- Chimera-users - RBVI Mailing Lists

vrml lighting
by Dougherty, Matthew T 12 Feb '14

12 Feb '14

I have a multiple vrml models that vary by scale. 1, 10 & 100 I notice the lighting significantly drops off as the scale increases. When I have another model, say PDB, that is in approximate relation (ie, viewable in regards to the volume size similar to the vrml files volumes); the PDB file looks good regardless of size (eg, tRNA or ribosome). I can increase the brightness to compensate (10-20) but it washes out the PDB models when brightness goes beyond 2. is the lighting handled differently between these different types of models? Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine

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superimposing two structures based on a specific selection
by David Martin 10 Feb '14

10 Feb '14

Chimera 1.8 on Windows I have been trying to align (superimpose) models based on a specific conserved region. Unfortunately Chimera doesn't seem to do what the documentation claims it does. I run (example): match #0:5-15@CA,20-30@CA #1: 5-15@CA,20-30@CA and get an RMSD calculation (more on this below), but no movement of the model occurs. I specify 'move true show true' as options. Still no movement but I have a transformation matrix. Unfortunately this is not in a form that can be understood by Transform Coordinates. How do I persuade my structures to superimpose on the specific atoms? The RMSD calculation appears to be broken. If I take the command rmsd #0:5-15@CA,20-30@CA #1: 5-15@CA,20-30@CA then I will get a number If I then run rmsd #0:5-15@CA,20-30@CA #1: 5-15@CA,21-31@CA I get exactly the same number. In fact, if I specify atom sets of different sizes (as long as it is not the first block) then I continue to get exactly the same number rmsd #0:5-15@CA,20-30@CA #1: 5-15@CA,20-35@CA This should fail but doesn't Have I completely misunderstood what Chimera should be doing here? ..d The University of Dundee is a registered Scottish Charity, No: SC015096

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Query on introducing an external protein
by Aditya Padhi 06 Feb '14

06 Feb '14

Dear All, I want to place a protein molecule (appx. 20 kDa in size) into a viral capsid loop region which is about 7 amino acid long. What I want to do is to remove the 5 amino acids out from the loop region and place the 20 kDa protein, so that the loop region can accommodate the 20 kDa protein. I am finding it difficult as the co-ordinates of both the molecules are different. Although, this is not related to MD simulation or associated stuff, it would be grateful if I can get some suggestions. Thanking you, Regards Aditya.

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Query on introducing a protein
by Aditya Padhi 04 Feb '14

04 Feb '14

Dear All, I want to place a protein molecule (appx. 20 kDa in size) into a viral capsid loop region which is about 7 amino acid long. What I want to do is to remove the 5 amino acids out from the loop region and place the 20 kDa protein, so that the loop region can accommodate the 20 kDa protein. I am finding it difficult as the co-ordinates of both the molecules are different. Although, this is not related to MD simulation or associated stuff, it would be grateful if I can get some suggestions. Thanking you, Regards Aditya.

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Question about "Color Zone" and "Render by Attribute"
by Helge Paternoga 04 Feb '14

04 Feb '14

Hello, I have a question regarding the colouring of surfaces and their caps. I am trying to recreate the colouring by hydrophobicity on capped surfaces as shown in (on the right side): http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/2dlabels/2dlabels.… So first I've opened the "Render by Attribute" dialog and assigned "kdHydrophobicity". This only coloured the surface and not the surface cap though. I am assuming this is done by "Color Zone"? Indeed this colours the surface cap but I have one problem: The colouring of the surface is different between "Render by Attribute" and "Color Zone" and I don't know why. The differences are small but I would like to know which one is more accurate (intuitively I would say the one from "Render by Attribute"). I've played around with the radius of "Color Zone" but this doesn't achieve the same colouring as "Render by Attribute". So my question is: How can I achieve the same surface colouring by "Color Zone" as in "Render by Attribute"? Does it have something to to with "bondzone" or the hierachy in which the atoms apply their respective colour in "Color Zone"? Thanks for reading! Helge

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Question about opening mrc and PDB files
by Min Woo Sung 03 Feb '14

03 Feb '14

Hi, This is Min Woo Sung from Texas A&M University. I was using Chimera to see EM structure(.mrc file) and wanted to put a PDB file to fit that in EM map. I'm wondering if I can use Chimera to analyze the volume, size or domains of these two files for the purpose of analysis. I saw one PDB file seemed much bigger that EM map when I opened it in Chimera. Do I have to normalize the size of any files? If so, how can I do that? Any suggests would greatly appreciated. Best regard, Min Woo Sung

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Creating output with IDATM naming
by Nikolay Igorovich Rodionov 03 Feb '14

03 Feb '14

Hi, Does anyone know a way to rename all of the atom names in a PDB file to their IDATM types, so that a new PDB file can be generated with the IDATM naming scheme? Best, Nikolay Rodionov

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Zoom problem?
by Damien Larivière 03 Feb '14

03 Feb '14

Dear all, I try to zoom in the scene, to get very close to my model shown here below. I cannot be closer than in the image below, the zooming function is at its maximum. When zooming, I get the error message : /refocus to continue scaling/ I do not know whether it is a bug or something I'm doing wrong. Thanks for your help, Damien

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Need help in Coulombic surface coloring
by Haresh Tukaram More 30 Jan '14

30 Jan '14

Hi, I tried to get the Coulombic surface coloring for one of the protein that I modified by removing certain residue at the C-termini and then mutated some residues to the non-natural amino acid 5,5,5-trifluoroleucine using Swisssidechin option. I am getting this error which I am not able to understand. Disabled GPU programs because a graphics driver bug was encountered while compiling a vertex shader. #0, chain A: COMP #0, chain B: COMP #0, chain C: COMP #0, chain D: COMP #0, chain E: COMP C:\Program Files\Chimera 1.8.1\bin\mscalc.exe 1.400000 2.000000 1 MSMSLIB 1.3 started on Local PC Copyright M.F. Sanner (March 2000) Compilation flags Surface CC TFLE.pdb, category main, probe radius 1.4, vertex density 2 22 connected surface components Total solvent excluded surface area = 10393.6 component areas = 8599.46, 624.842, 225.9, 216.153, 81.7059, 54.8894, 54.839, 48.0624, 45.9525, 43.9588, 41.5667, 39.1204, 38.7549, 37.0513, 35.5418, 33.6712, 32.9167, 28.9293, 27.8262, 27.7523, 27.7319, 26.9429 Total solvent accessible surface area = 10372 component areas = 9971.67, 202.012, 92.2225, 70.7414, 13.8165, 4.12717, 3.62753, 3.24856, 2.597, 1.1866, 1.72654, 1.33137, 1.08737, 0.962375, 0.64812, 0.231422, 0.40193, 0.120068, 0.0570046, 0.0515394, 0.0674059, 0.0311705 No SEQRES records for combination (#-2147483648.-2147483648) chain A; guessing terminii instead No SEQRES records for combination (#-2147483648.-2147483648) chain B; guessing terminii instead No SEQRES records for combination (#-2147483648.-2147483648) chain C; guessing terminii instead No SEQRES records for combination (#-2147483648.-2147483648) chain D; guessing terminii instead No SEQRES records for combination (#-2147483648.-2147483648) chain E; guessing terminii instead Chain-initial residues that are actual N terminii: #-2147483648.-2147483648 MET 27.A, #-2147483648.-2147483648 MET 27.B, #-2147483648.-2147483648 MET 27.C, #-2147483648.-2147483648 MET 27.D, #-2147483648.-2147483648 MET 27.E Chain-initial residues that are not actual N terminii: Chain-final residues that are actual C terminii: #-2147483648.-2147483648 TFLE 67.A, #-2147483648.-2147483648 TFLE 67.B, #-2147483648.-2147483648 TFLE 67.C, #-2147483648.-2147483648 TFLE 67.D, #-2147483648.-2147483648 TFLE 67.E Chain-final residues that are not actual C terminii: 424 hydrogen bonds Hydrogens added Charge model: AMBER ff12SB Assigning partial charges to residue TFLE+TFLE (net charge +0) with am1-bcc method Running ANTECHAMBER command: C:/Program Files/Chimera 1.8.1/bin/amber12/bin\antechamber -ek qm_theory='AM1', -i c:\users\haresh~1.pol\appdata\local\temp\tmpipssqi\ante.in.mol2 -fi mol2 -o c:\users\haresh~1.pol\appdata\local\temp\tmpipssqi\ante.out.mol2 -fo mol2 -c bcc -nc 0 -j 5 -s 2 (TFLE+TFLE) Cannot automatically determine charges for residue TFLE+TFLE; Run AddCharge tool manually to add charges and then rerun ESP Can someone please tell me a step by step procedure to make this work. Thanks & Regards, Haresh

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Re: [Chimera-users] Coloring map by curvature
by Tom Goddard 29 Jan '14

29 Jan '14

Hi Joel, I don't think surface curvature will be helpful understand the differences between two EM maps. But I was curious what it would look like. So here's a Python script and an image on a simulated map at 15 Angstroms. You use the script by opening your map, selecting the surface (ctrl-click on it), then open the curvature.py script (menu File / Open…). Here's a description of the method it uses from the comments at the top of the curvature.py file. # Color selected surface pieces by mean curvature. # # Gray at the average curvature value over the surface, and blue and red # at +/- 3 standard deviations of curvature values across the surface. # # The curvature is estimated from the vertices and normals of the triangulated # surface in simple way which will show artifacts from non-isotropic meshes. # For each triangle edge it computes the normal vector rotation from one vertex # to the other divided by the edge length. The vertex mean curvature is the # mean of the curvatures computed for each edge. # And the steps to make the example image open 1grl molmap #0 15 grid 2 model #1 select #1 open ~/Desktop/curvature.py Tom On Jan 29, 2014, at 9:40 AM, Joel Meyerson wrote: > Hi Darrell, > Thanks for the tip! I hadn't considered mesh lab but that link you sent looks promising. I'll also wait to see if Tom has any further suggestions. > Joel > > > On Wed, Jan 29, 2014 at 11:44 AM, Hurt, Darrell (NIH/NIAID) [E] wrote: > Hi Joel, > > I love Chimera and use it all the time. However, a quick-and-dirty solution to your problem might be to try Meshlab. It is kind of buggy software, but can be very useful. Here's a tutorial/blog entry that I found in a quick search. At the very least, it describes what I think Tom was communicating about enhancing surface shading: > http://meshlabstuff.blogspot.com/2010/03/mean-curvature-cavity-map-zbrush-a… > > FWIW, > 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 > > > 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: <Meyerson>, "Joel [F] (NIH/NCI)" > Date: Tuesday, January 28, 2014 9:08 PM > To: Tom Goddard > Cc: "chimera-users(a)cgl.ucsf.edu List" <chimera-users(a)cgl.ucsf.edu> > > Subject: Re: [Chimera-users] Coloring map by curvature > > Hi Tom, > I have cryo-EM maps for two conformations of a protein, both in the 15 Angstrom resolution range. The conformations are visibly different, but I am also interested in seeing where they differ in terms of their surface curvature, as it could have bearing on how I interpret the conformations. If there's any other info I can provide just let me know. > Thanks! > Joel > > > On Tue, Jan 28, 2014 at 7:36 PM, Tom Goddard wrote: > Hi Joel, > > No, Chimera does not compute surface curvature. It would not be too hard to make a Python script that computed it and used it to color a surface. The main trouble is defining numerically the curvature for a triangulated surface at each vertex. Why are you interested in this? Is the idea to simulate ambient occlusion lighting where surface cavities are dark and projections are brighter? Is the idea to try it on EM maps or molecular surfaces? > > Tom > > > On Jan 28, 2014, at 2:29 PM, Joel Meyerson wrote: > > > Hi, > > Is it possible to color a map based on surface curvature? > > Thanks, > > Joel > > _______________________________________________ > > Chimera-users mailing list > > Chimera-users(a)cgl.ucsf.edu > > http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users > > >

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