es - look carefully at your data quality indicators - batch scales, Wilson plot - moments etc.. tHese can show up if there is a problem with ice rings or crystal decay or whatever. Then I always look at the REFMAC plot of <Fobs> v <Fcalc> If they overlap well - good - but problems with scaling will show up there.
Eleanor On 14 December 2016 at 15:21, Mark J van Raaij <[email protected]> wrote: > Dear Rohit, > > I wouldn’t judge a structure just by the Rwork and Rfree values, but also > by the validation and other statistics (bond lengths, angles, Ramachandran > plot, map quality, fit to map, average B values). If these are all ok, you > should be able to “get away with” an Rfree of 33%. > In your email you state that you have already made a significant effort in > different refinement strategies, so perhaps there is no improvement to be > made there. > The reason for the high-ish Rfree could be that the data is not so good, > and reprocessing might help. Although the most likely outcome is that you > can’t significantly improve it, but at least trying will put your mind more > at ease. > In the end, the only way to improve the structure, and R-factors, may be > to grow a better crystal, cryo-protect better and/or collect better data - > this particular crystal may just have some kind of disorder. > > Greetings, > > Mark J van Raaij > Dpto de Estructura de Macromoleculas > Centro Nacional de Biotecnologia - CSIC > calle Darwin 3 > E-28049 Madrid, Spain > tel. (+34) 91 585 4616 > http://wwwuser.cnb.csic.es/~mjvanraaij > > > > > > > > > On 14 Dec 2016, at 16:02, rohit kumar <[email protected]> wrote: > > > > Dear All, > > > > I am solving a data of 2.5 A (C121 space group). Right now the R/Rfree > values are 26/33, after many cycles of refinements (With or With out water) > the R/Rfree values still same. Zanuda suggests that the space group seems > to be correct and the model is looking fine in coot. > > Some one suggest what is the main problem. > > Should I again process my data? And what is the best way to fine right > space group (If problem with space group). > > Please tell me if you need any information regarding may data. > > > > -- > > WITH REGARDS > > Rohit Kumar Singh > > Lab. no. 430, > > P.I. Dr. S. Gourinath, > > School of Life Sciences, > > Jawaharlal Nehru University > > New Delhi -110067 >
