March 2024 - ChimeraX-users - RBVI Mailing Lists

Enclose volume within radius?
by Oliver Clarke 10 Mar '24

10 Mar '24

Hi ChimeraX-ers, Finding an equivalent contour level for 3D classes in cryoEM can be challenging, particularly if the density histograms are sufficiently different that setting a single level does not suffice (and particularly when comparing many classes from a large classification). The options "enclosevolume" and "fastenclosevolume" for the "volume" command are very useful for this (e.g. "volume #* fastenclosevolume 200000"), but fail in the presence of compositional heterogeneity (if there is more ordered stuff in one class and the volume is fixed, the contours will no longer be equivalent). To address this, would it be possible to add a "within_radius" modifier for the "volume fastenclosevolume" command? This would mean one could then set a fixed volume to be enclosed by the contour within a set radius of either the center of rotation, or of an atom selection, making the contour levels at least locally equivalent (which is often what one wants for the purposes of comparison). Cheers Oli

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Notepad or info dialog in ChimeraX?
by Oliver Clarke 08 Mar '24

08 Mar '24

Hi, Is there a command in ChimeraX to launch a notepad? Or to display some text? I would like to make a button that will launch a little window with some info about shortcuts and the like. In Chimera, there was a notepad (the contents of which could be saved with a session) - does something similar, or some kind of custom info dialog, exist in ChimeraX? Cheers Oli

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Question about accreditation
by Enrico Martinez 08 Mar '24

08 Mar '24

Dear ChimeraX users ! I am wondering if I am obligated to mention the name of the ChimeraX software if I use it to creat a cool image and post it to any social media like Facebook or Instagram ?? Or alternatively on the personal web page ? Obviously it could be obligatory for a scientific publication but what s about usage in fully artistic context ?? Many thanks in advance ! Yours sincerely Enrico

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Loading multi-frame pdb using open command
by Enrico Martinez 08 Mar '24

08 Mar '24

Dear Chimera-X users! I have a question regarding the handling of a trajectory saved in multiple-pdb format. Loading such ensemble using dedicated open command typically load all frames at once: open ./my_trajectory.pdb coordset true Would it be possible to specify the range of the loaded frames to reduce the time for data loading e.g. i) to load first 3000 frames or ii) to load from 50 to 5000 frames? Many thanks in advance ! Best wishes, Enrico

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Trying to join two structures unsuccessfully
by Maja Divjak 07 Mar '24

07 Mar '24

Hi there, Hope you're well. I am trying to join the two structures as shown in the image attached. I would like to join the disordered chain shown in green to the purple chain and the residues I would like to join are highlighted. I would like the green disordered chain to be dragged over to join the purple structure without moving any of the ordered domains that are linked to it (orange). I have tried selecting individual atoms ie N and C atoms from these residues (as shown) and using the command tools > structure editing > build structure > join models from the drop down menu. I adjusted C-N length to 1.6 and set to 'move atoms in larger model', thinking this would move the green chain. Hitting apply gives me the error dialogue 'No atoms selected'. I also tried Adjust Bonds > with options for Delete selected bonds > and add reasonable. There are no error messages, but the log says that no bonds were created. Not sure what I'm doing wrong or what the correct process is for joining models in this way please? Is this even possible? Clearly I'm not selecting the atoms appropriately. I am using Chimera X version 1.6.1 Thanks so much and best wishes, Maja Dr Maja Divjak BAppSc(Hons), PhD, Grad Cert 3D Animation (AFTRS) Biomedical Animator Office of Cancer Research [Description: cid:image001.jpg@01D35ECE.31407C60]

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ISOLDE: unable to work with map after selecting another model
by Alexis Rohou 06 Mar '24

06 Mar '24

Hi Tristan, ISOLDE users, Sometimes it's useful to create a new model (e.g. by merging the model of the protein you've been working on with an initial model of the ligand) and then continue working with this new model in ISOLDE. For me, this leads to trouble. Specifically, here's what I do: - start ChimeraX - open a PDB and a map - start ISOLDE - select the PDB model in the "Working on" dropdown - select the map in the "From loaded volume" dropdown - do some simulations until I'm happy with the protein - open a PDB of the ligand - combine the ligand model with the protein model - select the combination model in the "Working on" dropdown - press "start simulation"... get warning "about to start simulation with no map" - press Cancel - check the "From loaded volume" dropdown - it's not possible to select the already-loaded map, which is in the initial "Data manager" Is this intended behavior? I was hoping to be able to continue working against the same map. Cheers, Alexis

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Silhouettes only on selected models
by Pedro Bule 06 Mar '24

06 Mar '24

Hi, I'm writing to know if there is a way to turn on the silhouette graphical option only on selected models in ChimeraX, or is it just a global option? I have a model of an enzyme with its ligand and another model with the electron density loaded from a .map file. I want to display the electron density around the ligand as a slightly transparent mesh without silhouettes (see below) while still having silhouettes on the enzyme and ligand. Is there a way to do this? The silhouettes on the mesh make it too dark and dense (see image 2). Thank you very much Pedro Bule [image: image.png] [image: image.png] -- *Pedro Bule* *Assistant Professor* GLYCOBIOLOGY AND STRUCTURAL ENZYMOLOGY LAB *P:* (+351) 21 365 28 84 // 431379 | pedrobule(a)fmv.ulisboa.pt <email(a)fmv.ulisboa.pt> *Centro de Investigação Interdisciplinar em Sanidade Animal* Faculdade de Medicina Veterinária Av. Universidade Técnica | 1300-477 Lisboa | PORTUGAL

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Connection to GPU
by Minu Chaudhuri 06 Mar '24

06 Mar '24

Hello, I am trying to build a multimeric structure using AlphaFold collab, but it is not connecting to the GPU. How can I get a connection? Is there a fee for this? How to pay for this? Thanks for your help. Minu Chaudhuri, Ph.D. Meharry Medical College Nashville TN 37208 USA

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need Section 508 compliance statement
by Weiss, Carol 06 Mar '24

06 Mar '24

Hello, I would like to use ChimeraX, but the FDA IT administrators will not download the Chimera X software without a statement about its Section 508 compliance for users. Would you please send me available Section 508 compliance information for this software? Thank you, Carol Weiss

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Improvement suggestion: single letter code for swap
by Vorländer,Matthias Kopano 06 Mar '24

06 Mar '24

Dear ChimeraX team, A small feature request: It would be helpful if the swapaa command could accept the single letter code for amino acids as well as the three letter code. This makes it easy to quickly fix a sequence, i.e based on a sequence that is open in the sequence viewer. Many thanks, Matthias

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