March 2009 - Chimera-users - RBVI Mailing Lists

Chimera does not always recognise atom name in PDB ATOM records
by Christian Schudoma 19 Mar '09

19 Mar '09

Hello Chimera-Users and -Devs, I encountered the following problem when trying to visualise the following purine molecule (Actually, I tried to do something more complex(*) but the same problem can be reproduced with this more simple example). For clarification, the first lines contain the column numbers. 1 2 3 4 5 6 7 123456789012345678901234567890123456789012345678901234567890123456789012345678 HETATM 1 N1 CKN A 1 -0.003 1.586 -3.371 0.00 0.00 N HETATM 2 C2 CKN A 1 1.016 1.511 -4.278 0.00 0.00 C HETATM 3 N3 CKN A 1 2.313 1.566 -3.865 0.00 0.00 N HETATM 4 C4 CKN A 1 2.576 1.683 -2.541 0.00 0.00 C HETATM 5 C5 CKN A 1 1.559 1.758 -1.597 0.00 0.00 C HETATM 6 C6 CKN A 1 0.224 1.717 -2.032 0.00 0.00 C HETATM 7 N7 CKN A 1 2.100 1.858 -0.373 0.00 0.00 N HETATM 8 C8 CKN A 1 3.434 1.842 -0.568 0.00 0.00 C HETATM 9 N9 CKN A 1 3.731 1.742 -1.876 0.00 0.00 N When I load a pdb file containing these coordinates into Chimera, I get 9 non-connected dots (obviously representing the atoms) which can neither be coloured by hetero-atom, nor by element. Note that the atom names are located in the appropriate columns, i.e. between columns 13 and 16, more specifically in columns 15 and 16. I noticed that in other pdb structures 2-character atom names are located in columns 14 and 15 and when I put my atom names there, Chimera displays the purine ring system which then can be coloured by hetero-atom/element. Now it is nice that this workaround fixes my problem, however, according to the pdb file format specification (columns 13-16 are reserved for the atom name), atom names located in columns 15 and 16 are valid(*) and as such should be processible by visualisation tools etc. The behaviour occurs with the latest daily build as well as some older versions I found on my hard disk... (*) The purine is part of a larger cytokinin. I stumbled upon the described behaviour while using the AddHydrogen function on the whole molecule, which lead to the replacement of the purine with a hydrogen. (**) Unless there are some additional rules regarding the placement of atom names shorter than 4 characters, in which case I apologise for bugging you with this. Any comments on this? Best regards, Christian Schudoma -- Christian Schudoma, M.Sc. Bioinformatics Group System Integration 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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Re: [Chimera-users] Making movies
by Elaine Meng 19 Mar '09

19 Mar '09

> Hi Elaine, > BD simulations is brownian dynamics. Well my file is in a PDB > format, and basically consist of a single complex, with heteroatoms > living from one active site to the other. If you open the file as a > pdb file you will realized the heteroatoms HOH are static. But I > want them to be able to move from the active site of one enzyme to > the other in the complex. > > I was thinking that I can put the word Model, between the complex, > and each heteroatom HOH, so as to make the file seem to have many > pdb files. Hi Neville, Yeah, I eventually realized you meant Brownian dynamics! But what matters for Chimera is the format rather than how the trajectory was generated. To use "MD Movie" to play/record the trajectory, your PDB format options are: (a) put each frame in a separate PDB file The file names must include frame numbers, and files for all intermediate frames must also be present. The files must not contain END records. (b) put all the frames in one PDB file, but bracket each with MODEL and ENDMDL, as is done for NMR ensembles in the Protein Databank, e.g. 1g1p. The MODEL numbers are interpreted as frame numbers and should start with 1 or 0 and increment by 1. Either way, atom names, residue names/numbers need to be the same between frames. ** In general, each frame should have the same number of atoms. However, for "weird" cases where lots of atoms stay in the same position (which if I understand correctly is what you have), we have made a special provision: if the coordinates supplied for a frame represent only a subset of the atoms in the preceding frame, it will be inferred that the remaining atoms are present but have the same coordinates as in the preceding frame. Changes are cumulated in the forward direction and based on all frames, even when frames are skipped during playback. All of the atoms must be in the first frame, of course. In your case, I guess that would include the proteins plus the starting locations of the heteroatoms. You might need to renumber the HOHs to keep their identities across the frames... looks like what you sent gives each position a different residue number. This information as well as how to play the trajectory and record it as a movie are in the MD Movie manual page (choose Help... User's Guide, click Tools tab, click link "MD Movie"). I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html

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Question about adding a sequence to a previous structural alignment...
by Sergio Garay 18 Mar '09

18 Mar '09

Hi all I've prepared an structural alignment of my 3 protein templates using MatchMaker/Match-Align tools. The question is: when I add my target sequence to the profile obtained in the step before, Does this procedure change my previous structural alignment?, or It just aligns the added sequence to my profile. The parameters that I used to add my target sequence are: Blosum-62, gap open, and gap extension penalties: 12 and 1 respectively. The second problem I have, its not related to chimera, but may be one of you can answer it. My target only has 29 % of identical residues with my templates, so Should I use a less stringent parameters to make my alignment? Any help would be appreciated. -- Dr. Sergio Garay 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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save image error in current daily build
by Ryan Pavlovicz 18 Mar '09

18 Mar '09

Hello, when trying to save an image with the current daily build of Chimera, i am finding that the program closes with the following error: X Error of failed request: BadAccess (attempt to access private resource denied) Major opcode of failed request: 129 (GLX) Minor opcode of failed request: 10 (X_GLXCopyContext) Serial number of failed request: 0 Current serial number in output stream: 15993 Just wanted to let you know. Thanks, ryan

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Re: [Chimera-users] merge mrc volumes
by Anindito Sen 18 Mar '09

18 Mar '09

Hi Tom Carsten actually just took away my question. Thanks Carsten! It will be really helpful to have such feature ! Thanks Andy Dr. Anindito Sen (Ph.D) Research Associate , Dept. of Biochemistry and Molecular Genetics University of Virginia Box 800733 Charlottesville, VA 22908 --- On Wed, 18/3/09, Tom Goddard <goddard(a)cgl.ucsf.edu> wrote: From: Tom Goddard <goddard(a)cgl.ucsf.edu> Subject: Re: [Chimera-users] merge mrc volumes To: carsten.mim(a)yale.edu Cc: chimera-users(a)cgl.ucsf.edu Date: Wednesday, 18 March, 2009, 5:43 AM Hi Carsten, There's no facility in Chimera to combine (add) maps into a single map though it has been requested by many people and I am anxious to add such a command. Tom carsten.mim(a)yale.edu wrote: > Hi there, > I constructed a model with different .mrc files. Now I want to save the model as > a merged *.mrc file, containing all previous files. > > Thanks > > Carsten > _______________________________________________ > Chimera-users mailing list > Chimera-users(a)cgl.ucsf.edu > http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users > _______________________________________________ Chimera-users mailing list Chimera-users(a)cgl.ucsf.edu http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users

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merge mrc volumes
by carsten.mim＠yale.edu 18 Mar '09

18 Mar '09

Hi there, I constructed a model with different .mrc files. Now I want to save the model as a merged *.mrc file, containing all previous files. Thanks Carsten

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Changing default element colors
by Dipl.-Ing. Thomas Mitterfellner 17 Mar '09

17 Mar '09

Hello! Can the default element colors be changed easily and if so, how? Thank you, Tom

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Chimera
by taritkumar MITRA 17 Mar '09

17 Mar '09

Dear Sir, I have just installed windows version of Chimera. I am a retired Chemist taken up Molecular Modeling as a hobby. I have some experience of using Spartan and Hyperchem. I would very much like to use the Chimera specially for studies Docking. Are theire any publication or books which will help me in learning to use Chimera. I f so I would like to buy it. Can you please help? With regards Tarit taritmitra(a)hotmail.com

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DICOM maps
by triffo＠rice.edu 17 Mar '09

17 Mar '09

anyone out there know the easiest way to get a DICOM map (typical format for medical CT/MRI data; volume density map; .dcm file extension) into chimera? Is there a translator out there that will reformat DICOM data into a chimera-friendly volume map? thanks, -Jeff

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heme (fe) containing enzyme
by Agus Setiawan 17 Mar '09

17 Mar '09

Hi, I'm a student of Pharmacy and I just learn about chimera.Actually, I want to run a docking using Autodock so I have to minimze the structure of macromolecule first. I choose Chimera to minimize the structure of macromolecule. However, there is an error because the Fe atom doesn't have GAFF"Unable to find GAFF type for #0:500.A@FE"I also have a problem with hydrogen at Histidin residu"no MMTK name for H at standard HIS"How can Isolve this problem?I'll be very thankful for your answers.Best Regards, Agus Lee.

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Chimera-users March 2009