Something to think about in using ensembles for refinement: Even in ultra high resolution crystal structures, usually only a single conformation for MC (maybe dual in some places) is seen and maybe 2-3 conformations for many SCs. Occupancies of these SCs can be adjusted during refinement with even the lowest occupany ones ending up with something like 0.1-0.2 occ. In that case, what extra knowledge is gained by modeling 5 or more ensembles other that possibly some lowering of R/Rf (which in itself may be justifiable since lower R/Rf ==> higher model accuracy). -Debanu.
-----Original Message----- From: CCP4 bulletin board on behalf of Bryan W. Lepore Sent: Fri 3/28/2008 8:57 AM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Model ensemble for x-ray crystallography > At 10:13 AM 3/28/2008, Lucas Bleicher wrote : >> Some time ago I've heard about the idea of proposing an ensemble of >> models (as in NMR), instead of a single model for x-ray crystallography >> structures. If I remember correctly, this idea has been published >> somewhere. Can anyone tell me what article is that? jmb 301 1237-1256, 2000 analyzes the disorder in calmodulin that considers such a treatment along with other models of disorder. http://www.ncbi.nlm.nih.gov/pubmed/10966818 -bryan
