- Chimera-users - RBVI Mailing Lists

crystal structure reconstruction
by rainy908＠yahoo.com 01 Oct '12

01 Oct '12

Hi, I am new to Chimera. I have a PDB of a protein comprising of a loop region that appears to have slight alpha-helical behavior when visualized in Pymol. However, I doubt that this region is actually structured, and that this alpha-helical behavior is actually an artifact from experimental conditions. To double-check the validity of this loop, I was broadly advised that "crystal structure reconstruction" can be performed in Chimera. I suspect this is either the 'molmap' or "Fit in Map" feature? Sincerely, Lili

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Error inizializing OpenGL
by Francesco Pietra 01 Oct '12

01 Oct '12

Hello: Following and upgrading of Debian GNU-Linux i386 testing (= wheezy) of my old PC francesco@deb32:~$ lspci | grep VGA 01:00.0 VGA compatible controller: NVIDIA Corporation NV11DDR [GeForce2 MX200] (rev b2) francesco@deb32:~$ with modern kernel francesco@deb32:~$ uname -r 3.2.0-3-686-pae francesco@deb32:~$ chimera francesco@deb32:~$ chimera --version chimera production version 1.6.1 (build 35849) 2012-03-13 22:24:07 UTC francesco@deb32:~$ does not start anymore: Error inizializing OpenGl. Couldn't configure togl widget. Before I go messing the system, may be I can get advice on where to put the hands. libgotl is not installed, but the same occurs with my GTX-680 amd64 system, where chimera works fine. Thanks francesco pietra

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Re: [Chimera-users] [chimera-dev] The style of Ribbon in alpha 1.7 version
by Elaine Meng 29 Sep '12

29 Sep '12

Hi Cheng, Actually the ribbon shape has not changed, but a bug in the lighting that made the ribbon look rounder than it really was has been fixed. (see release notes "general changes" http://www.cgl.ucsf.edu/chimera/docs/relnotes/snapshot.html#general ) You could use Ribbon Style Editor to make something that looks more similar to the old ribbon. I tried making a ribbon style shaped like a football (named "football") and combined that with a ribbon scaling with larger height for helix, sheet, and arrow base (named "fat"). I wasn't very careful drawing the football so you could probably make it better by drawing it more carefully. I attached a file you could use as your preferences file (although you would then lose your own earlier preferences), or you could text-edit to insert all of the lines in the attached file *except* the top and bottom lines into your existing preferences file. Either way, you should save a copy of your existing preferences file first so you don't lose your settings. Or, you could just make a fatter scaling and football-shaped cross section (style) in Ribbon Style Editor yourself, without using the attached file. If you do use the attached file, you could apply everything with commands: ribscale fat ribrepr football Chimera-dev is for programming questions - I'll CC the chimera-users email address since that is more appropriate for this issue, and others on the list may be interested. 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 On Sep 29, 2012, at 3:17 PM, Cheng Wang wrote: > Dear Chimera Team, > Hi. > The ribbon style in 1.6 version is a little round for helix, while it is really flat in 1.7 version. I want to use v1.7 since several commands are really good for movie making eg. format option and transparency. However the ribbon style for helix is not as nice as it in 1.6. I am wondering how could I change the style of ribbon in 1.7 to be the same as in 1.6 since the ribbon style seams the same in the panel for both versions. > Many thanks. > Best, > Cheng

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Specifying colour of surface cap when surface coloured by electrostatic potential
by Ashley Pike 28 Sep '12

28 Sep '12

Hi - Can't find answer to this question in manual. Is it possible to assign a uniform solid colour to a surface cap when the (clipped) surface is coloured by electrostatic potential (using external .dx file)? I know such capping can be done when the surface is coloured by some other attribute but have not found a way to specify in the above case. Any hints gratefully received. Many thanks, Ashley -- Dr. Ashley Pike Membrane Protein Crystallography | Structural Genomics Consortium | University of Oxford

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Silhouette color change
by vamsee 27 Sep '12

27 Sep '12

Hi Elaine, I need to change the silhouette color of individual models and if possible for individual representations (ribbon, surface or atoms). Is there a command line option that I could use? (maybe set?) Thanks in advance Vamsee

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Measuring angles between atoms pairs
by Yasser Almeida Hernandez 26 Sep '12

26 Sep '12

Dear Chimerians... I'm running an analysis about H-bonds geometries in several models. I need to measure the distance of a H-bond and the angle formed with a third atom bonded to one of the H-bond atoms. How could I do that in a python IDLE/script? In a more general way, how could I measure the angle between three atoms linked by a bond o pseudobond? Thanks in advance Yasser -- Yasser Almeida Hernández, BSc. Center of Molecular Immunology (CIM) Tumor Biology Department 216 St.& 15th Ave, Siboney, Playa P.O.Box 16040, Havana 11600 CUBA Phone: (+53-7) 214-3178 almeida(a)cim.sld.cu<mailto:almeida@cim.sld.cu>

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E. coli cells
by Victor Padilla-Sanchez 24 Sep '12

24 Sep '12

Dear UCSF Chimera, Could you tell me where to find chimera maps of E. coli cell(s) ? Or could you send me some maps ? Thank you very much Victor Padilla-Sanchez

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drawing circles
by Bala subramanian 24 Sep '12

24 Sep '12

Friends, I want to draw concentric circles of increasing sizes around the protein. To achieve this, i used the 'define plane' option to draw disk choosing I three reference atoms and drew the disks of increasing sizes and choose two different color for the inner and outer disk. Since the reference atoms are the same. If i change the color of the bigger disk, i get a weird appearance of the inner disk. I dnt know how to resolve this problem. I would like to know if i can do something like making the disk transparent/removing the fill color of the disk. thanks, Bala -- C. Balasubramanian

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"No MMTK name for atom "H" in standard residue "G" "
by Nikolay Igorovich Rodionov 22 Sep '12

22 Sep '12

Hi could someone help me with this error: No MMTK name for atom "H" in standard residue "G" I get this error when running the minimize structure function. Does anyone know a work around or how I can fix the problem? Nikolay Rodionov Nikolay Rodionov| MBA Candidate & B.S. Bioengineering 2015 Martin J. Whitman School of Management & L.C. Smith College of Engineering at Syracuse University Syracuse, New York 13244 Phone: 281.301.9401| Email: Nirodion(a)syr.edu

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Potential Energy Calculations
by Nikolay Igorovich Rodionov 22 Sep '12

22 Sep '12

Hi all, I was wondering the there is a tool in chimera that can find the net interaction potential energy between models, something like Lennard Jones Potential. Specifically, I need to measure the interaction potential between a protein and water in a solvated system. Thanks! Nikolay Rodionov Nikolay Rodionov| MBA Candidate & B.S. Bioengineering 2015 Martin J. Whitman School of Management & L.C. Smith College of Engineering at Syracuse University Syracuse, New York 13244 Phone: 281.301.9401| Email: Nirodion(a)syr.edu

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Calculation of SASA with probe size of 0.8Å
by Amy Davenport 21 Sep '12

21 Sep '12

Hi all, I am trying to calculate the solvent accessible surface area of my protein. I would like to use a probe radius of 0.8Å to do so, but do not see a way to alter the probe size past what the selectable values are in the structools menu. Additionally, I need all atoms to be included, which means hydrogens as well. Any help would be greatly appreciated. Thank you, Amy Davenport Migliori UCSD

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Estimated RMSD after using Modeller feature
by Claudia Fernandes 21 Sep '12

21 Sep '12

I used Modeller function in Chimera to make some comparative models and then used the estimated RMSD function. I used two querys for different modeling jobs. The original query that was similar to the target I choose and a query that has an extra 26 N-terminus aminoacids than the target I choose. Using the same tamplate, shouldn't the estimated RMSD be the same for the original query and the longer query (with the extra Nterminus aminoacids)? As it isn't, how is it being calculated? I found that the calculation was carried out with TSVMod, but I couldn't find anything about how i does it. Any help would be welcome. Regards, Cláudia Fernandes

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Modeller-Chimera interface
by James Valdes 21 Sep '12

21 Sep '12

Hello Chimera, I'm using the Modeller interface via Chimera and I was wondering if the models produced takes into account multiple templates (e.g., selecting all) from a multiple alignment produced by MAFFT (http://mafft.cbrc.jp/alignment/software/) I appreciate any insight you may provide. Cheers, James Jason Valdés, Ph.D.

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arrow heads for pipes and planks
by Evan Kantrowitz 20 Sep '12

20 Sep '12

Hi, Probably a dumb question, but I cannot figure out how to show arrow heads on pipes and planks. I found this info Show arrow on helix and Show arrow on strand (both default true) place arrowheads on the C-terminal ends of secondary structure elements to indicate N→C directionality. These are not on the pipes and planks tool. What is the format on the command line to use this commands I tried Show arrow on helix Show arrow on helix true Thanks Evan ------------------------------------------------------------------- Evan R. Kantrowitz, Ph.D evan.kantrowitz(a)bc.edu<mailto:evan.kantrowitz@bc.edu> Boston College Tel. 617-552-4558 Department of Chemistry FAX 617-552-2705 Merkert Chemistry Center, Rm 239 www2.bc.edu/~kantrow<http://www2.bc.edu/~kantrow> Chestnut Hill, MA 02467 -------------------------------------------------------------------

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saving a rotated map
by Filip Van Petegem 20 Sep '12

20 Sep '12

Dear chimera users, I have a problem with saving a cryoEM map after rotating/translating it. I've used the 'fit in map' option to superpose 2 maps (in ccp4 format) This seems to work fine, but when I save the reoriented map (in any of the available formats), and try to open it, it is back to the original position. Is there any way to save the reoriented map file? Best regards, Filip Van Petegem -- Filip Van Petegem, PhD Associate Professor The University of British Columbia Dept. of Biochemistry and Molecular Biology 2350 Health Sciences Mall - Rm 2.356 Vancouver, V6T 1Z3 phone: +1 604 827 4267 email: filip.vanpetegem(a)gmail.com http://crg.ubc.ca/VanPetegem/

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solvation box transformed
by Visvaldas K. 20 Sep '12

20 Sep '12

Dear Users, I have some difficulties with reference frames when solvating a protein. The essence of my problem as follows. Chimera solvates a box using _untransformed_ coordinates, but if I try to write out the inpcrd/prmtop, it writes out the _transformed_ coordinates, thus the box planes become no longer parallel to xyz axes, which does not allow to transfer the inpcrd coordinates to another program (NAMD). Of course, I could try a workaround by creating the protein and re-saving it before solvation, and then solvating it while avoiding any mouse movement,or using ambertool cooman line, but maybe there is another solution, or perhaps an "untransformed" button could be implemented in the prmtop tool? Sincerely, Vis

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Chimera running on a remote computer over ssh >>>> use virtualgl to avoid graphics problems
by Dieter Blaas 19 Sep '12

19 Sep '12

Those who encountered lots of problems with the graphics when running chimera remotely for example you receive error messages like this one: X Error of failed request: GLXBadContextTag Major opcode of failed request: 153 (GLX) Minor opcode of failed request: 5 (X_GLXMakeCurrent) Serial number of failed request: 1352 Current serial number in output stream: 1352 might be interested in the following solution: 1) install VirtualGL (http://www.virtualgl.org/) on both PCs 2) outcomment the indicated lines in the 'chimera' startup script 3) connect to the server by using 'vglconnect' 4) start chimera on the server with 'vglrun chimera' that's it! if [ -z "$nogui" ] then case "`uname -s`" in Linux) # preload our C++ runtime to avoid # ATI graphics driver bug # LD_PRELOAD=libotf.so <<<<<<<<< # export LD_PRELOAD <<<<<<<<< if test -e "$CHIMERA/bin/python2.7" then python="$CHIMERA/bin/python2.7" else in those cases where chimera works without this trick you might still see a substancial improvement in transmission speed! Best, Dieter -- ------------------------------------------------------------------------ Dieter Blaas, Max F. Perutz Laboratories Medical University of Vienna, Inst. Med. Biochem., Vienna Biocenter (VBC), Dr. Bohr Gasse 9/3, A-1030 Vienna, Austria, Tel: 0043 1 4277 61630, Fax: 0043 1 4277 9616, e-mail: dieter.blaas(a)meduniwien.ac.at ------------------------------------------------------------------------

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Re: [Chimera-users] chimera utility help
by Elaine Meng 17 Sep '12

17 Sep '12

Dear Sotirios, You would use Join Models option "C-N peptide bond" as described in these instructions: <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/editing/editing.ht…> "C-N peptide bond - specialized case of joining two peptides. The N-terminal N of one peptide and the C-terminal (carbonyl or carboxyl) C of the other should be selected. Each selected atom must be bonded to only one carbon; however, it may also be bonded to hydrogen and/or OXT, and if so, these atoms will be replaced as appropriate by the new peptide bond." If you do not see that option, maybe you have an older version of Chimera and should upgrade to a newer version. If you do see that option and you have followed the instructions as above but are still not able to apply, please save a session file and use menu "Help... Report a Bug" and attach the session file to the bugreport. I just tried it on two example proteins and seemed OK, but maybe there is something different about your structure. Thanks! 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 Sep 17, 2012, at 9:10 AM, Sotirios Katsamakas wrote: > Dear Elaine C. Meng, > I followed your suggestion and I created a separate side chain of the 25 amino acids with specified phi and psi values for its residues. But I am still not able to Join Models, through the homonymous section. I am selecting the C terminus of the constructed side chain (#0:25@C) and the N terminus of the protein (#1:26@N) respectively, but when I go to the panel the apply button stays inactive. I am sure it must be something obvious but it eludes me. Thank you in advance and I am looking forward in hearing from you. > > Best Regards, > Sotirios Katsamakas.

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Difference between atoms' coordinates on screen and in a PDB file
by Mateusz Dobrychłop 14 Sep '12

14 Sep '12

Hello, I load 3 protein models into Chimera and enter several "move" commands. The structures change their positions. Then, I save them as a PDB file, and immediately open the PDB file. The structures are not overlapping (screenshot: http://i.imgur.com/gtGBN.png ). Why does it work like this and what can I do to obtain accurate coordinates on my screen without re-opening the model (after I finish my sequence of translations)? Mateusz

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Denaturing a protein
by vamsee 14 Sep '12

14 Sep '12

Hi Elaine, Thanks for the answer for the previous question. I am back with one more :) Is there a way to completely denature a protein in Chimera? The idea is to completely unfold a particular protein (for ex: chemical denaturation GdHCl/Urea or thermal denaturation) to its primary structure. Also can this be modeled in such a way that we can extract thermodynamic parameters from the modeling? I do understand this sounds a lot like a Molecular Dynamics simulation but maybe there is a way in Chimera? Thanks again Vamsee

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sphgen format
by Brian Fochtman 13 Sep '12

13 Sep '12

Hello, I read in the release notes for version 1.6 that Chimera is now able to input files in the dock .sph format. Thank you for this feature, it will be very helpful. Unfortunately I am having some trouble using it. (File -> Open -> file.sph) declares a syntax error for the following file (I've only included the beginning of the file because the output says the synax error is on line 2). Is there another method to read in these files? Thank you, Brian Fochtman cluster 1 number of spheres in cluster 72 1 20.51900 -17.55400 15.86300 0.700 1 2 21.04300 -18.55700 16.07400 0.700 2 3 22.17700 -17.60500 16.24100 0.700 3 4 22.17500 -17.84200 15.30900 0.700 4 5 21.41300 -20.08800 15.15700 0.700 5 6 20.64000 -20.83100 16.58800 0.700 6 7 21.63200 -18.65500 14.15300 0.700 7 8 23.13800 -16.98900 16.54500 0.700 8 9 21.18800 -21.21200 14.71200 0.700 9 10 17.88800 -26.45300 19.89900 0.700 10 11 21.83900 -17.33000 12.81300 0.700 11 12 21.28600 -20.42100 13.28900 0.700 12 13 23.77100 -15.65400 16.91100 0.700 13 14 21.15100 -21.76500 13.92000 0.700 14 15 21.38500 -19.46300 12.20200 0.700 15 16 20.39500 -21.75600 13.41100 0.700 16

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Gromac .xtc format
by Eric Pettersen 13 Sep '12

13 Sep '12

Hi, For you Chimera/Gromacs users out there, the current daily build allows you to use .xtc format coordinates now as an alternative to .trr . --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu

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chimera utility help
by Sotirios Katsamakas 13 Sep '12

13 Sep '12

Dear sir or madam, I am a recent user of the chimera software on Linux-Ubuntu (11.10) operating system and I confronted a dead end on the following issue. I reconstructed a missing side chain of 25 amino acids in a PDB file but I cant seem to find how to set the secondary structure and so on for these 25 residues. So they are stuck in a linear formation externaly from my protein. For your consideration I am attaching also the PDB file. Thank you in advance and looking forward in hearing from you regarding my problem. Best Regards, Sotirios Katsamakas

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Re: [Chimera-users] Match->Align command line option?
by Eric Pettersen 12 Sep '12

12 Sep '12

On Sep 12, 2012, at 11:16 AM, Chetanya Pandya wrote: > Hello, > > I want to superimpose multiple structure sets and get the corresponding multiple sequence alignments using Chimera. I've been using the Match->Align option from the Tools menu. Now, I want to automate the process using the Python interface. > > Unfortunately, I'm unable to find a command line option which does this. Can you help me out with this? Hi Chetanya, It's a little ambiguous if you are asking about a command version of Match->Align, or how to call it from Python. The issue is moot though since there currently is no command version of Match->Align, so you have to call it from Python! I don't know how familiar you are with Python or programming with Python, but the Chimera Programmer's Guide has some info to help. http://www.cgl.ucsf.edu/chimera/docs/ProgrammersGuide/index.html If you don't know Python at all, follow the link in the Guide to the Python Tutorial and work through that, or at least the first few sections of that. Then for some Chimera-specific info, look at some of the Examples and the "basic primer" linked on the page. Assuming you've written a script that has gotten to the stage where the structures are already open and superimposed, here's the info you'll need to use the Match->Align API: 1) Getting the list of open molecules: from chimera import openModels, Molecule mols = openModels.list(modelTypes=[Molecule]) 2) Getting the list of chains to use. This example code assumes they're chain A: chains = [m.sequence('A') for m in mols] 3) Call Match->Align to create the alignment. from StructSeqAlign import makeAlignment mav = makeAlignment(chains) Note that the makeAlignment call will only return the Multalign Viewer instance starting with tomorrow's daily build (i.e. I made that change today!). Also, the makeAlignment call has a lot of optional arguments to change the parameters used in computing the alignment (e.g. cutoff, iteration, reference chain). Look at <your Chimera>/share/StructSeqAlign/__init__.py to see what the options are if you need to change the default behavior. (On a Mac, "<your Chimera>" is Chimera.app/Contents/Resources). 4) Save the alignment to a FASTA format file (named "x.fa") and Quit the MAV instance: f = open("x.fa", "w") from MultAlignViewer.formatters.saveFASTA import save save(f, mav, mav.seqs, mav.fileMarkups) f.close() mav.Quit() I hope this helps. Since this is pretty Python-intensive, I set followups to go to the chimera-dev mailing list rather than chimera-users. --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu

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Visualization of protein aqueous solution
by Nikolay Igorovich Rodionov 10 Sep '12

10 Sep '12

Hi all, Could anyone tell me how I could solvate my protein in a solution of a specific molarity solution with both water molecules and Na+ Cl- ions. I have no trouble adding the water molecules, but I am not sure how to go about adding the ions into the visualization. I've tried using add-ion but I haven't had good results. Are there any other options? This is for purely visual purposes, I'm creating a conceptual image, so I don't need the system to be 100% accurate or capable of conducting calculations. Much Thanks! Nikolay Rodionov

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