EDSTATS is part of CCP4
.which in fact I cite in 33% of all of its CrossRef references http://scripts.iucr.org/cgi-bin/citedin?dz5235/ Touché. From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Frank von Delft Sent: Dienstag, 4. Februar 2014 14:40 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] high Rwork / Rfree after MR And really we should not be using real space CC or real space R anymore - not since Tickle 2012 (http://scripts.iucr.org/cgi-bin/paper?S0907444911035918) EDSTATS is part of CCP4. phx On 04/02/2014 13:31, Bernhard Rupp wrote: > interpretable electron density map is obtained to which most of your protein model can be fitted properly. The primary numeric indication for that are your R-factors. Minor comment: The measure for the fit of the *model (density) to the electron density* is actually a local real space correlation coefficient or a local real space R value, not the global reciprocal space R-values (not a *factor* in the mathematical sense, nor a factor for anything else). The overall linear residual between model structure factor amplitudes Fc and observed amplitudes Fo (aka R(F)-value) is a global reciprocal space measure, which can be affected by many other contributions causing the misfit between Fo and Fc data, in addition to bad model, as already noted below. Ø The high values you have suggest that either something is wrong with your space group, twinning, etc. as Eleanor suggested, or your space group and MR solution may be still correct but for a search model of poor similarity with your crystal structure. Even in the later case, at this resolution it is going to be very challenging to build and refine a structure to reasonable R-factors starting from a poor model. Hay ======================================== Hay Dvir Ph. D. Head Technion Center for Structural Biology Technion Haifa 3200003, Israel Tel: +(972)-77-887-1901 Fax: +(972)-77-887-1935 E-mail hd...@technion.ac.il Website http://tcsb.technion.ac.il/Hay-Dvir ======================================== On Feb 4, 2014, at 11:36 AM, Shanti Pal Gangwar wrote: Dear All I have solved one structure by MR. The data data quality was poor so the Rmerge was high. The resolution of the data is 3.3 Angstrom.The refinement statistics are also very poor Rw/Rf= 40/42 %. After many efforts we are not able to get reasonable Rw/Rf. My question is "can it be claimed that we have solved the structure?" Thanks in advance -- ******************** regards Shanti Pal Gangwar School of Life Sciences Jawaharlal Nehru University New Delhi-110067 India Email:gangwar...@gmail.com <mailto:email%3agangwar...@gmail.com>
