr '16

When I called up the Chimera icon today the following window popped up. I was still able to fetch a PDB file. Comments? Arthur G. Szabo Professor Emeritus Chemistry and Biochemistry Wilfrid Laurier University Waterloo ON Canada.

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even more
by A G Szabo 14 Apr '16

14 Apr '16

The first response to a message that I send to Chimera is one received from chimera-users-bounces(a)cgl.ucsf.edu In this response from Chimera there is a line in the text: The reason it is being held: Post by non-member to a members-only list If I am a registered user am I not a member? What is the definition of a member? Thank you Arthur G. Szabo Professor Emeritus Chemistry and Biochemistry Wilfrid Laurier University Waterloo ON Canada.

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morph map tool EM density
by Franken, L.E. 14 Apr '16

14 Apr '16

Hi all, I am fairly new to using chimera and was wondering if there is a way to get more control over the path that is calculated when morph map is used for two EM density maps that are different conformations. When I use the tool now it will change the visible density a great deal and rather than rotating only a certain part of the map the result seems quite confusing to look at as the whole structures move. Is there a way to fix some areas while alowing to morph subregeons? Or does anyone have a better idea on how to approach this? the map is a dimer and the change is suposed to be a difference in rotation between the two monomers. Ideally I would show this by fixing two monomers ontop of each other and allowing the other halfs to move. Thank you in advance, Linda

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more
by A G Szabo 14 Apr '16

14 Apr '16

For some reason unknown to me it appears that my registration has expired. One serious matter is that all the PY files no longer seem to exist on the Chimera site, even though they are listed on the right side of the window. I trust that I can have my registration renewed. Arthur G. Szabo.

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issues
by A G Szabo 14 Apr '16

14 Apr '16

I just sent Chimera an email regarding a window that opened up regarding expiry of my registration. I was able to fetch a PDB file, 1GPA But the menu actions do not appear to work as they used to. I try to hide the selected ribbon, and instead of hiding it the color changes. Eventually with some persistence I can hide one of the chains. Do I have to reregister? Thank you Arthur G. Szabo

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Re: [Chimera-users] Density display with CHIMERA
by Elaine Meng 14 Apr '16

14 Apr '16

On Apr 13, 2016, at 9:27 AM, F.Xavier Gomis-Rüth <fxgr(a)ibmb.csic.es> wrote: > Dear Elaine, > I am encountering problems while trying to display a fragment of a structure from a PDB file superimposed > with its Fourier map. When I load the latter, it is presented displaced from the model and I cannot get it centered > onto it. All other features (contouring, mesh/solid style, etc.) work fine, it's just that atoms and density do not superimpose. > I've tried it with different space groups, just for the case it was a problem in a particular library, but without success. > I am working on a Mac, I don´t know if there is a problem, and I am using CCP4 maps. > Any suggestions would be very welcomed! > Best wishes, > Xavier > -- > <fxgr_signanew.jpg> Dear Xavier, I don’t know where or from what program these files came frome, so it is hard to say why the coordinates don’t match up. In some cases the map file does not include information that aligns its coordinates with the corresponding atomic structure, or maybe the map file header does have this information but it is not in a format understood by Chimera. You can change the offset of the map in Chimera, if you know what it should be. After opening the map, in the Volume Viewer dialog choose Features… Coordinates, and in the resulting options you can change origin index, spacing, etc. However, I don’t know how to figure out what values are needed, if you don’t already have that information. The options are explained here: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/fram…> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/volu…> It is generally recommended to send Chimera questions to chimera-users(a)cgl.ucsf.edu (CC’d here), especially in certain areas where others know more than I do. 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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PDB file created by a protein—protien docking tool ZDOCK can not opened by Chimera
by 赵思雨 13 Apr '16

13 Apr '16

Excuse me： Thanks for your good tool.I'am a student studying bioinformatics.I have met a trouble.My PDB file created by a protein—protien docking tool ZDOCK.It can not opened by Chimera.But can opened by Jmol and DS ViewerPro Trial.While the graphic created by Chimera is more beautiful. One of the PDB file is in the accessory. Thanks Siyu Zhao

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mmCIF lacks peptide bonds
by Michael Blaisse 13 Apr '16

13 Apr '16

Hello, I'm solving a crystal structure and as I'm preparing to submit the final structure to PDB, I used the PDB_Extract tool to convert my final refined .pdb to an mmCIF file as per the request of PDB. After I do this, however, I noticed that if I open the CIF file in Chimera, it does not have any connectivity between the residues. This does not appear to be a problem in PyMOL. Less importantly, I also had a question about the Sequence view in Chimera. I have a break in my chain due to unmodelled residues, and I noticed that if I float my cursor over a residue in the sequence, it shows the correct residue number at the bottom of the window, however the numbering at the side of the sequence view window is wrong after the break because it does not take the chain break into account. I appreciate any advice/help people can offer. Thanks, Mike

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Electrostatic potential surface area
by Yasser Almeida Hernández 13 Apr '16

13 Apr '16

Hi all, I did some calculations of the electrostatic potential using APBS and Delphi. I want to calculate the surface area of a positive patch in my protein. There is a way to select and compute the surface area/patch, filtering by the electrostatic surface value? Thanks in advance Yasser

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Re: [Chimera-users] fivefold rotate command
by Cheng-Chen Xu 13 Apr '16

13 Apr '16

Hi Tom, Very nice example. Really big help! Just updated to the newest Chimera version, done! Thanks again for your time and patience. Chen > -----Original Messages----- > From: "Tom Goddard" <goddard(a)sonic.net> > Sent Time: Wednesday, April 13, 2016 > To: "Cheng-Chen Xu" <xucc(a)wh.iov.cn> > Cc: > Subject: Re: [Chimera-users] fivefold rotate command > > Hi Chen, > > Yes you can rotate the pentamers of a T=1 icosahedral capsid in Chimera using the “turn” and “sym” commands. The hardest part is figuring out the direction of the 5-fold axis. Here’s an example > > open 2bpa > open 2bpa > sym #1 update true coord #0 > # Select opposite pentamers by hand (10 monomers total) with mouse and up-arrow key > define axis sel > turn a1 5 model #1 > > I open 2 copies of the virus, the first copy (#0) just serves as a reference coordinate system when I move the second copy (#1). The sym command makes the 60 copies of #1 for the full virus and the “update” option says to update all the positions when copy #1 moves relative to #0. Then I define an axis (called a1) by selecting two opposite pentamers including the #1 monomer. Then I rotate monomer #1 about that axis by 5 degrees, and all the other 60 copies will move automatically to maintain symmetry. Here’s a movie illustrating the motion. > > http://www.cgl.ucsf.edu/home/goddard/temp/spin_5fold.mp4 > > Tom > > > > On Apr 11, 2016, at 8:42 PM, Cheng-Chen Xu wrote: > > > > Hi Chimera, > > Is there anyway to rotate each pentamer around its own fivefold axis separately and simultaneously when dealing with a T=1 icosahedral virus capsid? > > Many thanks, > > > > Chen > > > > > > > > > > > > _______________________________________________ > > Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu > > Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >

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Other Tools button not present in the Segment Map Dialog
by silvia desanctis 13 Apr '16

13 Apr '16

Dear all, I have performed a segmentation on my map but if I click the Shortcuts button in the Segment Map dialog I cannot see the Other Tools section where I would select the Fit, Extract, rSeg or SegLoop tools. Why not? I updated to the daily built version of Chimera just yesterday so I have no idea why this complete line of tools is missing. Greeetings Silvia

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Mirrored density artefact
by Morris, Kyle 13 Apr '16

13 Apr '16

Dear Chimera dev and community, I am using "vop cover” to extract a box of density around a PDB and making the box quite large with the following: $ vop cover #0 atomBox #1 pad 55 I have noticed in the extracted density that as I increase the pad size the true density gets duplicated and mirrored on the opposite edge of the cell containing the volume. This seems like strange behaviour to me, is there something wrong or that I am doing wrong? Many thanks for your help. Best, Kyle

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using standard OS keyboard shortcuts with Chimera?
by Jakob Suckale 12 Apr '16

12 Apr '16

Dear all, It's perplexing for newbie users that Chimera does not react to the basic keyboard shortcuts that are used across all OS applications like Cmd+S, Cmd+O, Cmd+W. Is it possible with Chimera to use those? If not, it should be enabled. I'm aware that there are special 2-letter Chimera shortcuts (http://bit.ly/1Xr5uA4) but they are more confusing for beginners and therefore also disabled by default. We see a lot of user errors like saving the session with Cmd+S, then quitting Chimera with Cmd+Q (the only standard shortcut available, I believe) and then asking why their session info has not been saved. Included standard shortcuts as a feature in one of the next releases seems like a small thing with a lot of benefit. All the best, Jakob Jakob Suckale, PhD Lecturer in Biochemistry University of Tübingen +49-7071-29-73363

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fivefold rotate command
by Cheng-Chen Xu 11 Apr '16

11 Apr '16

Hi Chimera, Is there anyway to rotate each pentamer around its own fivefold axis separately and simultaneously when dealing with a T=1 icosahedral virus capsid? Many thanks, Chen

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Color holes in mesh?
by Oliver Clarke 08 Apr '16

08 Apr '16

Hi, When I want to show electron density around, for example, a single alpha helix in a structure, there are a couple of options in chimera - one would be to use vop zone, which I don't like for this purpose, because it creates a new map that can be recontoured (so one can't see where the original map has been cut). The sop analog of this, sop zone, works quite well for the purpose, but there is no easy way that I can find to cap the holes that are created in the mesh - I want to do this so that I can make it obvious where "carving" the map has affected the shape of the resultant map, or has truncated connected regions that are not displayed. Would it be possible to add such an option in ChimeraX? Or having an option to represent the inside of a surface differently from the outside would do the trick also. For the moment I have a work around (used in the attached pic): 1. Create a mesh. 2. Duplicate the mesh, change to surface rep and set transparency to 0.001. 3. Create a copy of this surface, change the transparency to 0.99 and increase the volume level by 0.001. Cheers, Oli.

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Re: [Chimera-users] how to generate good STL code for atoms display
by Jakob Suckale 08 Apr '16

08 Apr '16

Hi David, Yep, you recalled that well despite the convoluted name. It does help with overall simplification but it does that for all structures proportionally and ribbons are well converted. It's just the atom models that are excessive. What I cannot do yet in Meshlab is get rid of all these pointless internal structures. The 5-membered ring in the attachment for example is full of invisible vertices inside that inflate the file size. There are ways to partially remove internal structures with Meshlab (http://bit.ly/1Tyzz1u) but they don't do a very good job because they typically remove some of the outer ribbon surfaces as well creating hole that need to be filled. All the best, Jakob On 7 April 2016 at 23:01, David Bhella <David.Bhella(a)glasgow.ac.uk> wrote: > I use meshlab for this I am not in front of my mac just now but from memory the filter is quadratic edge collapse decimation (or something like that). It works well to reduce the poly count. > E-mail me if you want help trying it. > Another useful tool is netfabb to repair stl files by removing unwanted shells and fixing non-manifold maps. Lately I have found surfaces from chimera don't suffer from this as much as they used to.... > > Sent from my iPad > >> On 7 Apr 2016, at 21:17, Greg Couch <gregc(a)cgl.ucsf.edu> wrote: >> >> Hi Jakob, >> >> One way to reduce the number of STL triangles generated is to lower the subdivision amount in the graphics quality section of the Effects dialog in Chimera. >> >> Another way is to load the STL output into the open-source MeshLab program, http://meshlab.sourceforge.net/, and use its tools to simplify the mesh. I have not that, so if someone has done that, please chime in, and describe which MeshLab filters to use. >> >> You may need to use both techniques to make 3D printer software work. If your 3D printer takes VRML input, I would recommend using Chimera's VRML output instead. >> >> HTH, >> >> Greg >> >>> On 04/04/2016 05:13 AM, Jakob Suckale wrote: >>> Sorry, the message was truncated. This is the missing part. >>> >>> A netfabb repair of the chromophore STL does significantly simplify >>> the model and reduce the file size from 13.7 to 5.7 MB indicating that >>> there's a lot of room for improvement in the STL export esp. of atom >>> models. >>> >>>> On 4 April 2016 at 11:54, Jakob Suckale <jakob.suckale(a)uni-tuebingen.de> wrote: >>>> Dear chimeras, >>>> >>>> Does anybody know of a good way to generate lean STL code for atom/bond display? >>>> >>>> Take this example. I'm generating STLs to 3D print GFP. Exporting the >>>> ribbon of the beta barrel generates an ok STL of 6.8MB. However, >>>> exporting the wire atom display of the chromophore generates a >>>> horribly inflated STL of 13.7MB - almost twice the ribbons file >>>> despite the tiny size (see screenshot attached). Printing the >>>> chromophore is problematic since it contains a lot of weird internal >>>> structures instead of being a clean surface model of the wireframe. A >>>> netfabb repair of the chromophore STL >>>> >>>> Looking forward to your expert ideas. >>>> >>>> All the best, >>>> >>>> Jakob >>>> >>>> >>>> >>>> Jakob Suckale, PhD >>>> Lecturer in Biochemistry >>>> University of Tübingen >>>> +49-7071-29-73363 >>> _______________________________________________ >>> Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu >>> Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >> >> _______________________________________________ >> Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu >> Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

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how to generate good STL code for atoms display
by Jakob Suckale 07 Apr '16

07 Apr '16

Dear chimeras, Does anybody know of a good way to generate lean STL code for atom/bond display? Take this example. I'm generating STLs to 3D print GFP. Exporting the ribbon of the beta barrel generates an ok STL of 6.8MB. However, exporting the wire atom display of the chromophore generates a horribly inflated STL of 13.7MB - almost twice the ribbons file despite the tiny size (see screenshot attached). Printing the chromophore is problematic since it contains a lot of weird internal structures instead of being a clean surface model of the wireframe. A netfabb repair of the chromophore STL Looking forward to your expert ideas. All the best, Jakob Jakob Suckale, PhD Lecturer in Biochemistry University of Tübingen +49-7071-29-73363

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3D viewing
by Mohamed Noor 07 Apr '16

07 Apr '16

Dear all Where can I find information on the hardware required for 3D viewing with Chimera? I am building my Linux system, so I would appreciate useful pointers. 1. IIUC, I need a Quadro card as this does not work with GeForce. What should I look for when selecting a suitable card? 2. I want to also have a second monitor. Since this is not going to be used for 3D, can I just hook up any normal monitor? Or do both monitors have to be the same model etc.? 3. I have read that I need to have a card with 3-pin DIN port. Is this true? Thanks. Mohamed

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Advice on SASA
by George Tzotzos 07 Apr '16

07 Apr '16

I have a couple of questions on Chimera’s implementation of SASA. First, I’ll try to explain briefly my problem and then ask the questions. My protein is a homodimer. There exist 3 X-ray structures of the protein in complex with serendipitous ligand as well as in complex with biological ones. The ligands bind at the interface between the two chains of the homodimer. It is not clear whether dimer formation is a crystallographic artefact. Biochemical experiments are likewise inconclusive. It has been argued that the biological ligands may stabilise the formation of the dimer. Furthermore, it has been argued that upon ligand binding some of the interface residues become buried. I’ve conducted extensive MD simulations with and without the biological ligands. I would like to test whether ligand binding has an effect on the SASA of the interface residues. 1. Can I restrict measurement of SASA to selected residues only? In other words, can I use a mask specifying the residues of interest? 2. From the documentation, I understand that the Chimera implementation of SASA is applied on single pdb structures and not on trajectories. If I use representative structures from MD clusters, should I strip the ligand before measuring SASAs? Thank you in advance for your suggestions and apologies for the long-winded explanation. Best regards George

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save gaussian volume filter as a new map?
by H. Adam Steinberg 06 Apr '16

06 Apr '16

Hi All, How do I save a map that I applied a gaussian volume filter to? I opened a cryo EMD map and then applied a gaussian volume filter to it with a width of 1.5 to clean up some of the extra detail. I would now like to save that map out of Chimera to use elsewhere. When I save the Chimera file it says “EMD-6413.map gaussian was not saved with the session.To have them included in the session it must be saved in separate volume files before the session is saved.” How do I do that? <http://www.artforscience.com/> <http://www.artforscience.com/>H. Adam Steinberg Artist & Scientist 7904 Bowman Rd Lodi, WI 53555 608/729-5944 <http://www.artforscience.com/>artforscience <http://www.artforscience.com/> Facebook <http://facebook.com/artforscience1> Twitter <http://twitter.com/artforscience> McPherson Eye Research Institute <http://www.vision.wisc.edu/>

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Adding 3D arrows (vectors) in a scene
by Henrique C. S. Junior 05 Apr '16

05 Apr '16

Dear list, Magnetic Anisotropy is a directional property and, because of that, it is useful to repreent it as a vector that crosses the molecule. Is that a way to add 3D "arrows" (vectors) using Chimera? -- *Henrique C. S. Junior* Químico Industrial - UFRRJ Mestrando em Química Inorgânica - UFRRJ Centro de Processamento de Dados - PMP

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B-weighted map
by Quentin Vicens 05 Apr '16

05 Apr '16

Hi folks, Would anyone know whether B-factor weighted maps can be calculated in Chimera? For example as an option to molmap or another tool. The goal would be to look at the correlation between a pdb and a map using "fit in map" but by taking B-factor info into account. Thanks! Quentin Quentin Vicens University of Strasbourg, France National Center for Scientific Research

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