- Chimera-users - RBVI Mailing Lists

Question Regarding on Finding Distances
by Xiong, Padua L 05 Jun '18

05 Jun '18

Hi there, My name is Padua and I'm an undergraduate research assistant working on pharmacogenomics. To do this, I have been using your program UCSF Chimera. I've been trying to find the distances between a protein and a drug but keep running into problems with selecting an atom in the graphics. When I try doing Ctrl-click or Shift-Ctrl-click to select an atom, I don't select anything at all (nothing is highlighted green as its supposed to when something is selected). My professor I'm working under has tried changing the mouse settings as well. Is there something I'm missing that's not listed in the User's Guide and tutorials? Much thanks, Padua

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Atom Specification not working in exported PDB
by Gustaf Olsson 03 Jun '18

03 Jun '18

Hello again Chimera Users So now that I have the “movie” command working decently, it turns out that I cannot export a PDB file from my MD simulation and retain the ability to select by residue or atom number. PDB files generated by other software (PACKMOL, AMBER) works fine though when I exported a PDB file from a fram in an AMBER MD simulation using chimera, I can open the file, I can select using residue names though trying to refer to atom or molecule numbers does not work. To be clear, the exported PDB file contains multiple molecules and solvent, all ar present and the file loads though trying to run commands like show :17 ~show @536-593 Affects EVERY atom and molecule in the system when it should only affect residue 17 (by specifying residue number OR all atoms in that residue). Using the show :XXX works as intended though this affects all residues XXX and I only want to affect residue 17. Am I doing something wrong or can I solve this in a simple way? Best regards // Gustaf

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Place marker at centre of volume box python command
by Kyle Morris 01 Jun '18

01 Jun '18

Hi Chimera dev, Is there a python command to place a marker at the precise centre of a volume’s box, regardless of the centre of mass of the volume in the box? I have played with creating dummy volumes and measuring their centres but it’s clunky and got a bit stuck with doing this. A single command would be cleaner, if it’s possible. As always thanks for your help! Best wishes, Kyle

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Command line syntax questions
by Divita Mathur, Contractor Code 6910, FN 01 Jun '18

01 Jun '18

Hi I am trying to write an alias and am curious if I can do the following using command line (in order to include them in the alias): 1. Separate chains that belong to the same model – can I change the model # on a single chain from an existing model? For example, I built a DNA duplex, selected one chain (sel :.A) and tried to change the model # (combine sel model 8 close true) but the new model also includes chain B. 2. Change residue number of a residue in a chain. I combined a small molecule to a DNA chain between residues 18 and 19, but after combining, the molecule’s residue number remains 1. I would like to change it to 19 or 18. 3. Following point #2, I also want to assign the new molecule the same chain ID – A. In the pdb file, the chain ID is blank for the newly inserted molecule. Thank you for your help. I also want to mention that the Chimera user discussion portal has been very helpful otherwise! Best, -- Divita Mathur Postdoctoral Research Fellow Center for Bio/Molecular Science and Engineering Naval Research Laboratory Washington DC 20375 (202) 767-0687 (Office) divita.mathur.ctr.in(a)nrl.navy.mil

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Recording a movie of an MD simulation
by Gustaf Olsson 30 May '18

30 May '18

Hello everyone First time posting, looking for some advice. I have an MD simulation that was produced with the AMBER software package and I want to record a movie (MP4) file of the simulation. I wanted to use a CMD file and not go through the GUI since this would be a step in a series of steps and I was also hoping to perform some “in movie” modifications to the structure though I quickly ran into a huge issue, the frame rate. So basically i tried something like this: movie record size 3840,2160 format png supersample 3 coordset #0 1,-1 wait 10 movie stop movie encode output /Users/guolaa/Desktop/Arbete/Konferenser/MIP2018/Presentation/myMovieFolder/mdSimulationBox.mp4 format mp4 quality highest >From this I received what looked like a single frame of “movie”. This seemed very strange to me since I assumed that this would be 500 PNG images resulting in a 20 second movie at 25 fps. It seems I’m missing something in the process since MD iterations, frames and frame-rates does not seem to match up. I’ve gone through the documentation regarding maxFramerate, movie, coordset and so forth and I can’t work out a decent strategy. I have 500 iterations (MD-frames) loaded, I want to record a smooth 10 seconds (-ish) long MP4 movie file covering the entire range of MD-iterations (first frame to last frame though not necessarily every frame in between) and I want to do this in a CMD script and not using the GUI menu system since I plan to do more things while recording at some point (manipulating representations). Thank you in advance for any input, best regards // Gustaf

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chimera clear selection
by Brian Ondek 29 May '18

29 May '18

Hi chimera help,I have been using chimera and find it extremely useful. I was finding particular protein sequences within my structures and hit clear selection under the select tab.Now whenever I try and find a seq, it wdoes not show up and "selection cleared" appears in the bottom right corner of the window. I tried to reboot and the issue persists.Interestingly I can still see amino acid and chain selections just fine.How can I undo this "clear selection" issue I inadvertently caused? Thank you in advance for your help.Brian Ondek

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Interface residues in domain-domain contacts
by IDIGO Nwamaka 29 May '18

29 May '18

Hi, I am quite new to chimera. I was wondering how I can locate interface residues in different domains within the same protein model. For example, my protein has 3 domains and I want to find out the interface residues for the different domains. Thanks! Amaka Idigo PhD Student www.ed.ac.uk/centre-genomic-medicine<http://www.ed.ac.uk/centre-genomic-medicine> Centre for Genomic & Experimental Medicine<http://www.ed.ac.uk/centre-genomic-medicine> www.ed.ac.uk University of Edinburgh Centre for Genomic & Experimental Medicine The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

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Surface mesh and coloring queries
by Bala subramanian 29 May '18

29 May '18

Dear Chimera friends, Good day. Please enlighten on the following queries, a) I would like to know if I can write the surface mesh calculated within chimera to a file. From the documentation of the surface command, it seems that it is not possible. My idea is to have the vertices and faces as outputs to be fed to a plotting tool aimed for webpage display. Please guide me if this is possible or the related source code I can modify to have the output. b) How does chimera color surfaces, for instance, coulombic surface. What I am not understanding is the way the surface colors are interpolated to atomic charges. I would like to adopt the method for my plotting purpose. Thanks in advance, Bala -- C. Balasubramanian

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display vectors
by Michał Kadlof 24 May '18

24 May '18

Hi, I'm running MD simulation and I would like to display forces vectors "live". My strategy is to run: MD Movie -> PerFrame Script -> In this script create a shape (cone), and update it every frame. I transformed my vectors into ration axis and angle, and run it. However it works extreamly slow, and even lowering quality of cone didn't help. Do you have any clues? Here is how my script looks like: #1: close #1; shape cone radius 0.2 height 3.051701874476991 center :47 divisions 10 color red rotation 1.003198923120698,-0.8433298543660601,-0.5373867542336597,180 #2: close #1; shape cone radius 0.2 height 3.054021942152826 center :47 divisions 10 color red rotation 1.0022878678774028,-0.8433406134841704,-0.5373745205242975,180 #3 ... -- pozdrawiam serdecznie Michał Kadlof <m.kadlof(a)cent.uw.edu.pl>

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coot/chimera model-map misalignment
by Gabriel Brandt 23 May '18

23 May '18

Hi. I've always been able to work around this problem, but I do often have to work around it, so I was wondering whether there's an easier way. Let's say I open a PDB file in Coot and export the map that it generates from the mtz file. If I attempt to open this ccp4-formatted map in Chimera, the coordinates appear to transformed so that the model and map are wildly misaligned in space. Normally, I work around this problem by using the map-generating feature in Phenix, which generates a model and map that align in Chimera. However, in this case, I'm trying to compare the maps that Coot generates on the fly to the those produced by Phenix, so it would be nice to be able to export a map from Coot and open it in Chimera. Thanks very much. gsb ………………………………... Gabriel Brandt Assistant Professor Department of Chemistry Franklin & Marshall College PO Box 3003 Lancaster, PA 17604 ph: 717.358.4846 shipping address: 415 Harrisburg Ave Lancaster, PA 17603 ………………………………...

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