- ChimeraX-users - RBVI Mailing Lists

Dividing a huge model (& map) into smaller chunks
by Alejandro Buschiazzo 12 Mar '25

12 Mar '25

Dear chimeraX developers/users Using version 1.9, I am trying to divide a very big mmcif model (230K + nonH atoms; >130 chains) and corresponding mrc map, into a number of smaller mmcif files (and corresponding cropped maps, covering just those parts). What I’ve tried so far unsuccessfully: I can create dummy atoms with build start atom, at desired x,y,z points, so that I can then use select zone to select a radius and keep parts near each dummy atom. Yet, that is suboptimal: I would largely prefer to keep (build) boxes, and not spheres, ensuring complete recovery and no blind spots. So that each box slightly overlaps with the neighboring one, and systematically covers the whole original map volume. 1. How can I generate a script that will do this "systematic windowing” screening, making boxes of a defined side-length at each step, and keeping the model within? 2. How should I then crop the original map, so that it covers each box (with a small padding on the borders)? 3. How should I stitch back the models, so that I don’t loose any atomic coordinates information? (of course that stitching will be done after I do some refinement work on each boxed model vs map) So sorry for the many questions! I’ve been trying hard to find this kind of strategy, and just can’t seem to succeed…. Thank you very much in advance Alejandro -- Alejandro Buschiazzo, PhD Associate Professor Laboratory of Molecular & Structural Microbiology Institut Pasteur de Montevideo Mataojo 2020 Montevideo 11400 URUGUAY Phone: +598 25220910 ext. 120 Fax: +598 25224185 https://pasteur.uy/en/laboratories/molecular-and-structural-microbiology/

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General ?s - Foldseek (Sequence Plot) and Similar Structures Table
by Emir MALOVIC 11 Mar '25

11 Mar '25

Hello, Quick question: When I load the sequence plot, I receive 2 sequence images separated by a very large black space. When I save the image as a PNG, the black space between the sequence images is retained. Basically, the image is mostly black space. Is there a way to change that or is this a bug? Am I able to somehow copy the Similar Structures table or export it into Excel? A copy/paste function would be ideal and quick. I am using the Chimera 1.10 dev. Please let me know at your earliest convenience! Thank you, Emir

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Suggestion for improvement
by James Raymond 11 Mar '25

11 Mar '25

I love ChimeraX and use it often for my work, e.g. this one <https://www.pnas.org/doi/10.1073/pnas.2421910122>. When using AlphaFold to predict protein structure, the sequence is pasted into the sequence box. It does not allow entering the fasta name ">name" before the sequence.. Allowing a name to be included can avoid much confusion. Presently, the screen shows the output as "best_model" which becomes very confusing when several best models are shown on the screen. James Raymond Univ. Nevada Las Vegas

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What is the .exe file for ChimeraX Toolbox?
by m.i.bashir＠bham.ac.uk 11 Mar '25

11 Mar '25

Hi all, First time posting here. I'm looking to find the name and location of the file/folder that manages the ChimeraX in-app browser. The way I launch the browser is to go to 'tools' in the top bar, then press 'more tools', and then it brings up the ChimeraX Toolshed Where is the .exe file that controls this in app browser? I am attempting to find the .exe file and black list it, so we can use ChimeraX for an exam Thanks,

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SASA in MDS
by Gabriel López Velázquez 10 Mar '25

10 Mar '25

Dear Elaine, I am sorry; I did not state the subject of my previous email. I would ask for help. How can I calculate SASA as a function of time from the MD simulations in Chimerax? What archives need to perform it? Thanks in advance! Gabriel.

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(no subject)
by Gabriel López Velázquez 10 Mar '25

10 Mar '25

Dear Elaine, I would ask for help. How can I calculate SASA as a function of time from the MD simulations in Chimerax? What archives need to perform it? Thanks in advance! Gabriel.

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Inquiry About Favorable Contacts and Display Methods in ChimeraX
by 田畑　健士郎 07 Mar '25

07 Mar '25

Subject: Inquiry About Favorable Contacts and Display Methods in ChimeraX Dear ChimeraX Developers, My name is Kenshiro Tabata. I hope this email finds you well. I am currently using ChimeraX to analyze the effects of point mutations on protein structure, particularly in cases where a larger side chain (e.g., methionine) is replaced by a smaller one (e.g., valine). In such cases, I expect that interactions with the opposing amino acids may be reduced due to the decreased side-chain volume. To investigate this, I would like to ask for your guidance regarding the interpretation and visualization of favorable contacts. ________________________________ 1) Understanding Favorable Contacts I understand that the contacts command identifies all types of interactions, whereas the clashes command detects only unfavorable interactions. Based on this, I interpreted the positive VDW overlap as indicating unfavorable (repulsive) interactions, while an overlap between 0 and -0.4 represents favorable (attractive) interactions. Could you confirm if this understanding is correct? ________________________________ 2) Best Approach for Displaying Only Favorable Contacts To analyze how the mutation affects interactions, I would like to display only favorable contacts. Below is the approach I have considered: Proposed Approach 1. Retrieve all interactions (favorable, neutral, and unfavorable) using the contacts command contacts overlapCutoff -0.4 saveFile all_contacts.txt 2. Retrieve only neutral and unfavorable interactions contacts overlapCutoff 0 saveFile non_favorable_contacts.txt 3. Compute the difference between these two sets using Python, extract only favorable contacts, and format them into a ChimeraX pseudobond file # File paths all_contacts_path = "all_contacts.txt" non_favorable_contacts_path = "non_favorable_contacts.txt" favorable_contacts_path = "favorable_contacts.pb" # Read files with open(all_contacts_path, "r") as f: all_contacts = set(f.readlines()) with open(non_favorable_contacts_path, "r") as f: non_favorable_contacts = set(f.readlines()) # Extract favorable contacts favorable_contacts = all_contacts - non_favorable_contacts # Convert to ChimeraX pseudobond file format with open(favorable_contacts_path, "w") as f: f.write("; Pseudobond file for favorable contacts\n") f.write("; radius = 0.1\n; color = green\n; dashes = 6\n") for line in favorable_contacts: parts = line.strip().split() if len(parts) >= 4: atom1 = f"/{parts[0]}:{parts[1]}@{parts[2]}" atom2 = f"/{parts[3]}:{parts[4]}@{parts[5]}" f.write(f"{atom1} {atom2}\n") 4. Load the extracted favorable contacts into ChimeraX for visualization open favorable_contacts.pb Would this be an appropriate approach? Alternatively, is there a simpler or more precise way to achieve this in ChimeraX? I appreciate your time and assistance, and I look forward to your advice. Best regards, Kenshiro Tabata

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AI in ChimeraX
by Elaine Meng 07 Mar '25

07 Mar '25

On Mar 7, 2025, at 6:01 AM, Veach, Kevin G. <kevin.veach(a)uky.edu> wrote: > > Hi Elaine: > Does Chimera-X use Artificial Intelligence or Large Language Learning Models? > Thank you, > > Kevin > Kevin Veach, Computer Support Specialist II > University of Kentucky, Animal & Food Sciences Dept. Hi Kevin, Please use the chimerax-users(a)cgl.ucsf.edu <mailto:chimerax-users@cgl.ucsf.edu> address CC'd here for general questions about ChimeraX -- I'm not the top expert on all parts of ChimeraX, so you may get better answers from other developers or our user community. Regarding your question, my understanding is that ChimeraX itself does not use these kinds of calculations, but it has tools that interface to web services or other calculations (run outside of ChimeraX) that do use them. The ones that I can think of are AlphaFold/ColabFold and ESMFold: <https://rbvi.ucsf.edu/chimerax/docs/user/tools/alphafold.html> <https://rbvi.ucsf.edu/chimerax/docs/user/tools/alphafold.html#predict> <https://rbvi.ucsf.edu/chimerax/docs/user/tools/esmfold.html> <https://rbvi.ucsf.edu/chimerax/docs/user/tools/esmfold.html#predict> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Resource for Biocomputing, Visualization, and Informatics Department of Pharmaceutical Chemistry University of California, San Francisco

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Creating movie in ChimeraX from YASARA simulation
by ibogdanov 07 Mar '25

07 Mar '25

Hi ! I have the following question - How can I create a movie, when I cannot use the YASARA.sce file from which I converted/extracted xtc.file(the trajectories) when I have all the snapshots(pdb and sim.files) created as separate files during the performed simulation in YASARA...I've uploaded for example the first pdb file of the series and the xtc.file but isn't the saved xtc.file(trajectories) of the whole simulation(for all the structures)? How would you suggest me to solve this problem, if ChimeraX doesn't support sce.files ? Thank you in advance! Kind Regards, Ivan Bogdanov

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Problem installing on OSX
by Thom Hughes 06 Mar '25

06 Mar '25

I apologize for the dumb question, but here it is. I want to install the isolde extension. When I go to more tools, isolde, and click the install button a .whl file downloads correctly. But then nothing happens. I’m running OSX 15.3.1. thanks in advance for any pointers!

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