July 2021 - ChimeraX-users - RBVI Mailing Lists

Re: [chimerax-users] command line way for inverting selection
by Rangarajan, Amith 29 Jul '21

29 Jul '21

Hi, I am looking for a way to invert selection without reaching for the tool bar. I would like to know if there is a way to invert selection via the select command ( or some other command) thanks a lot, Amith

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ATOM has no alt loc B
by James Loy 28 Jul '21

28 Jul '21

Hi folks- I'm trying to add hydrogens to an mmCIF file (5byl) using the addh command. However, every time I try, I encounter the following error: Traceback (most recent call last): File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/ChimeraX_main.py", line 712, in init run(sess, cmd) File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/core/commands/run.py", line 36, in run results = command.run(text, log=log, return_json=return_json) File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/core/commands/cli.py", line 2852, in run result = ci.function(session, **kw_args) File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/addh/cmd.py", line 63, in cmd_addh add_h_func(session, structures, template=template, in_isolation=in_isolation, **prot_schemes) File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/addh/cmd.py", line 170, in hbond_add_hydrogens add_hydrogens(session, atoms, type_info_for_atom, naming_schemas, hydrogen_totals, File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/addh/hbond.py", line 214, in add_hydrogens _attach_hydrogens(atom, altloc_hpos_info, bonding_info) File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/addh/hbond.py", line 895, in _attach_hydrogens add_altloc_hyds(atom, altloc_hpos_info, invert, bonding_info, total_hydrogens, naming_schema) File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/addh/cmd.py", line 862, in add_altloc_hyds h = new_hydrogen(atom, i+1, total_hydrogens, naming_schema, File "/usr/lib/ucsf-chimerax/lib/python3.8/site-packages/chimerax/addh/cmd.py", line 882, in new_hydrogen metal_pos = metal.get_alt_loc_coord(alt_loc) File "atomic_cpp/cymol.pyx", line 587, in chimerax.atomic.cymol.CyAtom.get_alt_loc_coord ValueError: Atom /A MG 702 MG has no alt loc B I'm using ucsf-chimerax_1.2.5-1_amd64.deb installed on Ubuntu 20.04. I've done some digging, and I cannot figure out what is going on. Any help would be appreciated. Thanks in advance! -James -- James Loy, Ph. D. 614.915.9792 LinkedIn <https://www.linkedin.com/in/james-m-loy-ph-d-ba2256a/>

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The PDB code for the demo picture on the website
by BAOCHENG LIU 28 Jul '21

28 Jul '21

Hi chimerax group, I am a postdoc in UCLA using chimerax. Thanks for providing all scientists this powerful software that makes life easier. I have a question here when I was learning the cartoon/ribbon style command line. So, I saw the 4 demo pictures on the website https://www.rbvi.ucsf.edu/chimerax/docs/user/commands/cartoon.html#style and just realized the structure just looks similar to one of my structures. Could you please tell me the PDB code for that structure so I can compare it with mine in detail? Hope it is released. Thank you. Best regards, Baocheng

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resfit command for nuclei acid
by Wen-Jin Winston Wu 27 Jul '21

27 Jul '21

Hi Tom, I have just tried to use the "resfit" command ChimeraX Does the nice command of "resfit" in ChimeraX support inspection on nuclei acid? It seems that it only support protein residues as with the command " resfit #1/D:DT map #3", it returned with the message that "None of the 9 specified residues have backbone atoms N, CA and C". I have not checked out the daily build version yet, but thought that I can ask first. Thanks, Best wishes, Winston

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Custom colour for atoms with bfactor==0
by Lorena Zuzic 27 Jul '21

27 Jul '21

Hi, I wanted to know if there is a way of colouring my structure by bfactor, but with an additional condition where all bfactor==0 atoms are coloured in grey. Currently, I am using a white to red gradient for my B-factors: color bfactor range -2.2, 2.2 In this case, bfactor==0 values are coloured white. However, I would like them to be grey and outside the gradient (as they represent an unmapped portion of the protein). Thanks! Lorena

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create mask from "shapes"
by Roberto Marabini 27 Jul '21

27 Jul '21

Hi, It is possible to create a mask from a shape?. For example from the result of "*shape icosahedron".* If the command does not exist I guess I may create it as follows * the input would be the 3D map to be masked and the shape to be used as mask * request all the (varray, tarray) from the shape. * from varray,tarray build the triangles that define the surface of the shape * for each triangle create the normal vector * multiply each normal vector by the position of each voxel (dot product) * keep those voxels that have negative dot products for all the triangles. thanks for the help

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Automated Fitting of models into maps and saving fits with a correlation score > X
by Vorländer,Matthias Kopano 26 Jul '21

26 Jul '21

Dear all, I have a set of 100 “artificial” tomograms, each containing approx 100 copies of a simulated density map of my protein of interest. I would like to fit each tomogram with the PDB of my POI, and save copies for all fits with a correlation score > 90%. Using the fitmap command in Chimera and then manually selecting the fits that meet the criterium works, but takes quiet a long time for a larger amount of data. I wonder if this could be automated, and if somehow would be able me to put together a script (is it possible to execute such tasks in a non-gui way, by submitting it to a cluster so that it could be parallelized?). Thanks a lot in advance, Best, Matthias

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unexpected behavior of build start
by Alexis Rohou 26 Jul '21

26 Jul '21

Hi ChimeraX team, I'm running into unexpected behavior when using the build tool. Here's what I'm doing: - open map --> model #1 - open PDB --> model #2 - fit #2 in #1 (the PDB moves by ~20 Å at this step) - cofr centerOfView showPivot true - move the view around so that the pivot axes intersect where I want to place a new atom - build start atom #2 expected result: a new H atom is created exactly at the center of view (where the pivot axes intersect) actual result: the new H atom is created some distance away; I think the vector from where the new H atom is built to the cofr is the same vector as the PDB model was displaced by the fitting into the map (my second step, above), but I haven't checked that carefully. Is this what is expected? It confused me :) Is there a command I can use to move the atom to the correct location after it's been created? Interestingly, if I add a H atom into a new model, then it appears where I expect it, at the cofr: - build start atom "custom built" This is with 1.2.5 (2021-05-24) Cheers, Alexis

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question
by 王镐锋 26 Jul '21

26 Jul '21

Dear guys, Sorry to disturb you guys. When I use the UCSF ChimeraX, I try to define the second structure for part of model. I type the command like "dssp (#1 & sel) energy cutoff 0.5 minheliexlen 3", it works for the whole model instead of what I choose specially. Could you please help me? Thanks so much! Best, Haofeng Wang Ph.D student Tianjin University, China

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measure volume in ChimeraX
by Andrew Blyth 24 Jul '21

24 Jul '21

Hi, I am having trouble getting the ‘measure volume’ and ‘measure area’ command to work in chimera. I have been trying the command: measure volume #3/A:457 for the structure that I have been using, however, nothing happens when I execute this command. Could you please provide me with an example command that will work for measuring the volume or area of a residue? Thanks, Andrew Blyth PhD Candidate Medical Biochemistry - Flinders University Room 6E109 Flinders Medical Centre | South Australia 5001, Australia Phone: +61 8 8204 5098 | E: andrew.blyth(a)flinders.edu.au<mailto:andrew.blyth@flinders.edu.au>

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