June 2025 - ChimeraX-users - RBVI Mailing Lists

Structural predictions of autocatalytically cleaved proteins and visualizing a homotetramer of heterodimers
by Jernej Turnsek 20 Jun '25

20 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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Re: [Chimera-users] query
by Eric Pettersen 18 Jun '25

18 Jun '25

Hi Mariela, I don’t really know what a “superior menu” is. Maybe you could clarify? If you mean a popup menu, you get that by clicking the right button on your mouse (or the equivalent on a trackpad). Since this is a ChimeraX question, I have cc’ed the chimerax-users list and directed replies there. Chimera and ChimeraX are separate programs and have separate mailing lists. --Eric Eric Pettersen UCSF Computer Graphics Lab > On Jun 12, 2025, at 9:23 AM, Mariela Urrutia via Chimera-users <chimera-users(a)cgl.ucsf.edu> wrote: > > Hello, > Could you give me direction to add the superior menu in ChimeraX 1.9 (2025-3-6)? > Thanks you in advance! > Mariela > > Dra. Mariela Urrutia > Investigadora > Centro de Investigaciones Endocrinológicas “Dr. César Bergadá” (CEDIE) > CONICET – FEI – División de Endocrinología, Hospital de Niños Ricardo Gutiérrez > > Gallo 1330 – C1425EFD Buenos Aires – Argentina > Tel. (+54-11) 4963-5931 int 290 > murrutia(a)cedie.org.ar <mailto:murrutia@cedie.org.ar> 🌎 www.cedie.org.ar <https://cedie.conicet.gov.ar/> 👥 Facebook <https://www.facebook.com/CEDIE-Centro-de-Investigaciones-Endocrinol%C3%B3gi…> Instagram <https://www.instagram.com/cedie.conicet/> > > > _______________________________________________ > Chimera-users mailing list -- chimera-users(a)cgl.ucsf.edu <mailto:chimera-users@cgl.ucsf.edu> > To unsubscribe send an email to chimera-users-leave(a)cgl.ucsf.edu <mailto:chimera-users-leave@cgl.ucsf.edu> > Archives: https://mail.cgl.ucsf.edu/mailman/archives/list/chimera-users@cgl.ucsf.edu/

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Cross section visual of map model fit
by Das, Abhinaba 18 Jun '25

18 Jun '25

Dear community, How do we go about creating an image like this where the density around the model is quite sharp, that is, there is almost no interference from the top or the bottom density? Tried clipping volume and volume zone; both didn’t seem to give quite the same effect. Thanks, Abhi [cid:image001.png@01DBDFC6.1AD09EC0]

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cartoon selection by color
by Михаил Егорочкин 18 Jun '25

18 Jun '25

Hi, my name is Mike and I placed some atomic (cif) models in my chimera session. Also I performed manual coloring of some protein domains (watch the picture). Now I have realized that I want to change uncolored parts (#d2b48c). So manually it will take a lot of time (i have a lot of these models), is there any way to select by cartoon color. I imagine this as some command or script like: "sel by color #d2b48c" and after that i go action color and choose my desired color. Please help me.

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Model loops with MODELER in ChimeraX
by Alexandra Zahradnikova 17 Jun '25

17 Jun '25

Hello, I have recently watched a Youtube video (https://www.youtube.com/watch?v=GV6jHhxR5T4) about completing loops with Modeller in ChimeraX. However, the structure I want to model is only a part of the actual molecule, and I want to replace one unresolved segment (300 residues long) with 11 glycines. When I upload both, the FASTA file with the sequence as it should look after completion of the loops, and the PDB file of the incomplete structure, I am not able to align them together in order to perform the modelling. - If I use the original PDB file containing the SEQRES part, the association is performed but produces mismatches after the start of the unresolved sequence. - If I use the PDB file without the SEQRES part, I am not able to perform the association. Can anybody help me? Thanks in advance Sasha ________________________________________________________________________ Alexandra Zahradníková, PhD Department of Cell Cardiology Institute of Experimental Endocrinology Biomedical Research Centre SAS Dúbravská cesta 9 845 05 Bratislava Slovakia Mobile: +421 908 069 796

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cysteine palmitoylation with ISOLDE?
by Alexis Rohou 16 Jun '25

16 Jun '25

Hi ISOLDE users & Tristan, Has anyone got experience building a palmitoylated cysteine residue? I'd appreciate any pointers you may have. Based on how glycosylations can be built (see thread <https://mail.cgl.ucsf.edu/mailman/archives/list/chimerax-users@cgl.ucsf.edu…>) I was thinking to start with isolde add ligand PLM but that fails with "ValueError: No template for residue type PLM" Are we in covalent ligand (unsupported) territory here? Cheers, Alexis

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Parallel capabilities of ChimeraX
by Alexandra Zahradnikova 16 Jun '25

16 Jun '25

Dear All, In the ChimeraX article (doi: 10.1002/pro.3235) it is written: "ChimeraX is built using standard software toolkits that utilize advanced Graphics Processing Unit (GPU) capabilities and the parallel computing capabilities of modern hardware. " However, when I run ChimeraX on Windows10, Windows11, or Linux, it only grabs one thread and does not use the GPU at all (neither the built-in one not the NVIDIA one). Am I doing something wrong? Best regards Sasha

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Method of calculation of SASA
by komatireddy.nikhita＠gmail.com 16 Jun '25

16 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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