February 2023 - ChimeraX-users - RBVI Mailing Lists

Question!
by Matthew Wengler (TSL) 26 Feb '23

26 Feb '23

Hello, I am a PhD student studying the downstream signalling events of a kinase in a fungal plant pathogen. We have differential phosphopeptide data of the kinase itself over a time course during plant infection (i.e., four residues on this kinase are differentially phosphorylated during stages of infection). I had a vision of showing a movie that incorporated the phosphorylated residues x phosphorylation abundance x time on the kinase’s tertiary structure and was wondering if this could be possible with Chimera X: * The tertiary structure would be displayed in grey * The phosphorylated residues would be highlighted in blue * A movie would be played and the highlighted residues would change colour based on phosphopeptide abundance over a time course (ranging from 0-100% abundance = blue -> red) I was wondering if this was currently possible. Alternatively (and maybe this is really the easiest way), because we only have ~6 time points, I could have 6 different stills of the protein with the residues highlighted corresponding to the phosphopeptide abundance values (blue-red 0-100%) and then piece them together in a 6 frame video that will loop…? I think I would prefer the colours to blend slower together dynamically than 6 harsh frames. Would there be a way to do this in Chimera? Thank you, Matt Wengler

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some question about the use of chimera x 1.4
by 游宠昭 24 Feb '23

24 Feb '23

Dear developers, Sorry to bother you. Recently, I notice that chimera x display the DNA/RNA in a different way from that in chimera, and I find that there is a option in chimera called ribbon spline containing two options:B-spline and cardinal which explain why DNA/RNA is displayed in different ways in two softwares. However, I can not find the related actions in chimera x: "ribbon spline" in chimera refers to what in chimera x and how can I adjust this parameter. Sincerely, Chongzhao You

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Help Generating a Volume to use for 2D classification template generation
by Joshua Denson 22 Feb '23

22 Feb '23

Hi, I’m trying to take an alpha fold model of my complex, generate a low resolution map of the model using molmap, and then use it for 2D template generation in CryoSparc. I am able to generate the low resolution map just fine, but the resulting map is in a rectangular volume (48x64x51) and I need it to be a cubic volume for CryoSparc to accept it. Ideally it would have dimensions of 64x64x64. Is there a way to generate a low resolution map in a cell with specific dimensions while maintaining the protein complex dimensions? (eg. I don’t want to simply scale it into a cube) I am using ChimeraX 1.5. Best Josh Joshua M. Denson PhD Candidate (Johnson Group) Dept. of Chemistry and Biochemistry Utah State University

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Matchmaker on a subset of residues
by McClean, Phillip 22 Feb '23

22 Feb '23

Is it possible to use the Chimerax Matchmaker command to obtain the RMSD value between a subset or residues between two different proteins. Phil McClean

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Custom Toolbar Button
by Dominik Sordyl 22 Feb '23

22 Feb '23

Hi, Is there a possibility to add a button to the "File" section on the toolbar? I have installed custom plugin and it can be run from Tools --> General section, but I am wondering if there is a way to add a shortcut button to the toolbar. Best, Dominik

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Making a movie from a group in PDB file
by Aleksandar Donev 21 Feb '23

21 Feb '23

Hi, I am trying to create a simple animation of a demo molecular dynamics program https://github.com/stochasticHydroTools/DemoMD using either chimerax or chimera. The code creates a .pdb file that has multiple time frames in it, which show up in chimerax as a "group". How do I make chimera show the frames one by one and then make a movie out of that or save each frame as an image? I used to be able to do that in chimera but either the interface has changed or I have forgotten. I found lots of instructions about how to make movies by manipulating one data set (say rotating a molecule) but could not find anything about animation in time. Thanks, Aleks -- Aleksandar Donev, Professor of Mathematics Courant Institute of Mathematical Sciences Office: 1016 Warren Weaver Hall, New York University E-mail: donev(a)courant.nyu.edu Phone: (212) 992-7315; Fax: (212) 995-4121 Mailing address: 251 Mercer St, New York, NY 10012 Web: http://cims.nyu.edu/~donev

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Distance maps and all atom distances
by André Graça 17 Feb '23

17 Feb '23

Hi everyone! Does ChimeraX have a tool to calculate distance maps in the same fashion as Chimera does with RRDistMaps? I believe Chimera's RRDistMaps only calculates intermodal distances between C-alpha atoms. Does anyone know a tool or have a script that could calculate all atom distances from two sequence identical models? Cheers, André

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Image saving/exporting options
by Matthew Graneri 16 Feb '23

16 Feb '23

Hi there, I was wondering if there was an option to set the resolution of an image you want to export? In the older Chimera application, there were many more options open to you when you wanted to save an image (I’ve attached a screenshot of the old and new image saving screens for comparison). If not, is there any chance of implementing a resolution specification option sometime in the future? I was also wondering if it was possible to save images from ChimeraX as PDF files? I find that they usually maintain a high resolution without being particularly big, in terms of memory. Apart from that, really enjoying ChimeraX! Regards, Matthew

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Loading MTZ data - volume is restricted to a small sphere within the protein model
by Lewis James martin 15 Feb '23

15 Feb '23

Hi folks, I recently installed Clipper, and on loading some example PDB and MTZ data, I'm seeing just a sphere of density data that does not cover the full protein model. This behaviour is not restricted to a single example. Is it expected? The example files I used are in 6DIL <https://www.rcsb.org/structure/6DIL>. I downloaded "PDB Format" and "Map Coefficients (MTZ Format)" from the drop-down menu. Loading the PDB by drag-and-drop into ChimeraX works as expected (coordinates do show). On loading the MTZ by drag-and-drop, and selecting the PDB model to import data into, I see the below representation. The density does not cover the full set of protein coordinates - it's limited to a sphere within the protein. Curiously, I saw this on coot too - so maybe I'm just getting the options incorrect? I did try shifting the cutoffs in the "Volume Viewer" Tool, and the mesh does change but it's still limited to this sphere. Changing from a mesh surface to "Maximum" shows that the available data is limited to a cube that does not cover the protein. Is there a way to view the full density? Out of interest, I also tried generating the mesh myself, but only got halfway. This at least shows that the data does cover the whole protein: import gemmi import numpy as np import meshplot as mp from skimage.measure import marching_cubes #run 'gemmi mtz2cif 6dil_phases.mtz 6dil_phases.cif' first doc = gemmi.cif.read('/Users/ljmartin/Desktop/6dil_phases.cif') rblocks = gemmi.as_refln_blocks(doc) rblock = rblocks[0] size = rblock.get_size_for_hkl(sample_rate=2.6) full = rblock.get_f_phi_on_grid('pdbx_FWT', 'pdbx_PHWT', size) array = np.array(full, copy=False) complex_map = np.fft.ifftn(array.conj()) scale_factor = complex_map.size / full.unit_cell.volume real_map = np.real(complex_map) * scale_factor v,f,n,_ = marching_cubes(real_map, 0.05) mp.plot(v, f)

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move models relative to each other
by Raik Grunberg 14 Feb '23

14 Feb '23

Dear ChimeraX developers and users, I would like to move to different proteins that I have opened separately into a particular position relative to each other. In the old Chimera, this is possible by going to the Model panel, then selecting one of the two models as "Active" and the other one not and then making the normal rotation and translation moves which will now only happen on the "active" model. However, this "Active" column is missing in the ChimeraX Model panel and I cannot find any alternative way of doing this. Any suggestions? Thanks a lot in advance Raik -- This message and its contents, including attachments are intended solely for the original recipient. If you are not the intended recipient or have received this message in error, please notify me immediately and delete this message from your computer system. Any unauthorized use or distribution is prohibited. Please consider the environment before printing this email.

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