March 2010 - Chimera-users - RBVI Mailing Lists

groups
by Jean-Paul Armache 03 Mar '10

03 Mar '10

Hello, I am often juggling between different sets that are to be turned on/off together. Is there a way of grouping maps/pdbs so that instead of turning 20 pdbs on, i could just click on a group to which they belong ? If there is something like that, could you point me to it ? And if not, would it be possible to have it in the Model Panel? Best regards, Jean-Paul Armache

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chimera-users@cgl.ucsf.edu
by Jozef Lewandowski 03 Mar '10

03 Mar '10

Hi everybody, I am trying to get a list of all hydrogen atoms within certain distance from a specific atom. I found an old thread suggesting using findclash for that. When I use: findclash #0.265:4@c overlap -8 hbond 0 ignoreIntraRes false log true bondSeparation 0 everything works fine and I get the list of all the atoms within the desired distance limits. However, I get all types of atoms. To select only for contacts to hydrogens, I have tried to add the "test" option but when I type: findclash #0.265:4@c overlap -8 hbond 0 ignoreIntraRes false log true bondSeparation 0 test @H the procedure does not report on any contacts. Am I misunderstanding the syntax? What is the way to get only the distances between :4@c and all hydrogens within ~10A? Moreover, I am ultimately interested in the sum of all reported distances (or more specifically sum of (1/r)6 where r is the distance). Is there simple way to get this value calculated in Chimera (e.g. simple script)? Unfortunately, I have no idea about Python coding, so right now I have to import the list to Excel and calculate what I need in there (which is fine for a few atoms but slightly tedious when you have to check several hundred of them...). Any help would be appreciated. Thanks, Józef

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Sum of distances
by Jozef Lewandowski 03 Mar '10

03 Mar '10

Hi everybody, I am trying to get a list of all hydrogen atoms within certain distance from a specific atom. I found an old thread suggesting using findclash for that. When I use: findclash #0.265:4@c overlap -8 hbond 0 ignoreIntraRes false log true bondSeparation 0 everything works fine and I get the list of all the atoms within the desired distance limits. However, I get all types of atoms. To select only for contacts to hydrogens, I have tried to add the "test" option but when I type: findclash #0.265:4@c overlap -8 hbond 0 ignoreIntraRes false log true bondSeparation 0 test @H the procedure does not report on any contacts. Am I misunderstanding the syntax? What is the way to get only the distances between :4@c and all hydrogens within ~10A? Moreover, I am ultimately interested in the sum of all reported distances (or more specifically sum of (1/r)^6 where r is the distance). Is there simple way to get this value calculated in Chimera (e.g. simple script)? Unfortunately, I have no idea about Python coding, so right now I have to import the list to Excel and calculate what I need in there (which is fine for a few atoms but slightly tedious when you have to check several hundred of them...). Any help would be appreciated. Thanks, Józef

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constraints and restraints
by Elaine Meng 02 Mar '10

02 Mar '10

Hello, The Chimera release notes describe what is new or changed in a release: <http://www.cgl.ucsf.edu/chimera/docs/relnotes.html> ... clicking the "1.4" link: <http://www.cgl.ucsf.edu/chimera/docs/relnotes/1.4.html> The meaning of "constraint" "restraint" and "tether" may change based on which program you are using. Each program should explain it in its own documentation. In programs I've used, "constraints" meant atoms are completely fixed in place (frozen, cannot move) whereas "restraints" use a force constant like a spring, and allowed some movement. I don't have any opinion on the technical definition of "tethering." Again, don't rely on my descriptions as final because different programs may use the words to mean different things. Chimera minimization only allows "fixing" some of the atoms so they can't move at all. It does not allow holding atoms in place with force constants. http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/minimize/minimize.… > I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html > nice to give you a letter! > is there a new one ,really? > what is the new feature in the least software? > > I want constraint ,restraint and tether some atoms and backbone. > how can I do constraiting ,restrainting and tethering in > software.how can i set value for constraiting ,restrainting and > tethering. > what is the difference between them? > > thank you! > >

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NAMD trajectory and AMBER topology
by Francesco Musiani 02 Mar '10

02 Mar '10

Hi all, I would like to visualize in Chimera a trajectory obtained with the program NAMD, but I have a .prmtop topology file generated using AMBER instead of a .psf topology file. I have these files beacuse in NAMD is possible to use AMBER format topology. Is it possible to implement an additional feature in Chimera which allows to visualize NAMD trajectory using AMBER topology? Thanks in advance, Francesco -- Francesco Musiani -- Laboratory of Bioinorganic Chemistry Department of Agro-Environmental Science and Technology University of Bologna Viale Giuseppe Fanin 40, I-40127 Bologna, Italy Phone: +39-051-2096236 - Fax: +39-051-2096203 E-mail: francesco.musiani(a)unibo.it Web: http://bioinorg.agrsci.unibo.it

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load pdb files from local PDB mirror
by Mark Moll 02 Mar '10

02 Mar '10

I have a local mirror of all PDB structures (as pdb files). It’d be nice if Chimera could use this, but it seems that Chimera expects a “flat” directory structure rather than the hierarchical directory structure of the PDB. For example, on my machine the pdb file for 1ady is stored in ${HOME}/pdb/ad/pdb1ady.ent.gz, but when I fetch by ID, the file will not be found. Instead, Chimera will download the file and save it in ${HOME}/pdb/PDB/1ADY.pdb. Is there some way to handle both cases (flat & hierarchical directory structure)? -- Mark

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multi-threading
by Jean-Paul Armache 02 Mar '10

02 Mar '10

Hello, I know that this topic might've emerged earlier, but I was curious whether there were any plans to implement multi-threading into Chimera ? Best regards, Jean-Paul Armache

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Re: [Chimera-users] How are chains paired in morphing?
by Eric Pettersen 01 Mar '10

01 Mar '10

The sequences are in input order unless you ask for the return value to be a dictionary (with the 'asDict' keyword). --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu On Feb 22, 2010, at 11:25 AM, Conrad Huang wrote: > There's a comment in Segment.py: > > # Get the chains from each model. If they do not have the > # same number of chains, we give up. Otherwise, we assume > # that the chains should be matched in the same order > > It uses molecule.sequences() to get the chains. Eric, does > sequences() return the chains in input order, or is it random (eg > hash order)? > > Conrad > > On 2/22/2010 10:26 AM, Thomas Goddard wrote: >> Bobby Laird showed me a homo-tetramer with chains A, B, C, D that >> when >> morphed between two states with the Chimera morph conformations tool >> swapped two of the monomers. In other words the 4 chains from one >> state >> weren't correctly paired with the 4 chains from the other state so >> two >> monomers exchanged positions during the morph. The tetramers were >> built >> from dimers 1pfk and 2pfk by using the symmetry of the unit cell with >> other software (coot?). >> >> How does morph conformations decide which chains to pair? >> >> >> Tom >> >> _______________________________________________ >> Chimera-users mailing list >> Chimera-users(a)cgl.ucsf.edu >> http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users >

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Chimera-users March 2010