October 2015 - Chimera-users - RBVI Mailing Lists

Chimera crashes when I try to open a .gro file
by Raag Saluja 09 Oct '15

09 Oct '15

Hi! Chimera crashes when I try to open a .gro file (created through GROMACS). I wanted to open the .gro file and then superimpose it on a .pdb file. Can you please guide? Thank you! Regards, Raag

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display a coordinate system in view
by Byrd, Robert A. (NIH/NCI) [E] 09 Oct '15

09 Oct '15

I would like to represent a xyz coordinate system by the unit vectors on the display with a molecule. Ideally, for a two domain protein, I would like to have two coordinate systems, one for each domain. In an ensemble of structures where one domain changes orientation with respect to the other, one coordinate system would move to the new position. It would be nice to then morph from one position to the next. This is straightforward with a set of structures and the morph utility in CHIMERA. The ability to add the two coordinate systems to the display, and have them ‘move’ or morph from one position to the other, would highlight the geometrical averaging that takes place. Is this possible in CHIMERA? Thanks Andy Byrd

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on command scripts related to movie by chimera
by Smith Liu 09 Oct '15

09 Oct '15

Dear All, I want to learn several commands on chimera movie preparation. Only read the on-line material I find I still meet some difficulty. Suppose I have 2 scripts， each for 1 movie. Will you please tell me by which command in the script I can link the 2 scripts so that the 2 movie will change into 1 movie? Suppose in Chimera I have opened 2 PDB files. Will you please show me the commands to view the structure in the first PDB, then change to view the structure of the second PDB （different from the purpose of morph）? And how about if then we see the 2 structures together, all in a single movie? Best regards. Smith

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3D-visualization of protein chain and mutation
by Elaine Meng 09 Oct '15

09 Oct '15

> From: "Coci, Emanuele" <Emanuele.Coci(a)akh-celle.de<mailto:Emanuele.Coci@akh-celle.de>> > Date: Friday, October 2, 2015 at 8:54 AM > Subject: 3D-visualization of protein chain > > Deat Chimera team, > my name is Emanuele Coci, MD PhD. > > I would kindly ask you for help about Chimera software in solving the following technical issue. I want to visualize the 3D-structure of a mutated protein chain. > > Which of the chimera tools is more indicated to visualize the 3D structure? > Is the toll open source? > Which software do I need to download the tool on my PC : JAVA, …? > > Best regards and many thanks in advance? > Emanuele Coci Dear Emanuele Coci, Chimera is a free download for any noncommercial use (research, education, …) and is available for Windows, Mac, and Linux. You should not have to download any other software to use it. All you need is a reasonably modern computer. See Chimera homepage and download links: <http://www.rbvi.ucsf.edu/chimera/index.html> <http://www.rbvi.ucsf.edu/chimera/download.html> I’ve CC’d chimera-users(a)cgl.ucsf.edu — that is the proper address for user questions. There are many possible styles of displaying a protein, and you have to use your own judgement and artistic taste to decide which style is best for what you want to see for yourself or show to others. There are several step-by-step tutorials for learning how to use Chimera, including “getting started” for beginners and some example image tutorials: <http://www.rbvi.ucsf.edu/Outreach/Tutorials/GettingStarted.html> <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/frametut.html> For showing a mutation, the first thing you could do is just show the location of that amino acid on the structure (without mutating it), for example coloring it differently than the rest of the structure. It may be helpful to show the sequence of the protein so that you can identify the correct position (Chimera menu: Favorites… Sequence). You can choose a residue with the mouse in the sequence window, which will automatically select-highlight it in the structure. Secondly, you could try “mutating” that residue computationally. This could be done with the Rotamers tool (in menu under Tools… Structure Editing) or the “swapaa” command. There is an example of using the Rotamers tool in the “Structure Analysis and Comparison” tutorial: <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/tutorials/squalene.html> <https://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/rotamers/rotamer…> <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/swapaa.html> However, Chimera will not predict any larger-scale changes in the structure from the mutation or calculate changes in stability or affinity. It will only change the sidechain and not move anything else. You can use Rotamers to analyze the H-bonds and clashes (bad contacts) of different conformations of the sidechain, which may allow you to hypothesize whether the mutation would be disruptive to the stability or interactions of the protein. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco

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Newlines in labelopt string
by Repic Matej 07 Oct '15

07 Oct '15

Hi everyone, I have pretty long atom labels and it would be nice if I could split them with newlines. I set labels with labelopt info %(name)s %(ee).2f %(ea).2f %(er).2f # what I have C3 0.41 0.22 0.14 # what I want C3 0.41 0.22 0.14 The obvious \n does not work. Any ideas? Thank you, ------------------------------------------------------ Dr. Matej Repic Ecole Polytechnique Fédérale de Lausanne Laboratory of Computational Chemistry and Biochemistry SB - ISIC LCBC BCH 4108 CH - 1015 Lausanne ------------------------------------------------------

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Joining Models + Avoiding Steric Clashes
by Carlos Gonzalez Oliver, Mr 06 Oct '15

06 Oct '15

Dear Chimera, I have been trying to use Join Models to make a C-N bond between the globular domain of a protein and a region of it (a C-terminal tail) whose structure I simulated using MD. However, when I do the joining with Join Models C-N bond option, I get some serious steric clashes. I have tried to resolve them by hand by adjusting the bond's torsion and angles but it is too complicated. Other than trying to use other software to minimize clashes, I think I might have to use a brute force method and try a bunch of the structures my MD generated until one of them works. So what I am trying to do now is write a script to do the model joining automatically with many different structures that I generated, and return the one with the least number of clashes. But I haven't been able to find a command line equivalent of the Join Models window.. I was wondering if you know if such a command exists, if not what combination of commands would work? (for repositioning the models and forming the bond) Thanks! -- Carlos G. Oliver M.Sc. Student Vogel Lab Department of Biology McGill University Montréal, QC, Canada

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Problem on Nucleic Acid Ribbon
by Francesco Papi 06 Oct '15

06 Oct '15

Good morning, I'm working on a DNA X-ray structure. The problem I have observed is that the terminal nucleotide of the DNA sequence is excluded from the backbone ribbon, in other terms the backbone ribbon is shown and it is ok, but it is made of all the residues except the terminal one, which is linked to the ribbon by a long phosphodiester bond (see the attached image). Moreover, if I put the representation "Show side (sugar/base)", from the option "Nucleotides", to be "fill/slab", the terminal residue still features an "Atom & Bonds" style. The PDB file seems to be ok, as confirmed by a colleague. Do you how to solve this problem? Best regards Francesco Papi

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solid rendering color voxel by voxel?
by Oliver Clarke 06 Oct '15

06 Oct '15

Hi all, I don’t think this is possible right now, but i just wanted to check and maybe put in a request for addition to Chimera 2 at some point if you think it would be a useful feature. I like generating looping maximum intensity projection movies like the following (using EMDB 2807 as an example): https://www.dropbox.com/s/elt2f5so6azvvhk/emdb2807_example1.mp4?dl=0 <https://www.dropbox.com/s/elt2f5so6azvvhk/emdb2807_example1.mp4?dl=0> https://www.dropbox.com/s/julh586sc9yxl7g/emdb2807_example2.mp4?dl=0 <https://www.dropbox.com/s/julh586sc9yxl7g/emdb2807_example2.mp4?dl=0> Command used to generate representation: #Makes a pseudoprojection style view of the given volume #Usage: volume_project #map_id alias ^volume_project background solid black; volume $1 step 1 sdlevel 0,0 color white sdlevel 20,1 color white style solid projectionMode 3d maximumIntensityProjection true btCorrection true linearInterpolation true; unset depthCue I feel like even at small sizes, this gives a good idea of the overall quality of the electron density, in both mobile and well-ordered regions, due to the non-thresholded nature of the representation. It seems to me that this would be a natural fit for Resmap coloring to color a map by local resolution, as one of the issues I have with the application of Resmap in surface representation is that if you contour the map at a sufficiently low threshold to see the less well ordered parts of the structure, you can’t see the voxels that have the best local resolution (necessitating slabbing of the map). This would also be handy for using Color Zone to color different regions of the map based on the model. Would it be possible to add per-voxel coloring in solid representation at some point, similar to scolor for surface representation, to make this kind of thing possible? Cheers, Oliver.

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Exporting coarse-grained models of proteins
by Hamish Todd 06 Oct '15

06 Oct '15

Hello all, So sorry to bother you all but I've tried googling a lot of things and not found out how to create a coarse grained protein surface like this one <http://www.cgl.ucsf.edu/chimera/ImageGallery/entries/stmvrna/capsid.png>. Creating a *surface* is easy of course, but where does that nice, intuitive, bulbous STMV protein come from? And when I get it, can I export the vertex and polygon data? Hamish -- Hamish Todd 07722 400 806 Personal Website <http://www.musicofthespheresgame.com/?page_id=21>

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Saving images of all scenes in session?
by Oliver Clarke 02 Oct '15

02 Oct '15

Hi all, Apologies for yet another post and thank you for your patience! :-) Feature suggestion (or maybe this exists already?): I would like a way to iterate over all scenes in a session and save an image at each scene, with the same display settings (e.g keep background or make transparent, image format, wall-eye/cross-eye stereo, etc). This would be really very helpful when making, remaking and updating figures. Most of the time, I will have a session, say “Fig1.py”, within which I will have a bunch of scenes corresponding to each panel. It would be really advantageous to be able to take images of each scene all at once, saving each as (for example) Fig1_scene_name.jpg, Fig1_scene_name2.jpg etc. This could work in the same way as saving series of maps or models does now - just have a checkbox in the Save Image dialog for “save images for all scenes in session”, or something similar. It can take quite a while to save each image when on a slow computer, or when using graphics intensive settings such as silhouettes and shadows, so being able to save matched sets of images (e.g. low and hi-res versions, stereo versions, etc) with a couple of clicks would save a lot of time, particularly for example if you realize that the versions you saved the first time were all too low res and you want to go back and save a higher res version of every panel. I realize you guys might not have time to implement this for Chimera 1, as development of Chimera 2 is top priority, so maybe I can write a script to do this in the meantime? Is there any way to return a list of scene names using one of the built in python functions? I guess something in Animate.Scenes ought to do this, but not being much of a python programmer I can’t quite figure it out - any tips much appreciated. Cheers, Oli.

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Chimera-users October 2015