26 and 33 tells me you are over fitting your structure the spread is more than 5% If there is a ligand added and it really doesn't look like a good fit i would try work on it (remove it and look at alternatives) When you refine you may use NCS if you have (NCS in your structure)
If there is a better resolution structure available or not run the lorestr even your resolution is not a low resolution Also i will look at the Ramachandran outliers, geometry validation, and rotomer outlier checks very thoroughly and will spend all the efforts to make the structure stick to the conventions Try Zanuda and see if your space group symmetry is right and it will try higher symmetry or lower symmetry in your space group and run refinement and provide to if you are refining the structure in the correct space group If you find higher or lower symmetry as judged by R and Rfree of its refinements i will go and refine it in all different space groups and see which give me better R and R free spread In any case i am 99% sure you are over fitting your density to what you want to see and thus being very biased which is very problematic Best Pius On Wed, Dec 14, 2016 at 7:02 AM, 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 > -- P
