- Chimera-users - RBVI Mailing Lists

difficulty in using chimera for large PDB files
by Shruti Khare 05 Dec '16

05 Dec '16

Dear Sir/Madam, When we use chimera to visualize PDB files with ~18,000 atoms (PDB ID 5FUU) even rotating the molecule is slow in chimera. The computer has 6GB RAM. Would upgrading RAM help or we need to get a graphics card installed? Graphics card capacity should be 2GB or higher? Could you please tell me the minimum computer configuration required by chimera to handle large PDB files? Also what is chimera's maximum limit for handling PDB files given a computer with very good configuration? Thank you. -- Shruti Khare Graduate Student Prof. Raghavan Varadarajan Lab Molecular Biophysics Unit Indian Institute of Science Bangalore +91-80-2293-2612 -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.

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pipes and planks
by Kyle Morris 02 Dec '16

02 Dec '16

Dear Chimera dev, I am using the pipes representation. In this case is it still possible to color/highlight a segment by residue number? Using the normal commands when displaying pipes doesn’t update the color, only on the original model. Thanks for your help! Best wishes, Kyle

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Selected measure angles
by Soumya Govinda Remesh 01 Dec '16

01 Dec '16

Hello, I have just modified the loop script available here ( http://www.rbvi.ucsf.edu/chimera/docs/ProgrammersGuide/basicPrimer.html) to measure certain angles and distances. I just want to know if there is a way to export the individual values of angles and distances to a file other than parsing from the reply-log. Thank you. Best, Soumya Govinda Remesh, Ph.D. Postdoctoral Fellow at Advanced Light Source Lawrence Berkeley National Laboratory 1 Cyclotron Road MS 6R2100 Berkeley, CA 94720 (phone) 510-495-8179 (cell) 804-402-8730 sgremesh(a)lbl.gov

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saving pdb with transformed coordinates
by Michael Elbaum 01 Dec '16

01 Dec '16

Dear Chimera people, I'm trying to create a series of pdb files showing a single structure rotated around a given axis. Using the GUI I can turn the molecule and save the pdb after unclicking the "Use untransformed coordinates" box. However, when I run a script using the write command I don't know how to invoke this option. The docs on the "relative" option suggest that the default is to write transformed coordinates. I've tried the following: for i in xrange(0,90,10): rc("rock " + "y " + str(i) + " 1") fn = basefn + str(i) + '.pdb' rc("write format pdb 0 " + fn) and the files end up identical although the rotation around y does appear on the screen. I had the problem in version 1.10.2 and it remains after upgrading to 1.11. thanks for your help, Michael

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Unit cell
by Neha Gandhi 01 Dec '16

01 Dec '16

Hi Elaine, I have tried to look at the unit cell information of pdb Id :3HR2. It is a fiber diffraction structure of collagen with only CA coordinates. I tried using different programs like VMD to visualise unit cell, the unit cell is at the beginning of N terminus in agreement with experimental paper. Whereas in Chimera it is not the case. How can I visualize the unit cell of 3HR2 structure in Chimera and also number of molecules within one unit cell? Many thanks, Neha -- Regards, Dr. Neha S. Gandhi, Vice Chancellor's Research Fellow, Queensland University of Technology, 2 George Street, Brisbane, QLD 4000 Australia LinkedIn Research Gate

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Re: [Chimera-users] failing to open saved PDBs
by Healey, Joe 30 Nov '16

30 Nov '16

Hi Elaine, OK, that is what I had expected to happen yes - and that NMR ensemble looks to be what I was anticipating. I've attached the PDB chimera created here. I'm no expert on PDB internal formatting but it at least looks to me like there are coordinates, sequence information etc etc. I had thought that I had taken care to make sure whole models were saved (not just sel atoms), but I'll replicate it to make sure. Applying the preset in any event didn't work. Maybe you can spot what's wrong with it? Joe Healey M.Sc. B.Sc. (Hons) PhD Student MOAC CDT, Senate House University of Warwick Coventry CV47AL Mob: +44 (0) 7536 042620 | Email: J.R.J.Healey(a)warwick.ac.uk Jointly working in: Waterfield Lab<http://www2.warwick.ac.uk/fac/med/research/tsm/microinfect/staff/waterfield…> (WMS Microbiology and Infection Unit) and the Gibson Lab<http://www2.warwick.ac.uk/fac/sci/chemistry/research/gibson/gibsongroup/> (Warwick Chemistry) Twitter: @JRJHealey<https://twitter.com/JRJHealey> | Website: MOAC Page<http://www2.warwick.ac.uk/fac/sci/moac/people/students/2013/joseph_healey>

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more questions about visualizing the backbone.
by A G Szabo 30 Nov '16

30 Nov '16

Last week I asked a question regarding about how to visualize the backbone atoms. I have figured that out. I am working with a peptide that forms an amyloid structure. The peptide strands form a beta sheet. When I select two of the peptide units that are hydrogen bonded to form two strands in the beta sheet, the strands are shown as a coil type structure rather than a flat beta strand. How can I change the coil backbone to a beta strand structure? Second part is there a simple way to suppress the side chains but leaving the backbone atoms? I have included two peptide units that are hydrogen bonded to one another. Thanks Arthur G. Szabo

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Ca-Ca difference plot
by Luca Pellegrini 30 Nov '16

30 Nov '16

Hi, I have superimposed two structures of the same protein in two different conformations, and now I would like to calculate a plot of the distances between alpha carbons for each residue in the two conformations, to quantify the relative movement of different domains in the protein structure. Can anyone please explain a simple way of doing this in Chimera? Apologies if I missed something obvious, I tried 'RR distance maps' but couldn’t figure out how to do this simple task. Best regards, Luca Luca Pellegrini, PhD Department of Biochemistry University of Cambridge 80 Tennis Court Road Cambridge CB2 1GA UK Email: lp212(a)cam.ac.uk Phone: 0044-1223-760469

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Visualizing Orientation of Side Chains
by Christian Bock 30 Nov '16

30 Nov '16

Hello, I am new to Chimera and want to visualize how the side chain orientation for a specific residue changes in different structure predictions. Means I have a correct structure and several predictions and I want to see how different the orientations are among the predictions with reference to the correct structure. I was looking at the MD movie but I am not sure if it's smart to put the correct structure and all predictions into one .pdb file to make a movie. Does anyone has other suggestions? Thanks, Christian

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using Chimera to superimpose structures using sequence alignments
by Elaine Meng 28 Nov '16

28 Nov '16

Hi Deepak, You would still have to show the Chimera GUI (it cannot be done running Chimera with no GUI), but if you mean using a script instead of interactively choosing menu items, it may be possible. However, there is no Chimera command to do this. It would require a Python script. For future reference, we recommend sending Chimera questions to the chimera-users(a)cgl.ucsf.edu list (which I CC’d here, so you do not need to re-send this question). Since today is a holiday, and I do not know Python, somebody may be able to help you with this question next week. Best, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Nov 24, 2016, at 3:08 PM, Deepak Kumar <deepakk1(a)andrew.cmu.edu> wrote: > Dear Dr. Meng, > I am a Bioinformatician at the Computational Biology Department of Carnegie Mellon University. I have been using Chimera for visualization purposes and for many other of its features. I got to learn about your expertise from here: > > http://www.cgl.ucsf.edu/home/meng/index.html > > May I please request you to give your suggestions on this problem mentioned below: > > I know of one feature "multialign viewer" which uses a fasta alignment file to superimpose two pdb structures in Chimera. However, I have been using this feature through the GUI of Chimera. I am in need of using this feature standalone i.e superimpose two pdb structures based on a fasta alignment file. May I please request you to let me know, how can I perform this step standalone and not through Chimera GUI. > > Thank you so much for your time and consideration. > Yours Sincerely, > Deepak

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