Hi, How about this:
1. Expand solution A to fill an unit cell 2. Expand solution B to fill 3 x 3 x 3 = 27 unit cells 3. Superpose 1 to 2 en bloc Now we have a common origin, because components of the origin shift vector is within -1 to 1. 4. Delete everything outside the ASU 5. Match chains if necessary Best regards, Takanori Nakane On 2014-09-11 12:56, Seijo, Jose A. Cuesta wrote:
Correction: that won’t fix any origin issues, only cell and assymetric unit. ================================ Jose Antonio Cuesta-Seijo, PhD Carlsberg Laboratory Gamle Carlsberg Vej 10 DK-1799 Copenhagen V Denmark Tlf +45 3327 5332 Email [email protected] ================================ FROM: CCP4 bulletin board [mailto:[email protected]] ON BEHALF OF Eleanor Dodson SENT: Thursday, September 11, 2014 11:44 AM TO: [email protected] SUBJECT: [ccp4bb] making sure related molecules occupy the same space Here is a very common scenario for me. You run several MR jobs, say to search for 2 mols/asymm unit , maybe with different models or using different programs.. You get several solutions, probably on different origins and/or related by some symmetry operator. How best to overlap them? My way is this: Use PISA to assemble all solutions from each run into a compact molecule (It does this by applying allowed symmetry operators.) Calculate SFS from each solution, combine them and use PHASEMATCH to find the origin shift . Move solution two to the same origin as solution one. Now check for fitting - remembering that if both solutions have chains A B there is no guarantee that A2 maps to A1 and B2 to B1. So I superpose A2 onto A1, A2 onto B1 etc till I find a transformation matrix that is indeed a symmetry operator.. (You can do this in coot providing you can find the output matrix on the screen!) Then apply that symmetry to move A2 B2 to overlap A1 B1 ( or maybe B1 A1) as appropriate.. Obviously this is a pain in the neck! Does anyone have a neater solution?? eleanor
