July 2016 - Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] [chimera-dev] B factor
by Elaine Meng 28 Jul '16

28 Jul '16

On Jul 26, 2016, at 5:12 PM, Bashayer Althufairi <althufairib(a)mymail.vcu.edu> wrote: > Hello > As you know many crystallographers need to determine the ave. B factor of selected amino acids or sometimes they wanna know B factor of N-termius Vs. C-terminus of a protein. I'm working on a protein where I need to predict B factor of certain amino acids sequence as well as difference between the values for analysis. Is this possible by Chimera? If yes, I'd like to know Please the way step be step, If no, I wish you could recommend a simple way to do it by educational simple software like PyMol. > Thank You in Advance > -- > Bashayer Althufairi > Medicinal Chemistry department > Virginia Commonwealth University Hello Bashayer Althufairi, This is really a Chimera user question so I’m CCing the chimera-users mailing list. The chimera-dev list is for Chimera programming questions. Chimera doesn’t predict any B-factors, but you can see the B-factors from the PDB file for a structure, e.g. in a histogram in the Render by Attribute (in menu under Tools… Structure Analysis). This tool can color the structure to show the B-factor values. It also automatically calculates the average B-factor per residue (over the atoms in each individual residue so that each residue can have one number). It can also save the values to a file (see File menu of that tool) although of course the PDB file already contains the per-atom B-factor values. <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/render/render.htm…> See also the tutorial for coloring by B-factor: <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/tutorials/bfactor.html> But maybe you mean that you want to select several residues and then calculate a single average B-factor for them. You can do that with Attribute Calculator (in menu under Tools… Structure Analysis) <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/calculator/calcul…> For example, you could select several residues and open Attribute Calculator, turn on the options to “Restrict formula domain to current selection” and “Show calculation results in Reply Log”, calculate a new attribute named whatever you want for “molecules” with formula: average(atom.bfactor). Click Apply to calculate a single average over all selected atoms, value reported in Reply Log. If you have predicted B-factor values you can also read them into Chimera as a custom attribute (see file format for doing that <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/defineattrib/defi…> … it is the same format as used for the saving mentioned above). When you read in those values they are also available for use in Render by Attribute and in Attribute Calculator, and with the latter you could calculate the differences between the bfactor attribute from the PDB file and your custom attribute (the predicted values). The differences would then be another attribute also available for coloring using Render by Attribute. See also the attributes tutorial for examples of using Attribute Calculator and Render by Attribute: <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/tutorials/attributes.html> I don’t use other programs so I don’t have any advice about using them for this purpose. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco

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Help with Autodock Vina
by Jonathan Y Wang 28 Jul '16

28 Jul '16

To whom it may concern, Hi, I was trying to dock a ligand into my receptor and all of the other ligands so far have worked and outputted a value, but this one compound never outputs a .pdbqt file. The other files such as the .conf and .pdb files have been created, the bottom of the screen no longer says "execution in progress", and the green box remains. I've looked at the tutorial for AutodockVina online and tried fidgeting around with it, but I seem to be extremely lost. I was wondering if you had any pointers, tips, or anything at all that could help me. All the best, Jonathan Wang

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Auto start and nogui option causing segmentation fault?
by Daniel P Farrell 26 Jul '16

26 Jul '16

Hello, I don't know if maybe i'm doing something wrong, or if there's a problem, but I'm on a mac el capitan 10.11.6 and I'm getting these weird errors when I try to start chimera in nogui mode. I usually set various tools to auto-start once I start chimera, but recently I was messing around and added a few, and now I'm getting these errors when i start chimera via --nogui. Problem is, I don't know which one is causing the seg fault, but I feel like it shouldn't be calling these gui options with the nogui options on anyway. Once I started getting these errors I went to Favorites->add to favorites/toolbar->reset & save, and now I don't get the segfault. I do get a few other errors if I adda few back to the auto start / on toolbar options. chimera production version 1.11 (build 41179) 2016-07-15 05:43:21 UTC with many auto-start options on """ >chimera --nogui Exception in Tkinter callback Traceback (most recent call last): File "/Users/danpf/Desktop/Chimera.app/Contents/Resources/lib/python2.7/lib-tk/Tkinter.py", line 1538, in __call__ return self.func(*args) File "/Users/danpf/Desktop/Chimera.app/Contents/Resources/lib/python2.7/lib-tk/Tkinter.py", line 589, in callit func(*args) File "/Users/danpf/Desktop/Chimera.app/Contents/Resources/share/chimera/baseDialog.py", line 280, in _initialPositionCheck if not preferences.get(GENERAL, DIALOG_PLACEMENT): File "/Users/danpf/Desktop/Chimera.app/Contents/Resources/share/chimera/preferences/base.py", line 607, in get return self._category[category].get(name, KeyError: 'General' [1] 1045 segmentation fault ~/Desktop/Chimera.app/Contents/MacOS/chimera --nogui """ after removing most auto-start options """ >chimera --nogui Exception in Tkinter callback Traceback (most recent call last): File "/Applications/Chimera.app/Contents/Resources/lib/python2.7/lib-tk/Tkinter.py", line 1538, in __call__ return self.func(*args) File "/Applications/Chimera.app/Contents/Resources/lib/python2.7/lib-tk/Tkinter.py", line 589, in callit func(*args) File "/Applications/Chimera.app/Contents/Resources/share/chimera/baseDialog.py", line 280, in _initialPositionCheck if not preferences.get(GENERAL, DIALOG_PLACEMENT): File "/Applications/Chimera.app/Contents/Resources/share/chimera/preferences/base.py", line 607, in get return self._category[category].get(name, KeyError: 'General' Starting extension 'Model Panel' failed Starting extension 'Keyboard Shortcuts' failed Starting extension 'IDLE' failed > """ should I be adding a different flag or something when I start chimera via nogui? Thanks, Dan

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Saving Attribute settings and Worm Radius Consistency
by Nicole Persky 26 Jul '16

26 Jul '16

Hi All, I've started using Chimera to map two different datasets onto structures. For one, we use color, and for the other we use worm radius. I've encountered two problems while trying to make figures for publications: 1- when I save my session the image is saved but when I go to "render by attribute" to tweak the settings a little, the threshholds under colors and worm radius have been reset. How to I get them not to reset, but to keep the thresholds? 2- I am trying to compare three different images with the same worm radius thresholds. For one of the images the lowest number of my attribute is LARGER than the lowest number I want to define on my threshhold (I would like to set the lower worm radius to 1 for a value of 1 however for this dataset my lowest value is 2. I cannot just set the value starting at 2 because there is a gradient to the largest value that gets thrown off). Yet, I cannot set the threshold lower than the lowest value of my attribute. Does anyone know a way around this? thanks so much, Sincerely, Nicky

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saving multiple models in Chimera
by Kamil Kuder 26 Jul '16

26 Jul '16

Dear Sirs/Madamme I have multiple PDB'a (ca.40) in the model panel. While trying to save each model in single file using option "Save multiple models in multiple files" I got this message: You must provide a file name that contains either $name or $number. I set the name to eg. A1_01 and/or A1_$01 but none of this works. How shall I manage that? Many thanks Kind regards Kamil J. Kuder, PhD Jagiellonian University Medical College Faculty of Pharmacy Department of Technology and Biotechnology of Drugs Medyczna 9 30-600 Krakow POLAND tel.: +48 12 602 55 86

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Solvate Tool Trouble
by Mike Bergman 25 Jul '16

25 Jul '16

Hey there. I am having trouble with the solvate tool. I am using a dimeric model (PDB ID: 2Q1E) that isn't attached. Every time I try to solvate (model TIP3PBOX), it squishes the dimer together. I tried different angstrom box sizes - 3, 5, 10, 20. Running the simulation with them overlaid wouldn't give me any useful data as I'm looking for the changes in the dimer interface. Is there a way I can stop it from doing this? Should I use a different solvate method like Shell? Thanks. Sincerely, Mikey Bergman

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Threshold change
by Anindito Sen 25 Jul '16

25 Jul '16

Dear All, What will be the command (to be put in a script) for the change in the threshold of one of the displayed volumes without disturbing the others. Thanks Andy Dr. Anindito Sen (Ph.D)

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Linking four proteins
by Aditya Padhi 22 Jul '16

22 Jul '16

Dear Chimera users, I have predicted a protein structure having 4 different domains (for e.g. 1-94, 95-247, 248-444 and 445-509 residues) and all are part of a single protein from 1-509 residues. They have been predicted from different web-servers. Now, I want to join them together to form a single PDB file i.e. make a single PDB file containing the entire protein from 1-509 residues from the above 4 PDB files. Afterwards, I want to run a simulation of the built structure. I searched in google for possible solution but not sure which method would be better. Is there any solution to build this one structure in Chimera? Please let me know. Thank you so much. Aditya

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Color by hydrophobicity - select default scale?
by Oliver Clarke 21 Jul '16

21 Jul '16

Hi, As explained here ( https://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/hydrophob.html), Chimera currentlyuses the Kyte-Doolittle scale by default for coloring proteins by hydrophobicity. I wonder whether it might be worth updating this to use e.g. the scale described by Karen Fleming and co here ( http://www.pnas.org/content/108/25/10174.full)? This scale (and indeed most more recent scales in the literature, see review here: http://www.sciencedirect.com/science/article/pii/S0968000411001320) differ quite dramatically from the Kyte-Doolittle scale, which places trp and tyr as comparable to serine, which does not seem reasonable based on analysis of membrane protein structure. The Moon et al scale has the advantage that it is derived from studies of the energetics of protein folding and membrane insertion, as opposed to the energetics of isolated amino acid partitioning between ethanol and water, which as I understand it is what the K-D scale is mostly based on. Alternatively, would it be possible to allow users to select the default scale which it used for this purpose (I know it is possible to define a custom attribute for this, but this is a little cumbersome for something which sees frequent use). Cheers, Oli

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Positioning changing over time
by Marvin Albert 21 Jul '16

21 Jul '16

Dear chimera users, I was wondering whether any of you could help me with this simple problem: The aim is to make a movie displaying the evolution of predefined meshes over time (see attached python script). Overall the script works and produces a movie. However the mesh gets displaced slightly between the different time points. This results in an annoying random wiggling. I checked the original .wrl files and the indicated coordinates do have consistent positions (meaning the displacements are produced by chimera). How can I get a smooth movie? Might there be something unexpected happening when I repeatedly call runCommand(“open <file1.wrl>”) and runCommand(“close all”)? Thank you so much in advance! With kind regards, Marvin

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Chimera-users July 2016