- Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] per-model clipping plane
by Thomas Goddard 26 Mar '07

26 Mar '07

Hi Jean-Francois, There is not yet a command specifically to move per-model clip planes. But you can do it using the "savepos" and "reset" commands. These save and restore the positions of all models and the per-model clip plane positions (Chimera 1.2352 and newer). For example, you can save an initial position with command savepos p1 then move a per-model clip plane with the mouse to a new position and save that savepos p2 then to smoothly go from position p1 to p2 over 100 frames use reset p1 reset p2 100 The named positions are saved in Chimera session files. Saving of per-model clip positions when you use savepos was added very recently (March 1, 2007) so you need Chimera snapshot version 1.2352 or newer. Formerly just the model orientations were remembered. Tom jean-francois menetret wrote: > > Hi Thomas, > > is it possible to move the per-model clipping plane using a > movie-related command ? > > Jean-Francois > >

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need help to run chimera 1.2304-linux.exe
by 김소연 26 Mar '07

26 Mar '07

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saving image as stereo pair
by Boaz Shaanan 25 Mar '07

25 Mar '07

Hi, It seems to me as if the stereo pair produced when I select 'stereo pair' in save image is crossed-eye stereo (not wall-eye), or is my brain fooling me ? I certainly see a left-handed alpha helix, residues in the front going to the back and D-amino acids when I use my stereoviewer. Please advise. Thanks. Boaz Boaz Shaanan, Ph.D. Associate Professor Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Phone: 972-8-647-2220 ; Fax: 646-1710 Skype: boaz.shaanan‎

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Counting atoms within density map contour
by Tom Goddard 23 Mar '07

23 Mar '07

Hi Gary, You asked yesterday whether it is possible to count the atoms lying outside the contour surface of a EM map after fitting. This can be done although it currently requires a few steps. Here's how. 1) fit the atomic model into the map as desired. 2) Use menu entry Tools / Volume Data / Values at Atom Positions, choose the molecule and map and press the Histogram button. This shows a histogram of the map values interpolated at the atom positions. 3) Press the "Select" tab on the Render / Select by Attribute dialog and choose Attribute "value_mymap.xxx", move the rightmost green bar on the histogram to match the contour level, then press the Apply button. This procedure selects the atoms at lower density levels than the map contour level and you can see the number of atoms selected in the lower right corner of the main graphics window. You can press the up arrow key a few times to select all atoms in the molecule to see the total number of atoms. I show a picture below fitting 1i84.pdb into myosin.map where 2727 of 16070 atoms lie outside the contour surface. I colored the selected atoms outside the contour blue in the picture. Tom

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osx headers
by Randy Heiland 23 Mar '07

23 Mar '07

Out of curiosity, what is different in the ppc and intel headers for 1.2349? I see that both are available on the Source download page. -Randy

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installing chimera over an older chimera install?
by Sabuj Pattanayek 23 Mar '07

23 Mar '07

Hi, On *nix is it safe to install a newer version of chimera over a previous installation? Will this break something in the newer installation? The reason why I ask is the trouble of maintaining externally installed plugins. We could make a wrapper for the .exe unzipsfx install and re-build symlinks to an external directory of chimera plugins in the share directory, but this seems like too much trouble especially if just installing over an old installation should just "work". Thanks, Sabuj

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Two transparent models and memory leaks
by Thomas Goddard 22 Mar '07

22 Mar '07

C Akey report problems with display of two transparent models and excessive memory use and crashes when saving images. ------------ Tom- Sorry to bother you but I am having serious problems with Chimera while trying to make figures for a paper. After you fixed the sessions number problem, so that they are retained in the same numbered slots from one session to the next, I found that my most recent sessions made with this version, would not work properly when I wanted two different displayed volumes to have transparencies different from 1. This worked in earlier versions and then I started over with a new session, imported everything and it is working again. Maddening. If you have a ribbon within a volume and try to vary the transparency, it almost disappears instead of having a gradual blending effect (see attached figures A,D panels). I am using a PC under XP with 1Gb mem and 512 GB graphics card. I have checked and memory is not the problem. {However, if you quit a session then open another session, Chimera does not give the memory back to the system, so your memory use soars, YOU MUST QUIT BEFORE OPENING A NEW SESSION.} Here is another killer bug: When you record an image full screen, about half the time you get a fatal error in pythonw.exe, it wants you to contact Microsoft and then Chimera crashes losing everything. The error from chimera reads "failed 1073741891" but there is no chance to report the bug. So after battling to get to the point of recording images, the program quits on me about half the time. By the way, when Chimera is shown full screen on our new Linux machine, it doesn't clearly show all the icons on the left hand side of the screen, they are partly occluded. sorry about the bugs but its starting to get to me. cheers C Akey

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New Chimera molecular surface code
by Tom Goddard 22 Mar '07

22 Mar '07

Miguel Ortiz Lombardia asks when Chimera will be able to compute solvent accessible surfaces. -------- Original Message -------- Hi Tom, I would like to know if there has been any advancement in changing the surfaces code. I know you had plans to write your own so that chimera would not rely on msms, and I am very interested in this development because it would allow the use of solvent accessible surfaces apart from molecular surfaces. The former are more appropriate, among other questions, to map electrostatic potential maps (less local effects). I would be happy to test around, if you need testers. Unfortunately my programming skills are quite minimal. But I'll be patient anyway ;-) Thanks to all of you for this great tool! Cheers, Miguel

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MODELLER interface
by Elaine Meng 21 Mar '07

21 Mar '07

Hi Stefano, No arguments here - we have talked about it and I've expressed a need for it for years. The problem is that there are many other features that seem to be at least as high priority, and limited time and manpower available. To name only a few of the things in progress: energy minimization, morphing, interaction with dendrograms (along with sequence alignments), more display preferences, more animation commands, and producing ray-traced images. There is a "model loops" tool that interfaces with MODELLER, but it only produces alternate conformations of loops that are already in a structure. That was implemented because people in the MODELLER (Sali) group here wanted it the most, and it needs work - e.g. currently there is no convenient way to merge a chosen loop conformation back into the structure. Nevertheless, this is another important item and I will share your message to help ensure it does not fall off "the list." I imagine any validation tools would be farther down on the list than the interface for comparative modeling, although we do already have a tool that finds clashes and close contacts. Elaine On Mar 20, 2007, at 10:05 PM, Stefano Ciurli wrote: > Elaine, > > following our discussion on Chimera and DelPhi, and these recent > mails on modeling, don't you think that it would be nice to > interface Chimera to Modeller, as the latter one is one of the most > used software to do homolog modeling? The interface could be a sort > of way to funnel into Modeller the alignment and the structure of > the template(s) for Modeller to use and then read back into Chimera > the results of the modeling, with tools to establish the quality of > the model itself (I am thinking of Prosa, Procheck or WHATIF) > > Regards > Stefano > -- > ____________________________________________ > > Stefano Ciurli > Professor of Chemistry > Laboratory of Bioinorganic Chemistry > Department of Agro-Environmental Science and Technology > University of Bologna > Viale Giuseppe Fanin, 40 > I-40127 Bologna > Italy > Phone: +39-051-209-6204 > Fax: +39-051-209-6203 > > http://www.cerm.unifi.it > http://www.isa.unibo.it/ISA/ > > "Fatti non foste a viver come bruti, > ma per seguir virtute e canoscenza" > Dante Alighieri - Inferno - Canto XXVI > > "Ihr seid bestimmt, nicht Tieren gleich zu leben, > Nein, Tugend zu erringen und Erkenntnis" > "Ye were not form'd to live the life of brutes, > But virtue to pursue and knowledge high"

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sequence & structure in Chimera
by Elaine Meng 20 Mar '07

20 Mar '07

Hi Abhijit, If I understand correctly, there were two questions here: > One more question is it possible to take a protein sequence of a gene, > part of which is cloned, crystallized and 3d structure is available, > and superimposes the protein sequence with the reported crystal > structure? Or how can you model a protein sequence to generate a > putative structure, for the part that hasn’t been crystallized so far, In Chimera, (1) can you associate a structure with a sequence that is read in from a separate file? short answer: yes, if that sequence is in an alignment (2) can you do comparative modeling (create a 3D model of an unknown structure starting from a known structure that is thought to be similar)? short answer: no, except simplistic replacement of a few side chains with the command "swapaa" I'll start with #2: Chimera does not do comparative modeling or threading different sequences on a known structure. Besides the approaches mentioned by Eric (getting a model from MODBASE or using the MODELLER program to make the model yourself), listed below are several web servers that might be useful. I believe the first two replace side chains while the others perform more complete modeling (can handle insertions/deletions and adjust the backbone). It's been a while since I used any of these, however, so you should read any author-provided information. - SCWRL server http://www1.jcsg.org/scripts/prod/scwrl/serve.cgi - Maxsprout server http://www.ebi.ac.uk/maxsprout/ - ModWeb server (requires registration) http://alto.compbio.ucsf.edu/modweb-cgi/main.cgi - RAPPER server (registration encouraged) http://mordred.bioc.cam.ac.uk/~rapper/ - PSIPRED server http://bioinf.cs.ucl.ac.uk/psipred/ - Swiss-Model server http://swissmodel.expasy.org//SWISS-MODEL.html Now question #1. You already saw the Sequence tool, which shows the exact sequence of any peptide or nucleotide chains in structures open in Chimera. However, you might want to read in a sequence from a separate file and associate it with the structure to allow the same kinds of crosstalk (a selection on the sequence selects the structure and vice versa). You can do that, if you have an alignment of that sequence with one or more additional sequences. These other sequences don't need to have any structures, and your sequence of interest does not have to match the structure exactly to associate with it (often there are point mutations, or the sequence is for a close homolog of the structure, or the structure is missing a few residues here and there, or is only one domain from the whole sequence). Here's a list of the sequence alignment formats that can be read (you can just use File... Open in the Chimera menu): http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/filetypes.html#alignment and the "Sequence-Structure Association" section in this page may be useful: http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/ multalignviewer/framemav.html I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab 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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