Excellent point about R-factors. Indeed, at this resolution they should be quite lower than what you have. Did you: - model solvent? - use anisotropic ADPs? - add H (this alone can drop R by 1-2%)? - model alternative conformations? - How R-factors (Rwork) look in resolution? Pavel
On Mon, Aug 26, 2013 at 10:47 PM, Emily Golden <10417...@student.uwa.edu.au>wrote: > Thanks Yuriy and Pavel, > > at this resolution one would expect R/Rfree to be ~ 10-11%/12-13% assuming > you applied anisotropic B-factor refinement ( and probably having a low > symmetry SG). > R merge of 80% may be OK if I/sig for high res shell is >2. > > Yes, I used anisotropic Bfactors and the space group is P1 21 1. However, > the I/sig is only 1.5 in the highest shell. Cutting the data such that > the I/sig is >2 has improved the R factors. Thank you. > > Maps get worse.... Could it be when you use all resolution range you get > 59% of missing reflections in highest resolution shell filled in with DFc > for the purpose of map calculation? > > Yes! the map that I was looking at was filled. > > Emily > > > On 27 August 2013 09:49, Emily Golden <10417...@student.uwa.edu.au> wrote: > >> Hi All, >> >> I have collected diffraction images to 1 Angstrom resolution to the edge >> of the detector and 0.9A to the corner. I collected two sets, one for >> low resolution reflections and one for high resolution reflections. >> I get 100% completeness above 1A and 41% completeness in the 0.9A-0.95A >> shell. >> >> However, my Rmerge in the highest shelll is not good, ~80%. >> >> The Rfree is 0.17 and Rwork is 0.16 but the maps look very good. If I >> cut the data to 1 Angstrom the R factors improve but I feel the maps are >> not as good and I'm not sure if I can justify cutting data. >> >> So my question is, should I cut the data to 1Angstrom or should I keep >> the data I have? >> >> Also, taking geometric restraints off during refinement the Rfactors >> improve marginally, am I justified in doing this at this resolution? >> >> Thank you, >> >> Emily >> > >
