March 2024 - ChimeraX-users - RBVI Mailing Lists

pTM and ipTM Score Access
by Haley V Goodwin 27 Mar '24

27 Mar '24

Hello! I am using ChimeraX to use AlphaFold Multimer. I have read from a couple of places that AF provides pTM and ipTM scores to evaluate the quality of the models. I was wondering how I access these values from ChimeraX. I have looked through the results zip file, but can’t seem to find where these values may be stored. Thank you so much for your help! Best, Haley Goodwin

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Re: isolde write phenixRsrInput (how to restrain ions?)
by Shahid, Taha (Dr.) 27 Mar '24

27 Mar '24

Hi Tristan, That worked perfectly - many thanks for your help! Phenix.metal_coordination didn’t like for_phenix.cif file created by Isolde write phenixRsrInput, but I was able to create the edits file by saving the model file as a PDB from ChimeraX directly. Cheers and happy Easter, Taha On 25 Mar 2024, at 16:15, Tristan Croll <tcroll(a)altoslabs.com> wrote: You don't often get email from tcroll(a)altoslabs.com. Learn why this is important<https://aka.ms/LearnAboutSenderIdentification> ***CAUTION:*** This email was sent from an EXTERNAL source. Think before clicking links or opening attachments. Hi Taha, I'm very glad you find ISOLDE useful! Regarding magnesium (and metal ions in general): ISOLDE itself doesn't currently try to write extra Phenix restraints for these, but you can use the program phenix.metal_coordination to generate an edits file that you can add to the phenix.real_space_refine input. That should automatically create a set of bond and angle restraints for all metals in the model. Best, Tristan On Mon, Mar 25, 2024 at 3:46 PM Shahid, Taha (Dr.) via ChimeraX-users <chimerax-users(a)cgl.ucsf.edu<mailto:chimerax-users@cgl.ucsf.edu>> wrote: Dear Tristan, I find ISOLDE invaluable for my work. Not only has it enabled me to build models of the highest quality, but been hugely instructive in giving me an instinctive ‘feel' for protein structure. I am having a minor problem with magnesium ions moving out of density when I run phenix.real_space_refine with settings output by isolde write phenixRsrInput. I typically specify restrainPositions true and includeHydrogens true as well. Is there a way to restrain these ions as well (perhaps an edit I could make to the real_space_refine.eff file)? Many thanks, Taha _______________________________________________ ChimeraX-users mailing list -- chimerax-users(a)cgl.ucsf.edu<mailto:chimerax-users@cgl.ucsf.edu> To unsubscribe send an email to chimerax-users-leave(a)cgl.ucsf.edu<mailto:chimerax-users-leave@cgl.ucsf.edu> Archives: https://mail.cgl.ucsf.edu/mailman/archives/list/chimerax-users@cgl.ucsf.edu/ Altos Labs UK Limited | England | Company reg 13484917 Registered address: 3rd Floor 1 Ashley Road, Altrincham, Cheshire, United Kingdom, WA14 2DT

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change chain description
by Joshua Arribere 27 Mar '24

27 Mar '24

Hello, When I load a pdb into chimerax, a table appears with the chain IDs and associated descriptions. I would like to change the chain descriptions. How do I do that? Thank you, J

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Apple's cpus for trajectory visualisation
by Enrico Martinez 26 Mar '24

26 Mar '24

Dear ChimeraX users ! I wonder about the performance on the modern Apple CPUs: using several Apple's models as a benchmark, I tested Chimera-X on the 2015 and 2017 iMacs equipped with the i7 8 cores and then on the 2023 Macbook Pro equipped with the Apple m2pro chip. In the end, although the modern hardware was much more stable (never mind when loading large netcdf trajectories, as I reported in the case of the 2015 iMAC), I only noticed a slight increase in performance during film editing. As a benchmark, I took a very large model containing the membrane with an embedded oligomer and loaded a trajectory of 5500 frames in Chimera-X. I used surface rendering with 0.4 grid spacing for everything. While everything worked fine, I was able to produce a short 30-second film of 750 frames in about 1h30 on the m2pro, which was almost the same as on my imac 2015. Is there any way to improve the performance of film-making on modern Apple CPUs? Many thanks in advance Enrico

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ChimeraX_question
by 杜博文 26 Mar '24

26 Mar '24

hello,  Chimerax will have an error when we want to use the ribbon inside color white command, please guide me to correct this mistake,Thx. 杜博文南方科技大学/研究生/研究生2021级广东省深圳市南山区学苑大道1088号  

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Re: Chimera X Matchmaker RMSD
by Elaine Meng 25 Mar '24

25 Mar '24

(CC-ing chimerax-users(a)cgl.ucsf.edu since that is the recommended address for ChimeraX questions as long as they do not include private data. Email sent to me directly has more chance of falling through the cracks.) Dear Dr. Sharyn Endow, The Matchmaker algorithm in ChimeraX is the same as in Chimera. So everything I said before about Chimera's Matchmaker is also the case in ChimeraX. If you have the "iteration" option turned on it doesn't use all aligned columns but instead prunes residue pairs for a better fit of the core. If you are showing the sequence alignment, it shows what set of positions were used for the final fit as a light orange colored box. As before, it uses only the CA-CA pairs within those columns, not the side chains. These overall RMSD values are reported in the Log. "pruned" refers only to the fit iteration process, where iteration prunes away some pairs so that they are not used in the final fit. See "Fitting" at the bottom of the "Matchmaker" help: <https://rbvi.ucsf.edu/chimerax/docs/user/tools/matchmaker.html#fitting> Or, if you are using the "matchmaker" or "mmaker" command, see the "cutoffDistance" option for the description of iteration and pruning: <https://rbvi.ucsf.edu/chimerax/docs/user/commands/matchmaker.html#options> If you mean the RMSD header across the top of the sequence alignment, that is a different thing calculated per column (not for the whole structures overall), and you can control in the Sequence Viewer Settings whether this RMSD histogram is calculated CA-only or backbone-only. Neither of them uses the sidechains. If a pairwise alignment, "CA RMSD" boils down to just the CA-CA distance. Simply selecting some range of residues on the sequence alignment doesn't change anything. See help for Sequence Viewer, its header lines, and its Settings: <https://rbvi.ucsf.edu/chimerax/docs/user/tools/sequenceviewer.html> <https://rbvi.ucsf.edu/chimerax/docs/user/tools/sequenceviewer.html#headers> <https://rbvi.ucsf.edu/chimerax/docs/user/tools/sequenceviewer.html#settings> Finally as mentioned in my previous answer about Chimera, you can use the "rmsd" command to calculate RMSDs over any sets of atoms that you choose (with or without sidechains) without changing the current positions of the structures. The more tricky part is that you have to specify in the command which atoms to pair with which atoms, since it is not calculated automatically like it is in Matchmaker. The syntax is a little different than in Chimera: there is a "to" between the two sets of atomspecs, and in ChimeraX the slash symbol "/" is used to indicate chains. "rmsd" command <https://rbvi.ucsf.edu/chimerax/docs/user/commands/rmsd.html> ChimeraX atomspec including many examples: <https://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html> 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 > On Mar 23, 2024, at 8:09 AM, Sharyn Endow, Ph.D. <sharyn.endow(a)duke.edu> wrote: > > Dear Dr Elaine Meng, > > We wrote to you a few years ago regarding Chimera RMSD and you were kind enough to send the information below. We now have a few Q's regarding Chimera X Matchmaker, which displays RMSD values, e.g., when all beta-strands are selected in the Sequence Viewer window. > > • We would like to know what the RMSD values correspond to after aligning two protein sequences using Matchmaker Iwhich uses only only one point per residue for fitting) and selecting all b-strands in the Sequence Viewer window. Is a single RMSD value calculated for each residue to obtain the average RMSD for the "pruned" or all atom pairs and, if so, is the RMSD value between the single point per residue that was used for fitting? > > • Is there some way to obtain the C-alpha RMSD values but not the side chain values, after aligning two protein chains in Matchmaker in Chimera X? > > • What does "pruned" atom pairs mean in this context? > > T > hank you in advance for your help - > > Sincerely, > > Sharyn A. Endow, PhD > Professor of Cell Biology, DUMC > DUS, Cell Biology > PO Box 3709 / 245/247 Sands Bldg / 303 Research Drive > Durham, NC 27710 USA T 919 684-4311 F 919 681-9929 > > > > From: Elaine Meng <meng(a)cgl.ucsf.edu> > Date: January 25, 2021 at 4:26:34 PM EST > To: "Sharyn Endow, Ph.D." <sharyn.endow(a)duke.edu> > Cc: Chimera <chimera-users(a)cgl.ucsf.edu> > Subject: Chimera RMSD > Reply-To: Chimera <chimera-users(a)cgl.ucsf.edu> > > > From: "Sharyn Endow, Ph.D." <sharyn.endow(a)duke.edu> > Subject: Chimera RMSD > Date: January 23, 2021 at 11:27:17 AM PST > > Thank you for your work in developing Chimera. We are trying to use Chimera RMSD to quantitate twisting of a beta-sheet and would like to know what the syntax is to list rmsd values for specified residues corresponding to a beta-strand, not just for single residues. Is it possible to list these values using RMSD? If so, we would greatly appreciate knowing how to get started. > > Sincerely, > Sharyn > > Hi Sharyn, > You can specify any sets of atoms/residues that you like in the RMSD command, as long as there are equal numbers of atoms in the two sets that you specify (from two different models). They will be paired in the order specified. We have a command-line "atom specification" syntax for that kind of thing. There is a longish page with lots of examples here: > <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/frameatom_spec.html > > > In your case, you may need to specify residue numbers, chain ID, and possibly atom names if you just want to use alpha-carbons or backbone as opposed to all atoms of the residues. E.g. something like > > rmsd #0:12.A,57-63.A #1:14.A,59-65.A > > ... for all atoms of model 0 residues 12 and 57-63 in chain A vs. all atoms of model 1 residues 14 and 59-65 in chain A. Or to use CA-only or backbone only: > > rmsd #0:12.A,57-63.A@ca #1:14.A,59-65.A@ca > rmsd #0:12.A,57-63.A@n,ca,c,o #1:14.A,59-65.A@n,ca,c,o > > Of course the numbers could be the same in the two models, I just was trying to give a more general example. > I hope this helps, > Elaine > ----- > Elaine C. Meng, Ph.D. > UCSF Chimera(X) team > Department of Pharmaceutical Chemistry > University of California, San Francisco > > P.S. the chimera-users(a)cgl.ucsf.edu address CC'd here is recommended for general Chimera how-to or is-it-possible types of questions

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isolde write phenixRsrInput (how to restrain ions?)
by Shahid, Taha (Dr.) 25 Mar '24

25 Mar '24

Dear Tristan, I find ISOLDE invaluable for my work. Not only has it enabled me to build models of the highest quality, but been hugely instructive in giving me an instinctive ‘feel' for protein structure. I am having a minor problem with magnesium ions moving out of density when I run phenix.real_space_refine with settings output by isolde write phenixRsrInput. I typically specify restrainPositions true and includeHydrogens true as well. Is there a way to restrain these ions as well (perhaps an edit I could make to the real_space_refine.eff file)? Many thanks, Taha

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ISOLDE query - non crystallographic symmetry?
by Oliver Clarke 25 Mar '24

25 Mar '24

Hi Tristan, I've been using the latest version of ISOLDE with ChimeraX 1.7.1 and it is working beautifully - very smooth simulation and very helpful for fixing up problem areas! One query - is there any support for non crystallographic symmetry in ISOLDE, or if not is this on the roadmap? Thinking both in terms of NCS restraints, but also in terms of propagating edits from one subunit of an oligomer to all the others - this would be very helpful to have for a lot of folks I think, as so many proteins are oligomeric. Thanks for the wonderful piece of software! Cheers Oli

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Difficulty unsubscribing
by BARRY E DEZONIA 25 Mar '24

25 Mar '24

I am trying to leave this email list and currently am unable to. I send email to: chimerax-users-leave(a)cgl.ucsf.edu And it processes and says my email barry.dezonia(a)wisc.edu is not a list member. That is because I signed up with bdezonia(a)wisc.edu.. My mail service treats them as equivalent but it only sends out on the incorrect email address. Can someone unsubscribe ndezonia(a)wisc.edu? I can't figure out how to get my email client to use my other email address as the sending address.

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Adding lipid bilayers to chimerax movie
by Kevin Felt 25 Mar '24

25 Mar '24

Hello ChimeraX Users, I'm trying to make a movie in chimerax involving a membrane protein, and I would like to have some representation of where the inner and outer lipid bilayer leaflets are relative to the protein transmembrane region, ideally represented as phospholipids. Is it possible to do this within Chimerax? I've thought about encoding the movie to mp4 and then figuring out how to simply overlay a bilayer image onto the mp4 where I want with some other software , but I foresee resolution and scaling issues when doing that. Thank you! Sincerely, -- Kevin C. Felt PhD Candidate - Chakrapani Lab Department of Physiology and Biophysics School of Medicine Case Western Reserve University

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