- ChimeraX-users - RBVI Mailing Lists

Tunnel visualisation
by Kelly May Frain 20 Apr '23

20 Apr '23

Hello, I am using ChimeraX to visualise a tunnel found in my membrane protein using caver. I can put together the protein pdb and tunnel pdb perfectly. However, crucial to the figure is how the tunnel has a different radius throughout. In PyMol I can see this, but when I set the tunnel to sphere in chimeraX, it’s continuously the same diameter. I can change the colouring to b-factor and here it acknowledges the atom b factor range of 0.8 - 4-8 but I want to visualise the differences. Please can someone help me with a command? BW, Kelly

3 4

Hopefully simple plugin development question
by BARRY E DEZONIA 19 Apr '23

19 Apr '23

Hello, I am looking at writing a plugin for chimerax that takes a pdb and runs some python code that will calc some stuff hand stuff to other programs. I know how to do this. What I want to know is how to find the current model's name / associated pdb filename from my plugin. Imagine my plugin really is just a "Run" button that looks up the current model, generates the associated pdb filename, and passes that name to my python script. Can someone tell me how in a chimerax plugin I can make the call that will give me the pdb filename I want? I've read much of the developer docs and could not find what I was looking for.

4 6

Unable to select individual glycans in ChimeraX
by Coillie, Julie van 19 Apr '23

19 Apr '23

Dear ChimeraX, Is there any way to select one individual glycan on a crystal structure? The crystal structures I'm working with have multiple domains, each with glycans. I want to annotate the glycan per domain (every domain & glycan in a specific color). However, I can't edit individual glycan structures. The glycans are grouped under Non-standard residues, e.g. MAN, NAG, ... However, when selecting e.g. MAN, all the MAN structures light up, which are found on all 3 domains. An alternative would be using the sequence and annotating each individual sugar by using "select". However, these Non-standard residues are not in the sequence (they are when uploading this in Pymol), so I don't know a position to select them on. Is there a way to find the "sequence" for non-standard residues or any other way to annotate an individual glycan. Thank you in advance, Julie Van Coillie ________________________________ Disclaimer: http://www.sanquin.nl/e-maildisclaimer ________________________________

2 2

Command use
by Wojciech Witek 19 Apr '23

19 Apr '23

Dear ChimeraX Team, I am trying to change this mesh properites because it covers the ligand too much (attachment). I wanted to make the lines thinner or transparent or divided in different ways. I could not find anything in the GUI so I searched for commands but apparently I use them wrong. Could you please guide me on how to use commands, let's say like this one : surfaceSmoothing true | false? If I type "true", I see an error in the log file. Where can I find what arguments should be use with a specific function?I had the same struggle with depth cueing, ribbon style edition and many other functions. ChimeraX is a great software but using GUI is so much easier to get familiar with, learn and utilize changes, comparing to command line. See attached file containing ligand, mesh and a log full of errors from pasted commands. Please, keep it confident because it is unpublished yet. Regards, Wojciech Witek -- Logo *Wojciech Witek* *| PhD Student Department of Structural Biology of Eukaryotes* Institute of Bioorganic Chemistry, Polish Academy of Sciences Noskowskiego 12/14 | 61-704, Poznań *email:*wwitek@ibch.poznan.pl *tel.:*61 852 85 03 *int.:*1347 **** ** facebook <https://www.facebook.com/ICHBPAN> twitter <https://twitter.com/ICHBPAN> instagram <instagram.com/ichbpan> WWW <https://portal.ichb.pl/>

2 1

deleting alternate locations
by Elaine Meng 18 Apr '23

18 Apr '23

> On Apr 18, 2023, at 3:07 AM, Yu GUO 郭宇 <guoyu60(a)westlake.edu.cn> wrote: > > Dear, > > I am using Chimera/ChimeraX. I have 2 questions: > > I cannot open ChimeraX (win10 version) recently. Is there any problem in the server? > > I have a PDB file with two structural populations. In Chimera, how to delete the part with fewer population (say 40%)? I rememer it can be realized in the command line, but I forgot. > > Best wishes > Dear Sir, In the future, please use the following addresses (CC'd here) for general questions about the programs: chimerax-users(a)cgl.ucsf.edu for ChimeraX questions chimera-users(a)cgl.ucsf.edu for Chimera questions (where you sent this question is for commercial licensing questions -- thanks) (1) after you download the program, it does not depend on our servers to start. The issue is something with your own setup. The most likely problem is that you need to update your graphics driver but we would need more information from you to say anything else. (2) if you mean atomic occupancy, - in Chimera you can use Dock Prep (menu: Tools... Structure Editing... Dock Prep) and turn on the option "If alternate locations, keep only highest occupancy". You can turn off all the other options if you want. <https://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/dockprep/dockpre…> - in ChimeraX, it is not currently in the Dock Prep GUI, but you can use the "altlocs clean" command which would delete all the altlocs that are not currently used. By default, the highest-occupancy ones are the ones that are used, so this would delete the lower-occupancy ones (e.g. your 40%). You can change which altlocs are used with "altlocs change" and show a list of them with "altlocs list" <https://rbvi.ucsf.edu/chimerax/docs/user/commands/altlocs.html#clean> If you need a PDB file then you can save PDB in a separate step, e.g. using File menu or a command. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

1 0

Permission denied to "Spin Movie"
by Pam Cook 17 Apr '23

17 Apr '23

Hi, I just installed ChimeraX on macOS Catalina 10.15.7. During installation, it asked me to allow access to desktop files and I said NO. But now, when I try to create a SpinMovie file, I get the message: Permission denied reading directory "/Users/pam/Desktop" while trying to determine next unused file name movie#.mp4. I guess I should have said YES to the question above. How can I fix this? Thanks, Pam

2 1

Question about using ChimeraX
by 韩磊 17 Apr '23

17 Apr '23

Dear Sir， I hope this mail finds you well. I am a professional researcher from Tianjin Medical University, China. I have encountered some difficulties in learning to use ChimeraX software. First, I would like to know if the software can be used to construct a graph of the process of channeling proteins from closed to open state (e.g., Appendix ). Second, we can currently only download and import a model of the closed state of a protein into the software, but it does not reflect its conformational changes, so I would like to know which option within the software can change the conformation of the protein. Sincerely yours, Lei Han, Ph.D. Tianjin Neurological Institute, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin 300052, China

2 1

Could you please inform the best advice to solve a structure via colabfold when GPU is an issue? I tried some routes already.
by Josh Gutierrez 14 Apr '23

14 Apr '23

Hello, I recently submitted a job through ChimeriaX and used the "prediction" task for it to be solved via Alphafold2-- the sequence is about 1300 amino acids in length. However, the protein could not be solved by alphafold2 and the colabfold reports the GPU consumption is too high for the structure to be solved. To resolve the problem, I tried breaking the sequence into two to solve this expected bimodal protein individually (into two separate structural parts) and even in combination purchased "compute units" for more memory and storage to do this, but the structure can't be solved without high predicted error. Please let me know what you think may resolve this issue. Currently, I am working with an external professor who may be able to connect me with a collaborator on this issue at UCSF if there is a cluster or core we can use to expedite the process to solve this structure I am addressing. Please let me know your thoughts at your earliest convenience. Please also let me know if you need any more information! Many thanks, Josh Gutierrez

3 4

Measure inertia and measure center on aligned density maps and models
by Kevin Felt 13 Apr '23

13 Apr '23

Dear developers, I am trying to compare the center of mass of multiple cryo-EM maps and models. The receptor is the same in all cases, just the ligand bound in the binding pocket varies. I want to show a directionality to how the ligands are binding in the pocket between the structures, so I have aligned the maps and models together and am attempting to run "measure center" and "measure inertia" to initiate this comparison. However, when I run these commands, the output markers and ellipsoids are not positioned in an aligned fashion as their parent objects, but rather in there initial positions before alignment, which is not useful for comparisons of the subtle movements between structures. Additionally, if I could get the measurements to work on the aligned structures, is there a tool in ChimeraX that would allow me to draw vectors from a reference point to the center of masses? Furthermore, is center of mass the correct parameter for comparison of densities that are variable in shape? (e.g. comparing the relative position of a long and flat density to a short a globular density?) Thank you! Sincerely, -- Kevin C. Felt PhD Candidate - Chakrapani Lab Department of Physiology and Biophysics School of Medicine Case Western Reserve University

3 2

Modeling post-translational modifications
by Guillaume Gaullier 13 Apr '23

13 Apr '23

Hello chimerax-users, I am trying to model a PTM, and the most sensible way to me seems to use the swapaa command and specify the sensible monomer from the PDB Chemical Component Dictionary as the target residue. Here is what I tried (residue #1/a:9 is a Lys): open 1kx5 swapaa #1/a:9 KCX And the error I got: Dynameomics rotamer library does not support KCX I tried all the rotamer libraries listed in the swapaa help page ( https://www.cgl.ucsf.edu/chimerax/docs/user/commands/swapaa.html#rotLib ), but none of them can provide stereochemical info for KCX. I can open the monomer I want (carbamylated Lys) with: open ccd:KCX But of course in this case it’s floating by itself as a new model, not incorporated in the protein sequence and structure I am interested in. Is this the correct way to model a PTM? If it is, where can I find a rotamer library that will contain the stereochemical info for KCX, and how do I tell ChimeraX to use it? If it is not how modelling a PTM is done, then how else should I do this? Thank you in advance, Guillaume När du har kontakt med oss på Uppsala universitet med e-post så innebär det att vi behandlar dina personuppgifter. För att läsa mer om hur vi gör det kan du läsa här: http://www.uu.se/om-uu/dataskydd-personuppgifter/ E-mailing Uppsala University means that we will process your personal data. For more information on how this is performed, please read here: http://www.uu.se/en/about-uu/data-protection-policy

3 5