- ChimeraX-users - RBVI Mailing Lists

Adding a label to MRC map file header
by Tom Goddard 03 Dec '24

03 Dec '24

Hi Raman, I'm not sure where in the MRC binary file this "EXPDATA EM" is suppose to go, maybe a "label" field. As you can see from the MRC file spec it has space for 10 labels in bytes 225-1024 of the header https://www.ccpem.ac.uk/mrc_format/mrc2014.php ChimeraX has no options to insert specified text into those labels, but you could edit the ChimeraX Python code that writes the MRC file to add a label. The file is called writemrc.py and is in your ChimeraX distribution, on Mac it is here ChimeraX.app/Contents/lib/python3.11/site-packages/chimerax/map_data/mrc/writemrc.py Here's what this code looks like in the ChimeraX Github repository https://github.com/RBVI/ChimeraX/blob/00c7ef34fdf8e3f9675cf892f346adbecbfe6… It has some lines that put a ChimeraX version and time stamp into the MRC file ver_stamp = 'ChimeraX %s %s' % (version, asctime()) labels = [ver_stamp[:80]] You could add a line after that labels.append('EXPDATA EM') to add a label with that string. then restart ChimeraX and save a map (e.g. command "save mymap.mrc"). Another approach would be to open the mrc file in a binary editor and carefully modify some of the bytes from 225-1024 to add your label. Of course all this assumes that EXPDATA EM is supposed to go in a label and not for instance the EXTRA bytes part of the header. It seems absurd that you have software that won't work without a special label in the file. Tom > On Dec 3, 2024, at 4:47 PM, Raman, C.S. <craman(a)rx.umaryland.edu> wrote: > > Hi Tom, > > Is there an easy way to insert into the header of an MRC file the descriptor "EXPDATA EM" as done by the PDB? I need to do this to run a validation program but don't quite know how to go about it. > > Any help would be greatly appreciated. > -raman

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Re: [Chimera-users] Movie from pdb file with 30 models of a conformational change.
by Elaine Meng 02 Dec '24

02 Dec '24

Hi Evan, Your image looks nice! From your screenshot I can see you are using ChimeraX (not Chimera) so I will answer for ChimeraX ( there is a different email address for ChimeraX questions, chimerax-users(a)cgl.ucsf.edu CC'd here). To "play" the conformational change there are a couple of options: (1) if the models are already open as a set of multiple models as shown in your screenshot, you can use command: mseries slider #1 ...which will open a slider interface that you can click play, record movie, etc. Or, you can play through the series with the "mseries" command. <https://rbvi.ucsf.edu/chimerax/docs/user/commands/mseries.html> (2) Or, you can use the "coordsets true" option of the "open" command when opening the file, <https://rbvi.ucsf.edu/chimerax/docs/user/commands/open.html#coordsets> which means to interpret the file as a single trajectory instead of a series of models. That will automatically show a slider interface. Example: open blahblah.pdb coordset true If you want to use the file browser to find your PDB file, you can use command open browse coordsets true ...and it will open the file browser for you to find and choose the file. If you have a trajectory, you can also play through it with the separate "coordset" command. <https://rbvi.ucsf.edu/chimerax/docs/user/commands/coordset.html> More info, general explanation of model series vs. trajectories <https://rbvi.ucsf.edu/chimerax/docs/user/trajectories.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 Dec 2, 2024, at 1:31 PM, Evan Kantrowitz via Chimera-users <chimera-users(a)cgl.ucsf.edu> wrote: > > Hi, > > Can someone give me help with a, I think, simple issue. I have a single pdb file containing 30 MODELS > These 30 models correspond to a conformational change. Here is a portion of the Models list > > When I read it in,I see all 30 models showing in the view. > What I want to do is make a movie showing these 30 MODELS one after the other. I have tried coordset and coordset slider but have not got it to work. > > Thanks > > Evan > > PS. This is what the image looks like with the 30 frames.It was generated from the A chain of pdb files 2e2n and 2e2q using the website ViewMotions (viewmotions.bc.edu) > > > ----------------------------------------------------------------------------- > Evan R. Kantrowitz, Ph.D evan.kantrowitz(a)bc.edu > Emeritus Professor of Chemistry Cell: 617-775-9915 > Boston College www2.bc.edu/evan-kantrowitz -----------------------------------------------------------------------------

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ChimeraX-1.8 functionality regarding the match command
by Nicholas Ferraro 02 Dec '24

02 Dec '24

Good morning, My name is Nicholas Ferraro. I am a graduate student at the City College of New York. I am currently using ChimeraX-1.8 to visualize multiple PDBs of the hexameric helicase I am working with. We have labeled each protomer of the hexamer A-F. I understand the software allows for matching structures either by best-aligning pair of chains, a specific reference structure to the best-aligning chain, and specific chains in a reference structure with specific chains in the matching chain. I have six PDBs. What I want to do is align all chains with respect to their chain ID and specific sequence. Can you advise on how to accomplish this in chimera-1.8? Thank you for you assistance. Please let me know if you need more details. Best, Nicholas Ferraro

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Stepping through model in secondary structure element steps (ISOLDE)
by Vorländer,Matthias Kopano 28 Nov '24

28 Nov '24

Dear all, I seem to remember that it was possible to step through a model in Isolde one secondary structure element at a time, however I don't find that option anymore. Is this possible at all? I prefer this to the isolde step option that goes through the model one residue at a time. Many thanks in advance, Matthias Sent from Outlook for Android<https://aka.ms/AAb9ysg> --- Matthias Kopano Vorländer Postdoc matthias.vorlaender(a)imp.ac.at<mailto:matthias.vorlaender@imp.ac.at> Plaschka Lab IMP - Research Institute of Molecular Pathology - imp.ac.at<https://imp.ac.at/> Part of Vienna BioCenter. www.viennabiocenter.org<https://www.viennabiocenter.org>

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Re: IMOD Segmentation to ChimeraX (.mod to .cmm Conversion)
by Tom Goddard 27 Nov '24

27 Nov '24

Glad you got it to work. Tom > On Nov 27, 2024, at 3:30 PM, LENKA MILOJEVIC <lenka11(a)g.ucla.edu> wrote: > > Dear Dr. Goddard, > > Thank you so much! That worked! I thought I’d have to produce a .cmm file or mask the map using the volume tool and the .mod file as a surface. > > I really appreciate your swift responses! This was incredibly helpful. > > Have a great rest of your day! > > Sincerely, > Lenka > > On Wed, 27 Nov 2024 at 15:26, Tom Goddard <goddard(a)sonic.net <mailto:goddard@sonic.net>> wrote: >> Hi Lenka, >> >> Seems like you got what you wanted "I was wondering if there's any way that I could convert the .mod file into a .cmm file because my goal is to segment a map in ChimeraX using the Color Zone tool, according to the contours from IMOD." Your image shows the traced curves as connected markers (fake atoms connected by bonds). To color the nearby density you would then use the Color Zone tool, menu Tools / Volume Data / Color Zone and it has a Split Map button that would let you make a new map that includes just the colored part near your curves. The equivalent ChimeraX command is "color zone" >> >> https://www.cgl.ucsf.edu/chimerax/docs/user/commands/color.html#zone >> >> If the command syntax is confusing just use the graphical Color Zone tool and it will log the equivalent command to the Log panel and you will have a better idea of how to type a command if you want to use some of the fancier options (like bondPointSpacing) that the graphical tool does not offer. >> >> Tom >> >> >>> On Nov 27, 2024, at 2:46 PM, LENKA MILOJEVIC via ChimeraX-users <chimerax-users(a)cgl.ucsf.edu <mailto:chimerax-users@cgl.ucsf.edu>> wrote: >>> >>> In the event that I want to mask map #3 using the .mod file in #1 , which command exactly do I run? I'm attaching a screenshot showing my current session. >>> <image.png> >>> >>> >>> On Wed, Nov 27, 2024 at 2:42 PM LENKA MILOJEVIC <lenka11(a)g.ucla.edu <mailto:lenka11@g.ucla.edu>> wrote: >>>> Hi Elaine, >>>> >>>> If I don't input contours true, nothing shows up on my screen. It just states it read it. >>>> open <> C:/Users/lenkamilojevic/Box/HSV-1/Front/HSV1_9_overcoils.mod >>>> Read IMOD model C:/Users/lenkamilojevic/Box/HSV-1/Front/HSV1_9_overcoils.mod, pixel size 0.568 >>>> >>>> Sorry for the trouble. I really appreciate your help. >>>> >>>> Best, >>>> Lenka >>>> >>>> On Wed, Nov 27, 2024 at 2:09 PM Elaine Meng <meng(a)cgl.ucsf.edu <mailto:meng@cgl.ucsf.edu>> wrote: >>>>> Hi Lenka, >>>>> Contours true is to make it into markers and links (fake atoms and bonds) instead of a surface. You do not need markers and links for masking, you only need a surface model (meshes true contours false). >>>>> >>>>> Just open the file directly without any options and by default it should make a surface model that you can use in "volume mask" - I thought "meshes true" would still make the surface but maybe it only does that when contours is false. >>>>> >>>>> I'm sorry I mentioned the contours option since it was confusing... I only did so because at first I thought you wanted markers. >>>>> >>>>> 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 Nov 27, 2024, at 1:34 PM, LENKA MILOJEVIC via ChimeraX-users <chimerax-users(a)cgl.ucsf.edu <mailto:chimerax-users@cgl.ucsf.edu>> wrote: >>>>> > >>>>> > Dear Dr. Meng, >>>>> > >>>>> > Thank you! I've now managed to open the segmentation with open C:Path format imod meshes true contours true. But If I run volume mask it just outputs: >>>>> > volume mask #3 surfaces #1 fullMap true >>>>> > No surfaces specified >>>>> > volume mask #3 #1 extend 3 >>>>> > Missing required "surfaces" argument >>>>> > volume mask #3 surfaces #1 >>>>> > No surfaces specified >>>>> > >>>>> > Any advice? Is the contour not actually a surface yet? Or am I writing the command wrong. >>>>> > >>>>> > Thank you so so much! >>>>> > >>>>> > Best, >>>>> > Lenka >>>>> > >>>>> > On Wed, Nov 27, 2024 at 1:45 PM Elaine Meng <meng(a)cgl.ucsf.edu <mailto:meng@cgl.ucsf.edu>> wrote: >>>>> > Hi Lenka, >>>>> > The link that you sent is to the Chimera documentation (not ChimeraX): >>>>> > <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/filetypes.html#object> >>>>> > >>>>> > Since they are different programs, there are differences... but not in this case! ChimeraX can also open these IMOD segmentations: >>>>> > <https://rbvi.ucsf.edu/chimerax/docs/user/commands/open.html#segmentation> >>>>> > <https://rbvi.ucsf.edu/chimerax/docs/user/formats/imod.html> >>>>> > >>>>> > These segmentation models are surfaces, not the atoms or pseudoatoms (markers) that you would need to define a zone with Color Zone. Although the second link above explains that you can make the IMOD surface mesh into markers/links by opening the file with the "open" command option "contours false," that is unlikely to make them suitable for defining zones. Mainly it is used to improve display. >>>>> > >>>>> > Instead you can use "volume mask" to mask parts of your map with the IMOD segmentation surfaces. >>>>> > <https://rbvi.ucsf.edu/chimerax/docs/user/commands/volume.html#mask> >>>>> > >>>>> > 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 Nov 27, 2024, at 11:56 AM, LENKA MILOJEVIC via ChimeraX-users <chimerax-users(a)cgl.ucsf.edu <mailto:chimerax-users@cgl.ucsf.edu>> wrote: >>>>> > > >>>>> > > Dear Sir or Madam, >>>>> > > >>>>> > > While the 'Input File Types' page lists .mod and .imod files under 3D objects ChimeraX can open, when I try to open a .mod file (e.g., run command open C:/*PathToFile* or through the GUI), the file doesn't show up even though the log output states 'Read IMOD model C:/*PathToFile*, pixel size X'. >>>>> > > >>>>> > > I was wondering if there's any way that I could convert the .mod file into a .cmm file because my goal is to segment a map in ChimeraX using the Color Zone tool, according to the contours from IMOD. >>>>> > > >>>>> > > I appreciate your time and assistance! >>>>> > > >>>>> > > Sincerely, >>>>> > > Lenka >>>>> > >>>>> > _______________________________________________ >>>>> > 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/ >>>>> >>> _______________________________________________ >>> 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/ >>

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IMOD Segmentation to ChimeraX (.mod to .cmm Conversion)
by LENKA MILOJEVIC 27 Nov '24

27 Nov '24

Dear Sir or Madam, While the 'Input File Types' page <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/filetypes.html> lists .mod and .imod files under 3D objects ChimeraX can open, when I try to open a .mod file (e.g., run command open C:/*PathToFile* or through the GUI), the file doesn't show up even though the log output states 'Read IMOD model C:/*PathToFile*, pixel size X'. I was wondering if there's any way that I could convert the .mod file into a .cmm file because my goal is to segment a map in ChimeraX using the Color Zone tool, according to the contours from IMOD. I appreciate your time and assistance! Sincerely, Lenka Lenka Milojević Biophysics PhD Candidate Z. Hong Zhou Lab University of California, Los Angeles

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Closest distance list between residues/atoms; And selecting first/last residue in a chain
by pm676＠cam.ac.uk 27 Nov '24

27 Nov '24

Hi Is there a way by command line to generate a list of residue to residue (or atom to atom) distances ranked by closest to furthest, for say, all residues within 4A of each other at an interface between two protein chains? Can it also state the type of interaction, e.g. salt bridge, H-bond, vdW? Also, completely separately, is there a way by command line to select the first and last residue in a chain (without having to find their number)? No worries if not. Thanks so much! Cheers, Paul

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Visualization of methyls rotations
by Enrico Martinez 27 Nov '24

27 Nov '24

Dear ChimeraX users! In visualizing the MD trajectory, I noticed a small issue with the depiction of the rapid rotations of the ligand's methyl groups. Specifically, the hydrogens appear to periodically collapse into a singularity before returning to their expected positions. Could this be addressed through additional post-processing of the trajectory data? Many thanks in advance Enrico

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Question about using AF3-competitor outputs
by David S. Fay 26 Nov '24

26 Nov '24

Hi, Apologies if this already came up and I missed it. I just ran a few dimer models on the Chai Discovery website (https://lab.chaidiscovery.com/dashboard) and it seems to work quite well. However, when I tried to upload the relevant json file using the Structure Prediction - AlphaFold Error Plot pulldown menu, ChimeraX failed to recognize the file. I tried a few other files and something similar happened. Do you know of a workaround or is this something that is likely to get patched soon? I should mention that Chai may be putting the relevant PAE information into a “npy" file, (e.g., pae.model_idx_0.rank_1.npy) based on the size of that file, and I haven’t yet tried to convert npy to a json or know if that’s even possible. I also wonder if Boltz-1, another AF3 competitor, will have different outputs as well. They don’t seem to have a GUI yet and perhaps they won’t, so I haven’t been able tyo test this yet. I assume this has all been topic of discussions at ChimeraX though… Thanks in advance for your help! David David S. Fay Ph.D. Professor, Department of Molecular Biology Associate Director, National Institutes of Health Wyoming INBRE University of Wyoming email: davidfay(a)uwyo.edu

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How to remove specific H bonds
by Sen, Anindito 26 Nov '24

26 Nov '24

Dear ChimeraX group, How do I remove certain 'H' bonds from an atomic model, leaving the important 'H' bonds Regards Stay safe & Regards Anindito Sen. Ph.D

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