- Chimera-users - RBVI Mailing Lists

Hide side chain
by Zhu, Xiaoyan 12 Dec '16

12 Dec '16

Hello, I am using UCSF Chimera to generate figures of protein crystal structures. Some crystals, if open in Chimera, automatically show the side chains of some amino acids. I want to hide those side chains in my figures. I wonder if there's an easy way to do it. Thank you! Have a good one, Xiaoyan Zhu Ph.D. Candidate Department of Biological Sciences, Marquette University

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Multiple transparent objects
by Daniel Asarnow 12 Dec '16

12 Dec '16

Hi, I'm having some trouble with a movie of a morph between structures of the same protein bound to two different ligands. The basic idea is a closeup of the binding pocket, and as the morph progresses the initial ligand becomes transparent while the second one becomes opaque. The result is a similar effect to crossfade, only the morph animation is playing simultaneously. I've tried both the screen capture and ray tracing methods, with the following results: Screen capture - When a ligand is almost entirely transparent, a white silhouette is shown at the highest z-order, blocking what's behind. - There is a "pop up" effect when the ligands suddenly switch z-order at the beginning and end of my animation. - Single-layer and flat transparency options don't help. Ray tracing - Multiple transparency is fine. - Reflections and shadows are not made transparent. - E.g. when one ligand is 100% transparent, the reflections and shadows are still visible as white lines and dark spots. Maybe someone here has some insights on my transparency problems? A way to use crossfade instead would be even better. I can record movies with the two ligands separately and then crossfade them manually with ffmpeg. However, it would be nice to have this working entirely in chimera, especially for some more complicated animations I have in the works. Best, -da

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.pyc session file
by Luca Pellegrini 12 Dec '16

12 Dec '16

Hi, How can I open in Chimera a saved .pyc session file? When I try, Chimera reports the following error message: Error while processing /Users/lp212/Dropbox/<filename.pyc>: .pyc files are not portable; please use .py file instead Unfortunately I don’t have the .py file, Chimera doesn’t seem to have saved it (not sure why). Thanks, Luca Luca Pellegrini, PhD Department of Biochemistry University of Cambridge 80 Tennis Court Road Cambridge CB2 1GA UK Email: lp212(a)cam.ac.uk Phone: 0044-1223-760469

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Selective lighting
by Oliver Grant 12 Dec '16

12 Dec '16

Hi all, Is it possible to use the lighting command and have it apply only to particular models? I'd like my ligand to "pop" out by having a light that only shines on it, and not the protein. Oliver

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Fit-to-window for procedurally generated images
by Mike Sivley 09 Dec '16

09 Dec '16

I am procedurally generating images of protein structures using a Chimera python script. I can center the protein structure within the viewing window, align the protein to emphasize certain elements, set the output size of the final image, and manually apply a scale factor to the view, but I have not found a way to ensure that the protein structure is maximized (but fully contained) within the final image. Is there a "fit-to-window" command that will automatically scale the view in this way? Thanks! Mike Sivley

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How to find symmetry parameters for icosahedral molecule
by Haselbach, David 08 Dec '16

08 Dec '16

Hi everyone, sorry to ask such a basic question. I have a cryo EM density map 3.2 A of a icosahedral molecule and I already build the model of the monomer. I would like to place the remaining 59 copies and calculate the BioMT matrix for it. I started playing around with the sym command, but I couldn't get it working nicely. It's probably a problem of the coordinate system, but I couldn't figure it out. Than I thought there must be an automatic way and I tried Multifit but also this failed me miserably as the runs fail continuously with "stderr". So I was wondering is there a protocol to do this? Already thank you for any suggestions, David Dr. David Haselbach Max-Planck-Institute for biophysical Chemistry Department for structural Dynamics Am Fassberg 11 37077 Germany Tel. +495512011302

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symmetry axis
by chemocev marker 08 Dec '16

08 Dec '16

Hi All I am interested to measure the symmetry axis of individual sub-unit (chain A & chain B) along with the symmetry axis of the heterodimer (AB). Each chain has 2 domains and 2 fold rotations axis, and I can measure by removing 1 chain and measure for the other. Is there way to measure the inter-domain symmetry axis of the heterodimer molecule. best Jiri

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Fwd: chimera minimize option
by Jacqueline Vitali 07 Dec '16

07 Dec '16

It puckers ASN and ASP (and probably other amino acids). (I run it to relieve steric conflicts only) How do you fix this? And can you run it with the whole protein selected?

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question
by A G Szabo 06 Dec '16

06 Dec '16

You have been very helpful in explaining different items that use the command line. I have a PDB file that was determined by NMR. Thus there are a large number of chains number as pdb (#0.1) Chain A etc. So I know that I can select a single chain, and build up an image with Chains A, B, etc using the #0.1 chain number. I want to visualize three Gly residues in one chain. So I learned that I can use the command ribbackbone to visualize the backbone atoms of the amino acids that I want to show. So when I use that command all the backbone atoms of the residues selected are visualized including the side chains. I also know that if I use the command ~ribbackbone all the backbone atoms are suppressed leaving only the atoms of the side chains. I know that without any residues or atoms specified the command applies to the whole model. Now as I said that I want to visualize three Gly residues in one of the chains. The Gly residue numbers are 33, 37, 38. They are on Chain #0.1 K. The information on the ribbackbone in the Chimera users guide, indicates that I should be able to do this by using parameters termed atom-spec. i.e. ribbackbone atom-spec <frameatom_spec.html> I looked elsewhere for how to designate the parameters for atom-spec and tried a few things, but I was not able to achieve the specificity of showing the backbone atoms of only the Gly residues. I don't think that I have to indicate that I want only the Gly residues in Chain K #0.1 because I can select the Gly residues from the sequence of Chain K #0.1. So after this long description of what I want to do, would you kindly inform me of how I can visualize the backbone atoms of only Gly. Thank you Arthur G. Szabo

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Re: [Chimera-users] Chimera -> Povray
by Elaine Meng 05 Dec '16

05 Dec '16

Hi Lothar, If you use "File… Export Scene” (instead of Save Image) or the “export” command, there is an option to save a file for POV-Ray without rendering: <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/export.html> 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 > On Dec 5, 2016, at 3:07 PM, esserlo(a)helix.nih.gov wrote: > > Hi, > currently, I am using chimera to make a figure for publication and render > the result in povray. However the figure is a bit complex - with a gradient > background just to mention one thing- so that I have to edit the .pov file. > Is there a way to ask chimera to output the .pov file but not render it in > povray right away (that would save time as I need to edit it first!). > > Unfortunately in the "save image" menu, using povray, I did not find a > checkbox that would enable chimera to write out .pov only. > Thanks for any advice. > Lothar >

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