June 2025 - ChimeraX-users - RBVI Mailing Lists

Get model chain color
by Walshe, James 23 Jun '25

23 Jun '25

Hi All, Is there an easy way to get the color code for a model? Or a specific chain of that model? Let’s say I really like the default colors a model is loaded with and I want to find the exact hexa color code for each chain? Thanks! Dr James Walshe | Postdoctoral Researcher | Cramer Group Department of Molecular Biology | Max Planck Institute for Multidisciplinary Sciences | Am Fassberg 11 37077 Göttingen, Germany T: +49 551 201-2807 | E: james.walshe(a)mpinat.mpg.de | https://www.mpinat.mpg.de/cramer

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Selecting corresponding residue of different model
by Alexander Lee 22 Jun '25

22 Jun '25

Hello ChimeraX community, I have 2 pdb models of the same protein, but they don't have the same sequence numbering and length. After doing matchmaker, is there a command to select a selected residue's corresponding residue in the other model? Ex: After doing matchmaker, I selected #1/A:100 (HIS). I want a command to select #2 (HIS) in the same part of the sequence. That residue may be > 2 Angstroms from #1:100, but it's in the same position sequentially. Is there a way to do this preferably via command line? Regards, Alex

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Glasses-free Samsung Odyssey 3D Monitor support
by Michaelis, Andre Clemens 22 Jun '25

22 Jun '25

Dear ChimeraX Team, I was wondering if you had experience with the glasses-free Samsung Odyssey 3D monitor or know if ChimeraX is supporting it? Maybe you got already feedback from some users, as this seems like the perfect solution to work with! <https://www.samsung.com/us/monitors/gaming/27-inch-odyssey-3d-g90xf-4k-165h…> [samsung-logo-1-1.jpg] Odyssey G9 27" 3D 4K Gaming Monitor with Speakers<https://www.samsung.com/us/monitors/gaming/27-inch-odyssey-3d-g90xf-4k-165h…> http://samsung.com<https://www.samsung.com/us/monitors/gaming/27-inch-odyssey-3d-g90xf-4k-165h…> Thank you Best, André —————————————————— André Michaelis Max-Planck Institute of Biochemistry Dept. Proteomics and Signal Transduction Am Klopferspitz 18 D-82152 Martinsried/Munich Phone: +49 89 8578 2213 email: michaelis(a)biochem.mpg.de<mailto:michaelis@biochem.mpg.de> http://www.biochem.mpg.de/mann/<http://www.biochem.mpg.de/mann/>

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Request for Mathematical Details or Source Code for Helix Axis and Interhelical Distace/Angle Calculations in Chimera
by pupadhyay21 22 Jun '25

22 Jun '25

Respected Sir/Madam, My name is Prashant Upadhyay, and I am currently pursuing a Ph.D. in Bioinformatics and Molecular Dynamics Simulation at the Indian Institute of Technology Kanpur (IIT Kanpur), India. As part of my research, I am analyzing the structural dynamics of helical membrane proteins using molecular dynamics simulations. I have been using UCSF Chimera extensively for structural analysis. Specifically, I have been utilizing the Structure Analysis → Axes/Planes/Centroids tool to calculate the helix axes of selected helices in my protein of interest. When I select two helices, the Reply Log provides the interhelical distance and angle between the computed axes. This functionality has been incredibly useful for analyzing static structures. To extend this to a dynamic context, I am interested in applying the same axis and angle calculation to each frame of an MD trajectory. For this, I would greatly appreciate it if you could share the mathematical methodology or the relevant portion of the source code that Chimera uses to compute: 1)The helix axis from selected residues 2)The angle and the shortest distance between two helix axes My aim is to replicate this analysis programmatically over the entire simulation trajectory. Any guidance, reference, or code snippet you could provide would be immensely helpful. Thank you, Prashant Upadhyay Ph.D. Student Department of Biological Sciences and Bioengineering Indian Institute of Technology Kanpur (IIT Kanpur)

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Help with ChimeraX Boltz Structure Prediction Command for Multi-Component Systems
by Arun Gupta 20 Jun '25

20 Jun '25

Dear ChimeraX Team, I'm currently working with the Boltz structure prediction tool in ChimeraX GUI (ChimeraX 1.10 Release Candidate (15 June 2025) ) and would appreciate your guidance on the correct command syntax—particularly when specifying the single or multiple protein components via the ChimeraX GUI command line. I would like to run Boltz predictions with the following specific parameters: * nstruct: 5 (Default is 1) * recycles: 10 (Default is 3) * seed: 42 (Random numbers of seed (integer), Fixed seed value ensures reproducible results) * steering: true (enables or disables the steering potential) I tried running the following command in the command line, "boltz predict protein sequences "MKALTQRPLD... (your protein sequence)" nstruct 5 recycles 10 steering true" but it doesn't work. Could you please provide an example of the correct command format for: 1. A single molecular component (e.g., one protein sequence). 2. A multi-component system (e.g., protein + peptide or multiple protein chains). Additionally, if there are any special considerations or formatting requirements for specifying multiple sequences or components in the GUI , I’d be grateful for your advice. Thank you for your time and support. Best Regards, Arun Arun Gupta PhD, MRSC Sr. Post Doctoral Research Assistant Gillespie/McMichael Group Nuffield Dept. of Clinical Medicine, University of Oxford, Centre for Immuno-Oncology Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ Tel: + 44 (0)1865 2612913

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Determining Chirality
by steffen＠sthomas.de 20 Jun '25

20 Jun '25

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ChimeraX documentation as file download
by Michaelis, Andre Clemens 20 Jun '25

20 Jun '25

Dear ChimeraX team, Fantastic software! Since you have a great documentation and turials online, I was wondering if you could provide those also in file format (txt, pdf etc)? Would be extremely helpful for the use with chat bots! Having an assistant next to you helping you with exact commands for individual applications. Thanks a lot best André —————————————————— André Michaelis Max-Planck Institute of Biochemistry Dept. Proteomics and Signal Transduction Am Klopferspitz 18<x-apple-data-detectors://3/> D-82152 Martinsried<x-apple-data-detectors://3/>/Munich Phone: +49 89 8578 2213<tel:+49%2089%208578%202213> email: michaelis(a)biochem.mpg.de<mailto:michaelis@biochem.mpg.de> http://www.biochem.mpg.de/mann/<http://www.biochem.mpg.de/mann/>

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Structural predictions of autocatalytically cleaved proteins and visualizing a homotetramer of heterodimers
by Jernej Turnsek 19 Jun '25

19 Jun '25

Hi All, I am working on a bifunctional enzyme with these two hypothesized features: - it is first autocatalytically cleaved to form a heterodimer; - it then forms a homotetramer of heterodimers. These two events would lead to a protein assembly with 2 active sites for catalytic activity A and 1 active site for catalytic activity B. I have two questions: 1. I have modelled the initial heterodimer by "cleaving" the preprotein at the predicted autocatalytic cleavage site and feeding the resulting two aa sequences to the AlphaFold Server. Is there a better way to predict heterodimerization of such proteins using AlphaFold? 2. Is there a way to tetramerize the resulting AlphaFold heterodimer from 1. in ChimeraX? Thank you and best wishes, Jernej -- Jernej Turnšek, PhD (hear my name <https://www.name-coach.com/1b5bbbb9-5b8c-46bc-8678-a30c25e11bc3>) Postdoctoral Scientist Department of Plant and Microbial Biology University of California, Berkeley Personal Website <https://plantandmicrobiology.berkeley.edu/users/jernej-turnsek>

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query 2fo-fc map
by mariela Urrutia 19 Jun '25

19 Jun '25

HelloCould you tell me how can I see the 2fo-fc map in a particular residue?Thanks you in advance.Mariela

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Method of calculation of SASA
by komatireddy.nikhita＠gmail.com 18 Jun '25

18 Jun '25

Dear Sir/Madam, I am Nikhita, an undergraduate student working on a research project and I am considering to use ChimeraX to calculate solvent accessibility surface area (SASA) for some residues of a protein. However, since I would like to calculate relative solvent accessibility surface area manually, I am using the reference maximum SASA values from Tien et. al. (2013) which mentions that using softwares that calculate SASA using the Lee & Richards method are preferable. As such, I would like to ask if ChimeraX uses the Lee & Richards method to calculate SASA as I could not find much about this on the ChimeraX website. Thank you! Warm regards, Nikhita

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