- Chimera-users - RBVI Mailing Lists

Display solvent-accessible surface?
by Hurt, Darrell (NIH/NIAID) [E] 17 Sep '10

17 Sep '10

Hi there, I’ve tried searching the archives and found some interesting information, but nothing specific to this question. Elaine’s response was particularly helpful: http://plato.cgl.ucsf.edu/pipermail/chimera-users/2009-February/003597.html >From the documentation, it seems that Chimera only displays solvent-excluded surfaces: http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/representation.html… I understand that I can map solvent-accessibility to this surface using “Render Attributes”, but I would like to display the actual solvent-accessible surface. I want to do this because it is my understanding that electrostatic potential mapping to a solvent-accessible surface is often more informative than to a solvent-excluded surface: http://www.poissonboltzmann.org/apbs/examples/visualization/apbs-electrosta… Can it be done? 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 3B62G Bethesda, MD 20892 Office 301-402-0095 Mobile 301-758-3559 http://bioinformatics.niaid.nih.gov (Within NIH) http://exon.niaid.nih.gov (Public) 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.

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Problem with Rainbow and "abnormal" PDB data
by Christian Schudoma 17 Sep '10

17 Sep '10

Dear Chimera-devs and community, I am "abusing" the 3D-rendering capabilities of Chimera to visualise 3D coordinates that do not actually represent molecular data. (Why do I do that? Because I love using Chimera for visualising molecular data and I needed a quick way to display (+ rotate/zoom) 3D data without hassle. I'm sure there are other solutions out there but I found it easier to convert my data to PDB than find a decent tool or code one myself.) I convert my xyz coordinates into PDB-format, using Hydrogen atoms and GLY as residue name (or, alternatively XXX - which wouldn't work either). I use the residue index (resSeq) to identify groups of points that belong together. This of course results in a complete nonsense-"protein" (with GLY-residues consisting of nothing but 100's of hydrogen atoms), which is nevertheless in syntactically correct (I hope) PDB format and both readable as well as displayable by Chimera (as a point cloud using wire-representation). Now to the problem I encountered: I would like to colour my "atoms" by their residue index. I can colour the individual "atoms" manually, using Select-operations or Ctrl-click and then the Color-menu. The Rainbow tool, however, does not work to colour my point cloud. It simply doesn't do anything. My question is, whether Rainbow performs some plausibility checking of the data (and if so, then whether it is necessary to do that? It would seem that Rainbow only needs to access either the residue, chain, or model indices to do what it's supposed to do, i.e. to assign colour)? Of course I am aware that my problem is kinda homemade and Rainbow works fine for normal PDB structures. I am also not saying that Chimera's buggy (although it seems to have a problem processing weird data in some situations (Rainbow) but not in others (manual colouring)). However, I'd like to understand why things don't work as expected ;) Cheers, Christian --- Christian Schudoma, M.Sc. Ph.D. Student Bioinformatics Group Max Planck Institute of Molecular Plant Physiology Am Muehlenberg 1 14476 Potsdam-Golm Germany phone: +49 (331) 567-8624 email: schudoma(a)mpimp-golm.mpg.de http://rloom.mpimp-golm.mpg.de

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find the region around a volume imported from 3V voxelator
by Fabian Glaser 15 Sep '10

15 Sep '10

Daer chimera team, I am interested in finding a channel in a toluene hydrogenase, and extracting all the residues / atoms surrounding this channel. To do that I calculated the channel itself using the 3V voxelator (http://3vee.molmovdb.org) which produces a volume object that can be imported to chimera. See for example the output page http://3vee.molmovdb.org/viewResults.php?jobid=10sep02.ee6, which provides the file channel-004.mrc.gz, which needs to be first unzipped. When uploaded to chimera the volume is very clear and nice. But I want to find the residues/ atoms that form the channel, one the pdb itself 3DHG.pdb.gz, although the select and zone features seem to not work with the volume object. Any idea how to do that? Thanks a lot, Fabian -- ------------------------------------------------------ Fabian Glaser, PhD Bioinformatics Knowledge Unit, The Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering Technion - Israel Institute of Technology Haifa 32000, ISRAEL E-mail: fglaser(a)technion.ac.il Tel: +972-4-8293701 Fax: +972-4-8225153

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transparent background
by Jon N. Rumbley 15 Sep '10

15 Sep '10

I have consistently used the transparent background in chimera in the past. I have upgraded my system to Windows 7 and installed both Chimera 1.4.1 and the daily build from 9/8/2010. When I try to set the transparency to true I get the following: Unable to turn on background transparency. Graphics hardware supports request, but can not switch while maintaining display data. Is there a simple solution for this? Thank you. Dr. Jon N. Rumbley Assistant Professor Dept. of Pharmacy Practice and Pharmaceutical Sciences University of Minnesota-Duluth 127 LSci 1110 Kirby Dr. Duluth, MN 55812 Phone: 218-726-6047 email: jrumbley(a)d.umn.edu

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Walking through a protein
by Daniel Gurnon 14 Sep '10

14 Sep '10

Hi everyone, Coot has an easily implemented way of "walking" through a peptide chain. It works like this: >From the drop down menu, choose "go to atom", pick the first residue. The view zooms to the first residue. Now hit the space bar, and the view smoothly advances to the next residue in the chain. Hold shift-space, and it smoothly moves back. Having an easy way to smoothly transition the view from one residue to the next would would be useful in Chimera. From my perspective it would be great for teaching, but I would think a simple way of walking along the backbone would be generally appreciated. I imagine this feature would be easy to construct with a Python script, maybe using the "fly" or "focus" commands. I'm not sure how to tie this to a keystroke, but an alternative is to give the function a toolbar button. If this capability doesn't already exist, could someone provide some advice on writing the script? I'm only just learning Python. Thanks for the help Dan -- ____________________________ Daniel Gurnon, Ph. D. Assistant Professor of Chemistry DePauw University Greencastle, IN 46135 p: 765-658-6279 e: danielgurnon(a)depauw.edu

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Joining fragments in a peptide bond
by Sujata 14 Sep '10

14 Sep '10

Hi All, I have two peptide fragments that I want to join with a peptide bond. So I move the 2nd fragment towards the C terminal of the 1st one and bring the C of 1st and N of 2nd manually closer such that the distance is 1.34 A. I combine the two PDB files into one and I have a peptide I want but in the process of bringing them closer, the angles around the peptide bond CA-C-O and C-O-N are not what they should be? My question is - is there a way to fix these angles while I am fixing the distance? What is the right way to join fragments in a peptide bond? Is there a cleaner way? Thank you. Appreciate your help. Sujata

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MD trajectory hbond analysis
by George Tzotzos 13 Sep '10

13 Sep '10

Hi everybody, I wonder is there's a way that Chimera produces hbond occupancy statistics from amber trajectory files. I can produce hbond information between a ligand and a receptor molecule frame by frame. As the ligand forms hbonds with different amino acid residues in the binding site during the trajectory, I'd like to work out which ones are the most frequently formed. Thanks in advance for your advice Best regards George

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Crash under Ubuntu Linux 10.4
by Mario Dejung 13 Sep '10

13 Sep '10

Hi All, I get a "Segmentation fault" message from Chimera... I tried to use all available version, so the 32bit and 64bit, and also the alpha versions... I can not reproduce the crash, it is not related to any command... Sometimes I can open a map an turn it or filter it a little bit and chimera crashes after 2 minutes... The other time it crashes after 10 seconds... At the moment I try to use the alpha 64bit version, is there a way to get more debug output? I run chimera under Ubuntu 10.4 Regards Mario

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zone command between proteins
by Francesco Pietra 13 Sep '10

13 Sep '10

Hello: How to map the residues at a given distance (<5A) between a protein and its 5-residues peptide ligand? I could only use the zone command for a non-standard residue in the peptide: sel protein & :non-standard_residuename_of_peptide All other peptide residues are standard residues. thanks francesco pietra

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Dielectric constant
by r charbel maroun 10 Sep '10

10 Sep '10

Dear Chimera users, What's the value of the dielectric constant used in the Energy minimize module ? What's the minimization algorithm used, Steepest descent or Conjugate gradients ? Is there any way to modify these values ? Greetings, -- R. Charbel MAROUN, PhD, HDR Neurobiologie et Pharmacologie Moléculaire Centre de Psychiatrie et de Neurosciences Broca-Sainte Anne (INSERM U894) 2ter rue d'Alésia 75014 Paris FRANCE Tél. +33 1 40 78 92 77 Fax +33 1 45 80 72 93 e-mail rmaroun(a)gmail.com charbel.maroun(a)inserm.fr

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