The present generation of high throughput structural biologists stays on the intellectual shoulders of the giants of crystallography from past days (modifying GOOGLE). In the military jargon, in the constant wars with the structures, situation described in this exchanges is called encounter. To know all this - is as to know how to calculate without computers. Or to have Mentates to navigate in space without computer technology which is presently prohibited after attempts of computers to take over (citing Dune).
Dr Felix Frolow Professor of Structural Biology and Biotechnology Department of Molecular Microbiology and Biotechnology Tel Aviv University 69978, Israel Acta Crystallographica F, co-editor e-mail: mbfro...@post.tau.ac.il Tel: ++972-3640-8723 Fax: ++972-3640-9407 Cellular: 0547 459 608 On Aug 20, 2010, at 19:42 , Clemens Vonrhein wrote: > Dear Eleanor at al, > > On Fri, Aug 20, 2010 at 05:20:05PM +0100, Eleanor Dodson wrote: >> There is quite a lot of background to these Qs in a variwty of text >> books, and something on this website. >> http://www.ccp4.ac.uk/dist/html/pxmaths/index.html > > Nice page :-) > >> When changing hand you need to consider whether this also involves a >> change of spacgroup; eg P32 instead of P31 > > It always does involve a change to the enantiomorph. One only ever > needs to check two solutions: > > * if you started with your dataset in P31 you will have to check > > (X,Y,Z) P31 and (-X,-Y,-Z) P32 > > and never: (-X,-Y,-Z) P31 > > * if you started with P32 just check > > (X,Y,Z) P32 and (-X,-Y,-Z) P31 > > and never: (-X,-Y,-Z) P32 > > It helps to process data always in the same enantiomorph spacegroup > (since the extinction rules are identical): e.g. sticking with P61 and > P62 at the beginning and never go into P65 and P64 for a start (only > after phasing or MR points to that spacegroup). > > Cheers > > Clemens > > -- > > *************************************************************** > * Clemens Vonrhein, Ph.D. vonrhein AT GlobalPhasing DOT com > * > * Global Phasing Ltd. > * Sheraton House, Castle Park > * Cambridge CB3 0AX, UK > *-------------------------------------------------------------- > * BUSTER Development Group (http://www.globalphasing.com) > ***************************************************************
