- Chimera-users - RBVI Mailing Lists

Building protein-protein complex with known interacting residues
by fei.wu＠chem.utah.edu 03 Mar '14

03 Mar '14

Dear Chimera Team, I am studying the interactions between three enzymes with their biological assembly structures available in PDB. Using mass spectrometry, I have been able to identify interfacial residues, and what I want to do is build up a super complex (made of the three proteins) in a desired way that these proteins are oriented by interactions between experimentally-determined residues. Would you please tell me that, if I can make or draw this in chimera? And I am also trying to compare experimentally-proposed complex structure with simulated structure. Is there a specific way in chimera to simulate interactions between two or more proteins? I found that when I opened multiple protein files in one session, chimera would gave me a complex of these proteins (not always true with different pdb files). Is this an automatic generation of simulated protein complexes or just a superimposition of part of proteins? Thanks, Fei -- Fei Wu, Ph.D. candidate Shelley D. Minteer Group Chemistry Department University of Utah Phone: 385-234-0603 Email: fei.wu(a)chem.utah.edu

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Expanding EMdatabank map to full map
by Jason C Porta 03 Mar '14

03 Mar '14

Greetings, I am searching for a way to take a map from the EMdatabank which is just a cut-out of an icosahedral asymmetric and generate the full map via the sym operators. I see there are similar options for generating sym-related models, but is there a way to do this for a section of a map in Chimera? Many thanks, Jason P

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pocket cavity file produced by rdock
by Fabian Glaser 02 Mar '14

02 Mar '14

Hi all, I am trying to upload and examine the cavity file produced by the rbcavity program from rdock, an open source docking program. There are both a binary form and a regular file "RBT FFT GRID" but I am not able to upload or visualize them. Can you please help me to do it? Files are attached. Thanks a lot, Fabian

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Using sym command to generate icosahedral cage
by Yen-Ting Lai 25 Feb '14

25 Feb '14

Hi, I noticed that the sym command can be used to generate icosahedral symmetry, but it requires that the molecule to be oriented in specific ways (222, 2n5, n25, ...), which requires aligning the symmetry axes to the X, Y or Z axes. I am wondering if there is a way to specify the symmetries axes by vectors (instead of aligning them to the three principal axes) and then use sym command to generate the whole icosahedral cage? Yen

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Chimera hardware resources
by Derrick Smith 18 Feb '14

18 Feb '14

Hi Chimera users, I've been working with what are probably some pretty big files (400 MB - 3 GB) for ultramicrotomed sections of holograms. I've trimmed the volume down as well as I can while keeping it large enough to see what we ultimately were aiming for. However, I am running into some hardware resource issues. None of our computers in the lab can handle it, so I've been using my gaming rig at home to do it. I run a server off it also, so have some decent hardware to work with, but I cannot figure out how to reallocate the resources that Chimera seems to default to. I have 64 GB of system RAM available, and after recording 1-2 movies of rotations or a flythrough of clippings etc. Chimera has never used more than 1.5 GB. My graphics card has 4 GB. After filtering and post-processing, before any rotation or video capturing, the vid card has used around 2 GB already. During video capture, depending on if I'm rotating or clipping (clipping uses up a lot more faster), the vid card memory slowly gets eaten up, eventually crashing Chimera altogether. I can usually only get about 800-1000 frames before this happens on a smaller file (400 MB), and usually can't get through a whole 10s, or 250 framed, video on one of the larger files. I have pretty limited experience with this program, so I'm hoping it's a simple settings or otherwise fix I've overlooked. Any suggestions on this? Best, Derrick -- Derrick Smith Drexel University Soft Materials Group Philadelphia PA 19104 dms348(a)drexel.edu http://www.mse.drexel.edu/srg/

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Receptor-Ligand bonding at the LBP
by Graziella Portelli 13 Feb '14

13 Feb '14

To whom it may concern I would like to ask if there is a function where the bonds with which the ligand binds inside the LBP of the receptor would be visualised, or whether one has to search the amino acids involved in binding with the ligand one by one? I thank you in advance for your time Graziella Portelli

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Symmetry-aware segmentation?
by Joel Meyerson 13 Feb '14

13 Feb '14

Is it possible for Chimera to segment with an awareness of symmetry, such that the collection of segments in the asymmetric units are identical? For example, a molecule with C2 symmetry would have two copies of each segment. Also, is it possible to select a segment and then have Chimera further sub-divide that segment into additional segments? Thanks, Joel

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when will NoResidueRotamersError be raised?
by Xiao-Bo Li 13 Feb '14

13 Feb '14

I would like to mutate one residue to another. So far, the only way I found is to use the rotamers of the other residues on the original. I'm using chimera's python script. I would like to know if the NoResidueRotamersError will only be raised for residues that don't have rotamers like GLY. If not, then how can I replace the amino acid residue that I want to mutate? I am using the "getRotamers" function, which returns this error. XBL

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Problem in using BondRot
by amin＠imtech.res.in 13 Feb '14

13 Feb '14

Dear Chimera users, I am trying to write a script to change the phi and psi angle of a peptide. I am trying to adapt the code from http://plato.cgl.ucsf.edu/pipermail/chimera-users/2005-September/000456.html . I am trying to invert the angles so I am multiplying the angles by -1. My code is import chimera from chimera import selection, UserError, BondRot, replyobj opened = chimera.openModels.open('fun.pdb') mol = opened[0] RES_LIST = mol.residues for res in mol.residues: b = str(res.phi) if b != 'None': c = -1*float(b) atomsMap = res.atomsMap N = atomsMap['N'][0] CA = atomsMap['CA'][0] C = atomsMap['C'][0] CAmap = CA.bondsMap phiBond = CAmap[N] psiBond = CAmap[C] phiAnchor = N psiAnchor = CA phi = BondRot(phiBond) phi.setAngle(c, phiAnchor) When I run this script i get the error phi.setAngle(c, phiAnchor) AttributeError: '_molecule.BondRot' object has no attribute 'setAngle' Can someone please help me with this? Warm regards. Amin.

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un-subscribe
by Ted Holman 12 Feb '14

12 Feb '14

hi there i made a mistake and signed up for the email questions on chimera to be copied to me. i tried to un-subscribe but it did not work. can you tell me how to do this? thanks ted ___ Ted Holman, Ph.D. Professor Chemistry and Biochemistry Department 250 PSB, Thimann Receiving University of California, Santa Cruz Santa Cruz, CA 95064 Phone: 831-459-5884 Email: holman(a)ucsc.edu

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