There are 3 options: 1) Use molrep. If you have two copies related with PST then it can give right solution 2) Take the latest version of phaser and use it. It can deal with PST with two related copies also 3) Reduce cell dimensions (it does not seem to be possible in your case. PST is not exactly on cell edges. But you can try). Work in c2 with smaller cell and then expand.
but before going into all these trouble make sure that you really have PST. Calculating patterson (ccp4i, fft) and displaying using coot can give you some insight. Relation between origin and non-origin peaks can give you some insight. regards Garib On 13 Mar 2012, at 10:21, vincent Chaptal wrote: > Dear ccp4, > > I have a case of PTS and wonder what's the best strategy to handle my data. > > I processed my data in C2 with a=161 b=109 c=225 beta=104. The data in 97% > complete to 3,8A. > xtriage detected a 40% peak in the patterson at fractional coordinates > x=-0,001 y=0,055 z=0,5. > > I want to try to phase using MR. > Should I: > - leave the data in C2 (fully complete) and specify the program to use PST. > - expand from C2 to P1 and run using PST. > - re-index in P1 (a=98 b=97 c=225, alpha=78 beta=78, gamma=68) with only ca. > 80% completeness, and specify PST. > > before shooting more crystals to increase compleness and going for HA > phasing, i was wondering if i could do something with what i have. > thank you for your input. > vincent > > > -- > Vincent Chaptal, PhD > Institut de Biologie et Chimie des Protéines > Drug-resistance modulation and mechanism Laboratory > 7 passage du Vercors > 69007 LYON > FRANCE > +33 4 37 65 29 01 > http://www.ibcp.fr > Garib N Murshudov Structural Studies Division MRC Laboratory of Molecular Biology Hills Road Cambridge CB2 0QH UK Email: ga...@mrc-lmb.cam.ac.uk Web http://www.mrc-lmb.cam.ac.uk
