- ChimeraX-users - RBVI Mailing Lists

Greek characters
by Marta Martinez 25 Apr '24

25 Apr '24

Hi guys, I just downloaded a pdb file from AlphaFold DB (AF-P69905-F1-model_v4.pdb). After modifying it with ChimeraX (version 1.6.1 (2023-05-09)) I've saved the modified atomic structure as a cif file. The original pdb file contains this line: COMPND 2 MOLECULE: HEMOGLOBIN SUBUNIT ALPHA; After saving the file as cif format ALPHA is not longer a string but a GREEK character: _entity.pdbx_description "hemoglobin subunit α" Is there any flag in the save command that disables this conversion from plain ASCII to UTF-8? Thank you very much for the answer in advance: MARTA -- Marta Martinez Gonzalez Biocomputing Unit (Lab B13) National Center for Biotechnology-CSIC Darwin, 3. Campus de la Universidad Autonoma de Madrid 28049 Madrid. Spain Tel:+34 915854510 Fax:+34 913720112 E-mail: mmmtnez(a)cnb.csic.es

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atom serial_number is inconsistent with PDB serial numbers in multi-chain structure
by Daniel David Richman 25 Apr '24

25 Apr '24

Hi all, I’ve been debugging an off-by one error in a ChimeraX script I’m working on, which I’ve traced to a apparent inconsistency between the serial_number reported by ChimeraX for an atom and the actual serial number of that atom read/written in PDB format. To reproduce: open 5MJ7 select #1/B:6@CA info atoms sel attribute serial_number ==> atom id /B:6@CA serial_number 2548 but the correct serial number for this atom in 5MJ7.pdb is 2549. Maybe this is because the TER record for chain A takes up one serial number in the PDB file, but ChimeraX doesn’t include it as a numbered atom? Regardless, how can I query ChimeraX for the actual serial number that will be written if I write out a PDB file? Thanks, Daniel

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How to make an MD template for ISOLDE?
by Guillaume Gaullier 25 Apr '24

25 Apr '24

Hi Tristan and chimerax-users, Some time ago I asked the list about modeling PTM and got several helpful answer, including this one: https://mail.cgl.ucsf.edu/mailman/archives/list/chimerax-users@cgl.ucsf.edu… Now, I am working on a structure containing chlorophyll A molecules (residue code CLA) and realized that it won’t work for MDFF in ISOLDE because there is no MD template for it. After trying to manually fit one of these molecules rigidly, I concluded that I would rather spend the rest of the month learning how to make an MD template for it (than next month painstakingly fitting every single molecule manually rigidly). From the message linked above, I think this should be doable because this time it is not a covalent modification on an otherwise parameterized residue, but simply a new ligand (ok, maybe the coordinated Mg2+ makes it a bit more complicated?). I looked up ANTECHAMBER, and also some documentation from OpenMM, but that got me nowhere, mostly because I have little clue what the task really entails. My guess is that I need some program to take the CLA residue in PDB or mmCIF format (which I can easily save from a previous PDB entry) and write out an OpenMM XML file like the one you sent me back then for KCX. Is this correct? The ANTECHAMBER documentation mentions many programs and formats, and I got totally confused. If you have time to elaborate a bit on the specific practical steps to take (including how to supply the final XML file to ISOLDE), that would be super helpful! I can do with pointers to documentation, not afraid to read, but I need help getting oriented. Thank you in advance! Guillaume När du har kontakt med oss på Uppsala universitet med e-post så innebär det att vi behandlar dina personuppgifter. För att läsa mer om hur vi gör det kan du läsa här: http://www.uu.se/om-uu/dataskydd-personuppgifter/ E-mailing Uppsala University means that we will process your personal data. For more information on how this is performed, please read here: http://www.uu.se/en/about-uu/data-protection-policy

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Realsense issues
by Casey Eubanks 24 Apr '24

24 Apr '24

Hey guys, You all helped me a week or so ago getting the Realsense package updated to the new version of chimerax, which I can now download so thats great! But I am now having an issue with running its command "Realsense on" I receive the following errors attached to this email It is having errors processing the trigger and it says it cant resolve the requests. Let me know if I am doing anything wrong or need to make any changes! Thanks, Casey Eubanks Service Desk Specialist MOBILE (205) 617-0581 time zone United States, Central Time Zone (CST) [cid:image001.png@01DA9660.03D4DE80]<https://www.biocryst.com/> "Go Fast, Patients are waiting" If you need immediate IT support please submit a ticket to ITsupport(a)biocryst.com<mailto:ITsupport@biocryst.com> CONFIDENTIALITY NOTICE This email, including any attachments, may contain confidential or legally privileged information that is intended only for the individual or entity to whom it is addressed. If you are not the intended recipient, please be advised that any dissemination, distribution or copying of this email and any attachment is strictly prohibited. If you have received this email in error, please reply to the sender so that BioCryst Pharmaceuticals, Inc. can take corrective measures and then permanently delete this email and any attachment, including any printed copies. Thank you.

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Finding unmodeled blobs in a map
by Guillaume Gaullier 24 Apr '24

24 Apr '24

Hello, With `volume zone` I can show the parts of a map close to an atomic model. Is there a way to do the opposite, i.e. show only the parts of a map that don’t enclose any atoms? This would be already very helpful only as a visualization. But even better would be a way to build a list of markers at the centroids of such unmodeled blobs, to easily navigate to them. Or maybe this is too narrow in scope and better left to ISOLDE? (Sorry Tristan… more feature suggestions…). Thank you, Guillaume När du har kontakt med oss på Uppsala universitet med e-post så innebär det att vi behandlar dina personuppgifter. För att läsa mer om hur vi gör det kan du läsa här: http://www.uu.se/om-uu/dataskydd-personuppgifter/ E-mailing Uppsala University means that we will process your personal data. For more information on how this is performed, please read here: http://www.uu.se/en/about-uu/data-protection-policy

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Adding missing atoms of the DNA structure
by Enrico Martinez 24 Apr '24

24 Apr '24

Dear Chimera-X users I am preparing the structure of the protein-DNA complex for molecular dynamics simulation with Amber. This is the original pdb: https://www.rcsb.org/structure/5FKW When I try to parametrize it the tleap shows the following error because of the absence of some atoms from the phosphate: FATAL: Atom .R<DG5 733>.A<P 32> does not have a type. FATAL: Atom .R<DG5 733>.A<OP1 33> does not have a type. FATAL: Atom .R<DG5 733>.A<OP2 34> does not have a type. FATAL: Atom .R<DG5 758>.A<P 32> does not have a type. FATAL: Atom .R<DG5 758>.A<OP1 33> does not have a type. FATAL: Atom .R<DG5 758>.A<OP2 34> does not have a type. Would it be possible to use some commands of the Chimera-X to automatically repair this part of the DNA by adding missing atoms ? Thank you in advance ! Enrico

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Cutting out an asymmetric unit from the map
by Das, Abhinaba 23 Apr '24

23 Apr '24

Hi! I was wondering if there is a sequence of commands one could use to extract an asymmetric unit from the original map after roughly fitting the model into it. The positions of these extracted maps should of course be preserved and should on the same grid. One can then better fit the model in this extracted ASU density. Thanks in advance for any guidance. Abhi

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Lighting options in ChimeraX
by Elaine Meng 22 Apr '24

22 Apr '24

> On Apr 20, 2024, at 7:36 PM, Friedman, Simon <friedmans(a)umkc.edu> wrote: > > I am working on mol graphics for a figure. I'm using both chimera-x and chimera. I'm trying to figure out if chimera-x has a set of functionality that chimera has. Specifically in chimera I was able to move light sources around, change intensity, shinyness etc. Also I was able to use ray tracing in the output. In chimera-x I can't find any menu for moving light sources around etc. One very cool thing that is there is the 'soft' lighting option which gives a very cool surface to the carbon atoms. So I was wondering if there were more options for messing with lighting etc in chimera-x? > Thank you! > > Cheers, > Simon > > Simon H. Friedman, Ph.D. > UM Curators' Distinguished Professor > Division of Pharmacology & Pharmaceutical Sciences > University of Missouri, Kansas City Hey Simon! ChimeraX does not have ray-tracing, but as you discovered with the ChimeraX "soft" lighting (sugar cube icon in the toolbar), it does have ambient-occlusion lighting simulated by multiple multidirectional light sources, which Chimera does not have. The rest of this description pertains to ChimeraX: When you try the different lighting icons in the toolbar, the corresponding command is shown in the Log. So that should help you learn some of the common options. However, there are lots more options available with the commands than are represented by toolbar icons. (1) the "lighting" command has the presets including soft, but also options for intensities, colors and directions of the directional lights (key light and fill light), depth cueing, and shadows, among many other things. There is no GUI for changing the direction interactively, however. See the "lighting" manpage and many options explained therein. It also shows pictures of the relevant icons from the toolbar. <https://rbvi.ucsf.edu/chimerax/docs/user/commands/lighting.html> (2) the "graphics" command has options for background color, silhouette edges (the outlines that are usually black), and triangulation fineness of atom/bond/ribbon representations, see: <https://rbvi.ucsf.edu/chimerax/docs/user/commands/graphics.html> (3) the "material" command has control over shininess of objects <https://rbvi.ucsf.edu/chimerax/docs/user/commands/material.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

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Running AlphaFold through Chimerax vs. Colab directly
by Coyle, Maxwell C 22 Apr '24

22 Apr '24

Hello! I’ve been predicting structures recently using the AlphaFold tool through ChimeraX (which directs to the alphafold21_predict_colab.ipynb notebook), but I’ve noticed I get often quite different results when I run the same prediction through the AlphaFold.ipynb notebook directly in Colab. I was wondering if anybody could point me to the major differences between these two implementations? Are they searching different libraries to generate a multiple sequence alignment? Are they using different numbers of iterations or energy minimization strategies? Thanks for any guidance, Max Max Coyle, PhD Postdoctoral Fellow, Bellono Lab Dept of Molecular and Cellular Biology Harvard University mcoyle(a)fas.harvard.edu

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transform coordinates of an atomic model
by Engeholm, Maik 22 Apr '24

22 Apr '24

Hi Tom, hi Eric, thanks a lot for answering my previous question so comprehensively! Hope it's OK to bother you again. This is about something completely unrelated. I would like to apply a transformation (rotation plus translation) to an atomic model. I need to change the coordinates of the model relative to the overall coordinate system. Changing the scene or camera coordinates is not an option, since in the end I want to place multiple copies of my model (in this case a nucleosome) in a specific orientation relative to each other (i.e. within the same coordinate system) to model an array of nucleosomes. If I remember correctly, back in Chimera this could be achieved with "model.openState.global/localXform(transformation)" where transformation was an chimera.Xform object. But as far as I can see this is not supported in chimeraX. Here is a reproducible example of the simplest case, in which I define the center and two (roughly) orthogonal axes of my atomic model (i.e. the normal of the DNA superhelix and the dyad axis) and try to map those onto the origin of the coordinate system and two unit vectors. """ from chimerax.core.commands import run import numpy as np from numpy import cross, dot np.set_printoptions(suppress = True) run (session, 'close session') run (session, 'windowsize 360 360') target_centre = np.array((0, 0, 0)) target_normal = np.array((0, 1, 0)) target_dyad = np.array((0, 0, 1)) target_3rd_axis = cross(target_normal, target_dyad) run (session, 'open 3lz0 name 3lz0') pdb3lz0_DNA_plane = run (session, 'define plane #1/I,J:-56-56') pdb3lz0_DNA_centre = run (session, 'define centroid #1/I,J:-56-56') pdb3lz0_dyad_base_pair = run (session, 'define centroid #1/I,J:0') pdb3lz0_dyad_axis = run (session, 'define axis #1.4 #1.5') pdb3lz0_centre = session.models[3].xform_center pdb3lz0_normal = session.models[3].xform_normal pdb3lz0_dyad = session.models[6].xform_direction pdb3lz0_3rd_axis = cross(pdb3lz0_normal, pdb3lz0_dyad) rotation_inverse = np.c_[pdb3lz0_3rd_axis, pdb3lz0_normal, pdb3lz0_dyad] rotation = np.linalg.inv(rotation_inverse) translation = -pdb3lz0_centre transformation = np.c_[rotation, translation] print(session.models[0].position.matrix) """ At this point I have tried to modify the position.matrix with "session.models[0].position.matrix = transformation" but this gives me an "AttributeError: property 'matrix' of 'Place' object has no setter". I'm sure there must be a way to transform an atomic model in this way and would be really grateful for your help. Thanks a lot in advance, Maik

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