Re: [ccp4bb] Temperature factor discrepancy

[Wim Burmeister]

I should have given the precision that the problem remains unaffected by a change of the resolution range (even if I use for example only 4.5 to 3 A resolution). I am not using TLS and the data are quite isotropic. Rcryst values are as expected for such a structure. Anopther 3.5 A dataset does not show the problem (right column). Wilson plot B-factor [Å2] 66 43 Refinement     Rcryst 0.186 (0.259) 0.190 (0.239) Rfree 0.268 (0.408) 0.256 (0.278) Rms deviations from ideal bondlengths (Å) 0.020 0.018 Rms deviations from ideal bond angles (°) 2.0 1.9 Average B-factor [Å2] 39 46 Values for the highest resolution bin are given in brackets. Cheers Wim Wim Burmeister a écrit : Dear all, I have a 3 A structure refined with REFMAC which gives consistently average atomic B-factors of 40 A2, whereas the B factor from a Wilson plot is about 60 A2. Is there any explanation for such a discrepancy? There are no obvious problems: No twinning, spacegroup P21 with two molecules in the asu, no proper ncs symmetry. No pathologic Wilson plot, complete and redundant dataset (although collected on several crystals with serious problems due to radiation damage). Interestingly, the Wilson plot of the Fcalc values is about 60 A2 as for Fobs in the output dataset. Yours Wim -- ******************************************************************************* Wim Burmeister Professeur, Membre de l'Institut Universitaire de France Unit of Virus Host Cell Interactions (UVHCI) UMR5233 UJF-EMBL-CNRS 6 rue Jules Horowitz B.P. 181, F-38042 Grenoble Cedex 9 FRANCE E-mail: [EMAIL PROTECTED] Tel: +33 (0) 476 20 72 82 Fax: +33 (0) 476 20 94 00 http://www.uvhci.fr *******************************************************************************