December 2007 - Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] Chimera-users Digest, Vol 56, Issue 14
by Jonathan Hilmer 17 Dec '07

17 Dec '07

Ryan, Try this as a way to figure out what you can do with an object: dir(chimera.selection.currentResidues()[0]) In the above command I've indexed the list of selections to return just one object, and the dir() function will return a list of names defined by the currentResidues module. It should contain something like the following: ... 'addAtom', 'atomNames', 'atoms', 'atomsMap', 'bondedTo', 'count', 'findAtom', 'findRangeAtoms', 'getDefaultRibbonStyle', 'hasRibbon', 'id', 'isHelix', 'isHet', 'isSheet', 'isStrand', 'isTurn', 'kdHydrophobicity', 'label', 'labelColor', 'labelOffset', 'molecule', 'numAtoms', 'oslChildren', 'oslIdent', 'oslLevel', 'oslParents', 'oslTestAbbr', 'removeAtom', 'ribbonBinormals', 'ribbonCenters', 'ribbonColor', 'ribbonData', 'ribbonDisplay', 'ribbonDrawMode', 'ribbonFindStyle', 'ribbonFindStyleType', 'ribbonFindXSection', 'ribbonNormals', 'ribbonResidueClass', 'ribbonStyle', 'ribbonXSection', 'selLevel', 'type' If you try: chimera.selection.currentResidues()[0].type it will return a string with the 3-letter aa code, and the other options displayed by dir() will output useful things such as more strings, lists, or other objects that can be likewise explored. Try this combination: mySel = chimera.selection.currentResidues()[0] print "%s, %s" % (mySel.oslIdent(), mySel.type) On my test structure it returns '#0:127.A, ARG'. The second line is equivalent to 'print str(mySel.oslIdent() + ", " + mySel.type)', but the formatting I used in the above example helps to keep things clean if you have a complicated output that needs to have a specific format. There are some more advanced features of that approach detailed here: http://www.python.org/doc/1.5/tut/node45.html Jonathan > Date: Fri, 14 Dec 2007 19:55:39 -0500 > From: Ryan <pavlovicz.7(a)osu.edu> > Subject: Re: [Chimera-users] printing "zone" search > To: chimera-users(a)cgl.ucsf.edu > Message-ID: <17bf4817f850.17f85017bf48(a)osu.edu> > Content-Type: text/plain; charset=us-ascii > > Hi Eric, thanks for your help. I'm getting closer to achieving the results i'd like. > > So i've been able to properly select the residues within a specified radius of my ligand, but am a little confused as to how Chimera handles the selection list. If i try: > > print chimera.selection.currentResidues() > > i get a list like this: > > > [<_chimera.Residue object at 0x578d2020>, <_chimera.Residue object at 0x578cbfb0>, ... ] > > but if i try: > > for x in chimera.selection.currentResidues(): > print x > > i get output that is much closer to what i'm looking for: > > > #0:499 > > #0:496 > > ... > > What is the reason for the difference between these two forms of output that seem to be accessing the same list? Also, is there a way i can get more detailed output with residue names and numbers, such as ['#0:TYR499','#0:TRP496',...]? > > Sorry if these questions are answered elsewhere, but i could not find the answers online. Is there a document out there that can teach me how to better master the Chimera Python modules for scripting? I'm no Python expert -- i've so far only been learning things as i need them. Thanks again, > > ryan

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Re: [Chimera-users] other/5067 (error adding hydrogens)
by Eric Pettersen 17 Dec '07

17 Dec '07

Hi Jean-Francois, I have seen this error reported, but only very rarely (maybe once a year at most). Is there any chance you can tell me how to reproduce it? --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu

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setting pdb path for local mirror
by Moo Cow 17 Dec '07

17 Dec '07

Sorry for an easy question. Chimera has a hook to use a local mirror of the PDB (preferences-PDB) I am too thick to see what path to give it. If you have the PDB, you have the top level /blah/blah/pdb the structure directory /blah/blah/pdb/data/structures/all and the divided directory /blah/blah/pdb/data/structures/divided/pdb When a non-python reader looks at the code (__init__.py), it seems to be trying out the divided directory IDcode = IDcode.lower() subpath = IDcode[1:3] + os.sep + "pdb" + IDcode + ".ent" pdbDir = systemPDBdir() if pdbDir is not None: ..... but this does not look correct. The PDB divided path would want subpath IDcode[1:2] to get the subdirectory "pt" from a file like "5pti" Many thanks and sorry for a seemingly daft question. -- Got No Time? Shop Online for Great Gift Ideas! http://mail.shopping.com/?linkin_id=8033174

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Loading .dx maps to chimera
by maya shcushan 17 Dec '07

17 Dec '07

Dear sir, I am trying to load a .dx file (electrostatic potential) onto a molecule in chimera. I successfully loaded the map onto a the molecule's surface. The problem is the potentials I get look differently than the original map. That is, the potentials appear different in the visualization tool of PMV, the program which generated the .dx file I tried to e-load on chimera. Thanks, Maya Schushan, Tel-Aviv university, Israel.

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crystallographic symmops and lattice translations in Chimera
by Boaz Shaanan 16 Dec '07

16 Dec '07

Hi, Since the question was raised before, I think I know the answer to my first question about lattice translations but let me verify: 1) Chimera can apply crystallographic symmetry operations to the model as they're listed in the pdb file but it won't apply lattice translations, or in other words, won't display molecules in neighbouring unit cells. Am I correct ? maybe you can surprize me me on this and prove me wrong ? 2) Is it possible to draw the unit cell boundaries after reading in the pdb or should I read in a dummy pdb with coordinates of the unit cell vertices ? Cheers, Boaz Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Phone: 972-8-647-2220 ; Fax: 646-1710 Skype: boaz.shaanan‎

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Re: [Chimera-users] printing "zone" search
by Ryan 14 Dec '07

14 Dec '07

Hi Eric, thanks for your help. I'm getting closer to achieving the results i'd like. So i've been able to properly select the residues within a specified radius of my ligand, but am a little confused as to how Chimera handles the selection list. If i try: print chimera.selection.currentResidues() i get a list like this: > [<_chimera.Residue object at 0x578d2020>, <_chimera.Residue object at 0x578cbfb0>, ... ] but if i try: for x in chimera.selection.currentResidues(): print x i get output that is much closer to what i'm looking for: > #0:499 > #0:496 > ... What is the reason for the difference between these two forms of output that seem to be accessing the same list? Also, is there a way i can get more detailed output with residue names and numbers, such as ['#0:TYR499','#0:TRP496',...]? Sorry if these questions are answered elsewhere, but i could not find the answers online. Is there a document out there that can teach me how to better master the Chimera Python modules for scripting? I'm no Python expert -- i've so far only been learning things as i need them. Thanks again, ryan

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Multi-scale models and BIOMT
by Ken Jang 14 Dec '07

14 Dec '07

Hello, I work at Boston University working mostly with pili and helical reconstructions. Recently we have been trying to fit our subunit structures into maps generated from EM data. Because what we work with are helical in nature, we use BIOMT symmetry since it is the easiest to generate using readily available data. We wanted to see just how close our subunits get and wanted to use the MSC or Color Zone commands, but we have run into a problem with the Multi-Scale Models command. Since we are using the same BIOMT data, we assumed that Multi-Scale Models would use the same origin and orientation. This appears to be the case if we don't move the subunit structure after opening it, but after we move the subunit, the generated models don't seem to be in any relavent orientation. I have attached two pictures, both from the same view, and one showing the placement of the subunits using the 'sym' command and the other showing the surface models using Multi-Scale models. Both cases were generated off the same selected subunit. Any advice or clarification on how to use Mult-Scale Models and BIOMT information would be greatly appreciated. Be seeing you- Ken Jang -and all places are alike to me

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Re: [Chimera-users] printing "zone" search
by Ryan 14 Dec '07

14 Dec '07

I am actually currently interested in doing something similar to Francesco's previous question about writing out a list of residue names within a certain zone of a ligand -- however i would like to do this from a Python script. I tried to find the zone selection command to use in a script, but could not. Would it be easiest to just use the runCommand('z<') function to select a zone? Also, when the zone is selected, are the selected residue names stored in a list? If so, how can i access this list to print out the residue names into an output file of my own? Thanks a lot, ryan

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edges
by Vincent Racaniello 14 Dec '07

14 Dec '07

When I display a protein as an edged ribbon, sometimes they have a black line on the edges, other times none. There seems to be no consistency in this behavior. The same also happens with surfaces. Is there a way to regulate this appearance?

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Morphing on small ligand
by Jean Didier Pie Marechal 13 Dec '07

13 Dec '07

Hi everyone, I have a " small" ligand with two substantially different conformations. Just for interest: could we use the morphing module to generate intermediate conformations between those two structures? Cheers, JD Dr. Jean-Didier Maréchal Professor Lector Unitat de Química Física Departament de Química Universitat Autònoma de Barcelona Edifici C.n. 08193 Cerdanyola (Barcelona) Tel: +34.935814936 e-mail: JeanDidier.Marechal(a)uab.es

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Chimera-users December 2007