Dear all,
I am refining a structure at 2.0 A. The water molecules have been added using arp/warp resulting Rwork/Rfree=21/26% (about 370 HOH for 360 residues). After 10 cycles of refmac refinement (wt 0.3), Rwork/Rfree went up about 1.5% to 22.5/27.5%. I did some minor adjustments and add/delete water in Coot followed by 10 cycles refmac refinement, but Rwork/Rfree are still around 22.5/27.5%. I also noticed a few side chains without density. Will setting those atoms to 0 occupancy or high B factor or mutating to Ala help decrease Rfree substantially? If not, is there any better strategies to lower down R factors? I will be very appreciative if you have any suggestions or comments to offer. Thank you in advance. Best, Joe
