- Chimera-users - RBVI Mailing Lists

chimera visualization
by Valerio Chiarini 02 Sep '15

02 Sep '15

Dear Elaine, I would like to produce images from chimera showing an NMR bundle structure (backbone only) with stick-represented residues each one belonging to different single structures. I know it´s possible to do it with pymol but unfortunately the structures superimposition is not as good as in chimera. Would it be possible? Thank you in advance, Valerio

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Rapid residue identification near ligands
by Korbin West 01 Sep '15

01 Sep '15

Greetings all, We need to be able to easily assign ligands to a chain (or chains) and to rapidly ID the residues in contact with it. I believe Chimera processes the structures and immediately displays ligands and maybe contacts, so it "knows" this information somehow. Does anyone know of a way to identify these easily and quickly so we can analyze large numbers of files? Also, if the output could be in the form of a text file or such that would be beneficial as well. Thank you all for your help. Best, Korbin West Wabash College

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make a movie showing the process from an ASU model to the complete model of virus
by 李智海 01 Sep '15

01 Sep '15

Hi, I just obtained an atomic model of the asymmetric unit of an icosahedral T=7 virus capsid , and I want to make a movie to play the whole process from the ASU model to the full capsid model by imposing its icosahedral symmetry. Please show me some examples of the command lines to generate such kind of movies. Thanks! Best regards! Zhihai

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Hydrogen bonding calculation issues with PDB2PQR/AMBER/CHIMERA
by Fenton Heirtzler 31 Aug '15

31 Aug '15

Hello- I’m trying to use CHIMERA to model the hexameric hydrogen bonding of isophthalic acid. I’m just an organic chemist, not a computational chemist. The PDB2PQR subroutine is returning the reply “Error encountered: No heavy atoms found!”. Here is sequentially what I have done: 1. A pdb file of isophthalic acid hexamer was imported. 2. The covalent bond lengths and angles were set to realistic ones. 3. The names of the concerned atoms were defined in the Build Structure/Modify Structure/Change Modified Residue’s name box, as described in the User Guide (i.e., Cac, O2, O3 and H) 4. The default limits of 3.4 Å and 30° were used 5. The AMBER force field was chosen. Thanks very much Fenton (PS – I’m a private person, not associated with either academia nor industry) -- Dr. Fenton Heirtzler Phone: +1-301-312-5145 On LinkedIn <http://www.linkedin.com/in/fentonhorgchem/> Skype: fentonheirtzler Supporter of the International Day of Climate Action <http://www.350.org/> *********

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Query related to chimera
by Akhilesh Verma 31 Aug '15

31 Aug '15

Dear Manager, Is it possible to do Protein protein docking using chimera program? Your response will be highly appreciated. Thanking you. -- Sincerely yours, *Akalesh Kumar Verma* *Morehouse School of Medicine* *Microbiology, Biochemistry & Immunology* Atlanta, Georgia, USA Pin / Zip: 30329 *Mobile: +1 (678) 497-6404* *http://www.msm.edu/ <http://www.msm.edu/>* _______________________ ______________ *Personal Disclaimer:--* *Any information contained in this e-mail and/or any attachments is confidential and only intended for reception and use by the specified person. If you are not the intended recipient, please return the email to the sender and delete it afterwards. In this case any copying, forwarding, printing, disclosure and use are strictly prohibited.* *_________________* *__________*

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How can I can calculate or know Gibbs free energy from UCSF Chimera
by Awah.Chidiebere.U＠mh-hannover.de 28 Aug '15

28 Aug '15

Dear Colleagues, Thanks for developing such wonderful tools as Chimera for molecular dynamics analysis of structure. Please I have two questions: 1. Is it possible to calculate Gibbs free energy from complexes on UCSF Chimera, for examples when complexes are solvated? 2. On building structures , is it possible to simulate how a given complex could bind DNA oligos , for example when one makes changes in single nucleotides and ask a given DNA binding TF structure to bind it on Chimera? I would look forward to your response to these questions. I would also be very happy if I could speak by phone with the administrators. Thanks. Best wishes, Chidiebere U Awah MD Msc PhD student , Molecular Medicine Hannover Medical School , Germany.

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Re: [Chimera-users] a question relate to Chimera
by Elaine Meng 27 Aug '15

27 Aug '15

On Aug 26, 2015, at 6:27 PM, Smith Liu <smith_liu123(a)163.com> wrote: > Dear Elaine, > Thanks for the reply. > > Here let us consider the first question on "a particle has a diameter of 100 pixels ", which I think may be done by Chimera with your help. From http://www.imagescience.de/fsc/index.htm, we can download a software which can be used to calculate the resolution of the map by FSC. When we use that software for calculation, we need to input "Filling degree" D/L, where the value of object size D in voxels, and the L, the linear ssize of the 3D volume (x, y,z). A typical value of "Filling degree" D/L would be 0.66, indicating that 2/3 of the linear width of the 3D volume is filled by the object. > > Thus will you please show me by Chimera how can we know "the value of object size D in voxels"? > > I am looking forward to getting your reply. > > Best regards. > Smith Dear Smith, Please send Chimera questions to chimera-users(a)cgl.ucsf.edu (instead of to me directly). Others may be able to answer your questions better than I can, for example in this case where I don’t know the answer. For linear size of the whole volume (the map), we already discussed that you can see the number of grid units (voxels) in X,Y,Z to the right of the dataset name in the Volume Viewer dialog, and see angstroms per grid unit in the Features: Coordinates section of Volume Viewer. You could multiply the values to get the size of the map in angstroms. <http://plato.cgl.ucsf.edu/pipermail/chimera-users/2015-August/011437.html> <http://plato.cgl.ucsf.edu/pipermail/chimera-users/2015-August/011433.html> However, I don’t know how you could measure the voxel size of the object in Chimera. As far as I know you could only estimate it by eye, or by measuring angstrom dimensions, converting to grid units, and then multiplying them to roughly estimate the area of the object in voxels. It would only be an estimate, assuming your object is not a perfect circle or square. See previous posts on measuring angstrom dimensions in a map: <http://plato.cgl.ucsf.edu/pipermail/chimera-users/2015-January/010609.html> <http://plato.cgl.ucsf.edu/pipermail/chimera-users/2014-January/009503.html> My guess is that people would normally get this information from the software used in the original data collection, not by doing measurements in Chimera. Best, 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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Re: [Chimera-users] Icosahedral net from PDB
by Tom Goddard 27 Aug '15

27 Aug '15

Hi James, There are a few Chimera commands that let you show a icosahedral cage around a virus PDB model. Basically you use the sym command to make the virus capsid from the PDB asymmetric unit, then use the shape command to make the cage, then optionally use the meshmol command to show the cage with cylinders instead of lines. For example, open 2bbv sym #0 surf true shape icos radius 200 lattice 1,1 meshmol #2 3 color gold #3 There’s also a video showing how to make the cage for an electron microscopy map http://www.cgl.ucsf.edu/chimera/videodoc/cage/index.html <http://www.cgl.ucsf.edu/chimera/videodoc/cage/index.html> Here is the command documentation for more info about sym, shape, meshmol commands: http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/framecommand.html <http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/framecommand.html> Tom > On Aug 27, 2015, at 5:11 AM, Geraets, James A > Hi Tom, > > A colleague of mine has told me that you have previously made available a script for displaying icosahedrally-symmetric pdb files on an icosahedron net. Would you happen to still have it? I can’t find any sign of it online… > > Cheers (and thanks for your continued work on Chimera) > > James > > ---------- > > James Geraets > EU Marie Curie Actions Fellow > AIROPico Project > > Institute of Biotechnology > PL 56 > FI-00014 University of Helsinki > Finland

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addgrp command
by UCSF-xiaobowan 26 Aug '15

26 Aug '15

Hi all, I am Xiaobo Wan, a postdoc at UCSF. I would like to learn how to add chemical groups (such as methyl) or change chemical atoms (Fluorine to Nitrogen) using the command in Chimera because I have thousands of compounds to do the same modification. I know the Build Structure in the Graphic interface can do this. I am not sure whether the addgrp command was supported by chimera now. Best, Xiaobo

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color suggestion
by Dougherty, Matthew T 26 Aug '15

26 Aug '15

1) button on the model panel to bring up the color editor that will edit the model selected. 2) very short pulldown menu on the color editor of the primary & secondary colors, along with black, white and gray50. Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine ===========================================================================

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Re: [Chimera-users] a question relate to Chimera
by Elaine Meng 26 Aug '15

26 Aug '15

On Aug 25, 2015, at 6:16 PM, Smith Liu <smith_liu123(a)163.com> wrote: > Dear Elaine, > Here there is a sentence "a particle has a diameter of 100 pixels and the width of the reconstruction box is 256 pixels". Will you please tell me by Chimera how can I know the diameter of the particle and the width of the reconstruction box, as described in the cited sentence? > > I am looking forward to getting a reply from you. > Best regards. > Smith Dear Smith, It is recommended to send Chimera questions to chimera-users(a)cgl.ucsf.edu (CC’d here) instead of to me directly. I don’t know where that sentence came from, so I’m not even sure it is a Chimera question. By “pixels” maybe the authors mean grid units. They probably just knew this about their own data without trying to get it from Chimera, but at least for the width of the box, you can see the grid dimensions just to the right of the dataset name in the Volume Viewer dialog. <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/fram…> Best, 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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on point-group symmetry used for the 3-D calculation
by Smith Liu 25 Aug '15

25 Aug '15

Dear All, By chimera, can we know the point-group symmetry used for the 3-D calculation? Best regards. Smith

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on voxel size measured in angstroms
by Smith Liu 25 Aug '15

25 Aug '15

Dear All, Will you please tell me by Chimera how can we know the voxel size measured in angstroms? Smith

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is the connection present?
by Dmitry 25 Aug '15

25 Aug '15

Dear Colleagues, I have 3d tetramer volume density where I fitted known x-ray structure of monomer (to each unit of tetramer). I want to check the inter-monomeric space, whether there is connections between 2 monomers. Is there a command or script that checks the presence of contacts between bounds of 2 structures? Thank you Sincerely, Dmitry

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Electrostatic Potential Visualization
by Chun, Minju 25 Aug '15

25 Aug '15

Hello, I am an intern working with Chimera, and I was wondering if I was missing a plug-in that calculated electrostatic potential. I attempted to load a dx and cube file to emulate electrostatic potential, but there seemed to be a problem finding/reading the files(perhaps I'm doing this wrong too). I thought that if I calculated electrostatic potential directly with Chimera, I could see electrostatic potential. It says on your website that Chimera can calculate the electrostatic potential with APBS: "electrostatic potential calculated with Adaptive Poisson-Boltzmann Solver<http://www.poissonboltzmann.org/apbs/> (APBS); the APBS<http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/apbs/apbs.html> tool in Chimera runs this program via web service provided by the NBCR<http://nbcr.ucsd.edu/>" Do you have a tutorial that goes in more detail in how to calculate potential with APBS? Thank you, Minju Chun

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Flattening of coloured icosahedron
by R.I.Koning＠lumc.nl 24 Aug '15

24 Aug '15

Is it possible to flatten a coloured icosahedron surface? I have an electron density of a virus, and using shape icosahedron and colour icosahedron surface and surface colour I can colour it according to this density. I would really like to generate a flattened icosahedron (compared to the flatten icosahedron command) from the coloured icosahedron surface. In order to get a 2D map of the colours. Is this possible somehow in Chimera? Is it otherwise possible to export the icosahedron with the coloured surfaces and try in another program (like Maya of Cinema4D?). Best regards, Roman Koning

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layering problem
by Joseph Atherton 20 Aug '15

20 Aug '15

Hi! I'm trying to make videos at the moment but I have a problem with layering, as in the model seems to be 'hiding' behind the density even when the density is transparent. This occurs when I set transparency also in the model, even at low transparency (e.g command #19:transparency 5,a,r #0:259-271). See the example attached- the left hand most part of the model, and the ADP is hidden when their transparency is non-zero. Can I prevent this? Cheers, Joe

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Re: [Chimera-users] [chimera-dev] distance measurements
by Elaine Meng 19 Aug '15

19 Aug '15

Hi Feixia! Yes, you could use Chimera to measure all lysine CA-CA distances in many structures, but it would require some scripting to loop through the structures, find the lysines, and do the measurements. There is some information on looping through structures and running Chimera commands here: <http://www.rbvi.ucsf.edu/chimera/docs/ProgrammersGuide/basicPrimer.html> Now, for each structure, you might imagine the script should first find all the lysines and then use the “distance" command on each pairwise combination, substituting in the proper residue numbers. However, there is an easier way with the “findclash” command. You can use it for multiple distance measurement in a single command. For example: open 2gbp findclash :lys@ca test self overlap -1000 log true … will measure all distances among lysine CA atoms in structure 2gbp and list results in the Reply Log (open from Favorites menu). The -1000 in the command says to measure the distance even if the atoms are “overlapping” by -1000 (more than 1000 angstroms apart). The last column in the results is the atom-atom distance, and they are given in order of increasing distance, in this case: 464 contacts atom1 atom2 overlap distance LYS 191.A CA LYS 189.A CA -1.802 5.562 LYS 227.A CA LYS 223.A CA -2.137 5.897 LYS 300.A CA LYS 246.A CA -2.800 6.560 LYS 169.A CA LYS 164.A CA -4.676 8.436 LYS 270.A CA LYS 276.A CA -4.677 8.437 [… several lines removed …] LYS 276.A CA LYS 203.A CA -53.705 57.465 LYS 276.A CA LYS 137.A CA -56.756 60.516 LYS 61.A CA LYS 137.A CA -56.829 60.589 LYS 58.A CA LYS 137.A CA -59.598 63.358 464 contacts The log contents can be saved to a text file, for example see <http://plato.cgl.ucsf.edu/pipermail/chimera-users/2008-October/003184.html> However, your log would have a huge amount of results for all structures and it might be hard to tell which results go with which structures, so another possibility would be to save a separate file of results for each structure, and in that case your script would need to substitute in an output filename, e.g. findclash :lys@ca test self overlap -1000 saveFile ~/Desktop/2gbp.log See findclash documentation for all the options. Then you can embed the command in the python looping script as described in the first link above. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/findclash.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 On Aug 18, 2015, at 8:36 AM, Feixia <feixia.chu(a)unh.edu> wrote: > Hi there, > I am interested in retrieving distance information from large dataset in an automatic fashion. For instance, can we use Chimera to get the distances between lysine alpha-carbons of current PDB entries. Presumably, we can download all PDB structures on our local desktop, and just call functions one structure at a time. I wonder if we can do that with Chimera. Your advice will be highly appreciated. > Best, > Feixia

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measure the vertical distance between aromatic planes
by Wang, Bing 19 Aug '15

19 Aug '15

Hi Chimera, Is there a way to measure the vertical distance of two planes in the structure? I do know how to measure the angle between two planes or one line and one plane by the Axes/Planes/Centroids in Chimera. I don't need the distance of two centroid of two planes. I do need the vertical distance of two planes. Could you please show me in detail? Thanks a lot! Bing Wang

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How to select a plane from the command line
by JUAN PABLO REYES VALVERDE 17 Aug '15

17 Aug '15

Dear UCSF Chimera Team: Please, I would much appreciate your advice on the following: First issue: Given a number of planes - calculated/created through the 'define' command - I would like to select one of them, with some command entered at the command line .... How can I do it? The reason why I want to select it through the command line, and not by directly by clicking at it at the axes/planes/centroids table, is because later I would like to use the command inside a runCommand statement, in a Python/IDLE script (with *.py extension) ... Second issue: By the way, do you think this piece of code could work? Assume that the desired plane is already selected .... I want to internally handle the plane as 'p1' in my Python code: p1= chimera.Plane() from chimera import selection p1= selection or perhaps this single instruction ..... p1= chimera.selection Let me try to explain: Within my Python code, I want to have a way to make reference to a plane created by the 'define' command ( should I call it a ' handle'? ... not sure whether it is the correct term ...). Well, I hope that I managed to make it sufficiently clear ... Thanks in advance for your kind attention. Cheers, Juan Dr. Juan Pablo Reyes Valverde Laboratorio de Neurobiología Molecular y Celular (D15) Instituto de Neurobiología UNAM Campus UNAM Juriquilla Boulevard Juriquilla 3001 Querétaro, QRO CP 76230 MÉXICO Tel +52 (442) 2381064

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Charges for PTR+DT
by Amali Guruge 17 Aug '15

17 Aug '15

Dear all, I have to prepare the pdb structure 1K4T to my study. When I do the dock prep process, it gives net charges as, PTR+DT -2 TGP +0 I added charges for standard resides by AMBER ff12SB. For other residues, I added charges by Gasteiger method. My problem is why PTR+DT gives -2 charge? I am not familiar with this one. <http://www.google.lk/intl/en/options/> Can anyone help me? Thank you.

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Modification of ribbon scaling to intersect guide atoms at termini and chain breaks?
by Oliver Clarke 14 Aug '15

14 Aug '15

Suggestion - would it be possible at some point in the future to add a new ribbon scaling option (I guess in Chimera 2.0 or later) so that all internal residues behave like the current “Bspline” scaling, but residues at termini or chain breaks behave like “cardinal” - where the ribbon path exactly intersects the guide atoms? The attached image illustrates the kind of situation this would address - where one wants to show secondary structure in cartoon, but pick out a loop or structural feature of interest in backbone or CA+sidechains, with no ugly discontinuities between the all-atom and ribbon representations. This would allow seamless mixing of nice looking cartoon representation and nice looking backbone or C-alpha+sidechains representation, which I don’t believe is possible at the moment. Cheers, Oliver. Also, in case anyone finds it useful, the following alias applied to a selection or model will generate the CA+sidechains representation depicted below: #Show CA trace with sidechains #Usage: ca_and_sidechains #model_id (or selection/atom-spec) alias ^ca_and_sidechains sel $1; namesel tmp; ~ribbon tmp; ~disp tmp; sel tmp&@CA&protein; repr stick sel; disp sel; setattr m stickScale 1.00 tmp; sel side chain/base.without CA/C1'&tmp; repr stick sel; disp sel; setattr b radius 0.1 sel; color orange tmp; color byhet tmp; sel @CAA |@CB; namesel tmp2; sel tmp&tmp2; repr stick sel; setattr b radius 0.1 sel; sel @CD,N&:pro&tmp; disp sel; repr stick sel; setattr b radius 0.. 1 sel; ~sel

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~select doesn't work on axes?
by Oliver Clarke 14 Aug '15

14 Aug '15

The command "~sel” does not unselect selected axes/planes/centroids - is this intended, and/or is there another way to unselect these objects from the command line? Also, is there a command to undisplay selected axes/planes/centroids? I can only figure out how to do so from the GUI but I would like to do this from the command line, as when you have many axes defined and only want to hide a few it would be easier to have an equivalent of “~disp sel” rather than hunting for the specific axes in the Axes/Planes/Centroids list. Cheers, Oliver.

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odd chimera benchmark performance
by Dan Lin 13 Aug '15

13 Aug '15

Hello: I was wondering if anyone had any experience tracking down performance problems in chimera. I've noticed that I am getting really sluggish performance when managing a lot of atoms, even when everything is shown as backbone traces only. To take a look at the performance, I ran the benchmark and got the following numbers: Volume benchmark scores surface mesh contour solid recolor 981 1291 280 589 393 Null Wire Stick BStick Ribbon Sphere Ops 6249.5 158.7 1.5 0.9 27.4 0.4 89.3 compared to a benchmark posted on the website of the same graphics card: 2125 2026 302 512 491 213 492 452 3259 169 128 Apparently I'm getting awful benchmarks for most of the molecule benchmarks, while the volume performance is pretty comparable. I re-ran the molecule benchmarks to make sure they were reproducible and got pretty much the same numbers. Would anybody have any suggestions for figuring out what's going on? For reference, I'm running ubuntu 12.04 with up to date nvidia drivers for a GTX 560 Ti. Thanks, Dan

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axis-axis distance definition
by Oliver Clarke 13 Aug '15

13 Aug '15

Quick question - how is the distance between two axes (as reported by Axes/Planes/Centroids) calculated? Is it the minimum distance between two axes (I guess yes, because it does not seem to match the center to center distance)? And does it assume the axes are of infinite length, and calculate the displacement required for them to intersect, or does it measure the minimum distance between the axes with the length and end positions as displayed? Cheers, Oliver.

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