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Re: [ccp4bb] quick question... |
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- Protein crystallographyMain steps:- Protein purification- Crystallisation Special:- Programs for crystallography- X-ray detectors Basic tutorials:- Chemistry- Protein - Peptide - Amino Acids Xtal community:- CCP4BB |
CCP4bb navigationCCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999Subject: Re: quick question... From: Roger Rowlett RRowlett {- at -} MAIL {- dot -} COLGATE {- dot -} EDU Date: 2007-05-11 Here are the quick directions to reading CCP4 maps into pymol and creating nice diagrams: 1. Use fft to create a map in CCP4. (This task can be run from the Run FFT-Create Map option undere Map & Mask Utilities) You can create a simple map or a nFo-mFc map as you wish. Select the option to cover 'all atoms in PDB file'. For pymol to read the map later, you will need to add the file extension .ccp4 to the generated map. You may find this map too coarse to make for a pretty diagram. You can generate a nicer (albeit much larger) map by re-running fft with a tighter grid spacing. I usually take the default values generated by FFT and double them. You can change grid spacing under 'Infrequently Used Options'. 2. Open pymol and read in your PDB file. Create a selection about whatever you want to see the map around. I usually display the selection as sticks. 3. Open your map in pymol, e.g. mymap.map.ccp4 (you need the ccp4 extension) 4. To display the map around your selection (e.g., named 'site') issue a command similar to this: isomesh map, mymap.map.ccp4, 2.0, site, carve=1.6 This command will create a mesh object map from mymap.map.ccp4, countoured at 2.0 sigma, around the selection 'site', only within 1.6A of selected atoms. You can change the contour level and carve parameter to suit. 5. For a publication quality figure than can be labeled in GIMP or Photoshop, I would further suggest: * select the map object and change the color to 30% gray * change the background to white with the command 'bg_color white' You should be able to generate a really nice diagram that look something like the attached image. The operation of CCP4 or pymol is platform-independent. Cheers, ___________________________________________ Roger S. Rowlett Professor Department of Chemistry Colgate University 13 Oak Drive Hamilton, NY 13346 tel: (315)-228-7245 ofc: (315)-228-7395 fax: (315)-228-7935 email: rrowlett@mail.colgate.edu -----Original Message----- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of James Pauff Sent: Friday, May 11, 2007 12:06 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] quick question... Good day all, First off, thank you all so much for your help a couple days ago! I just have a quick question regarding the use of CCP4 to generate density maps. Is there a way to generate a map(s) that can be read into PyMol? I understand that PyMol can only read CNS or XPLOR maps, is this correct? Is there a means by which I can output maps (on a Windows platform) in a format that can be read by PyMol? My only option in CCP4 is to create my FFT map in CCP4 format. Thank you, Jim ________________________________________________________________________ ____________Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow CCP4bb navigationCCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999 |
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