Hello all,
I'm just finishing up my first structure, a membrane protein with 5
fold NCS. The native dataset is good to about 2.1A. The R factors are good,
around .22/.26 without waters. The only problem is that I'm having a
difficult time fitting what looks to be a very important (potential binding
site) loop region of about 20 AA or so because the density is poor. I have
relied heavily on the NCS to solve the rest of the structure, but releasing
the constraints doesn't particularily help. I can see green blobs here and
there in the difference map, and there is some continuous density at .8
sigma but its much poorer than the rest of the protein. (which is also
mostly alpha helical) I would imagine that this is a common problem and am
wondering if there are any tips from the experts seeing as I am extremely
new to this. Thank you all, I have already learned a great deal from this board.
Drew
P.S. I have been using CCP4, Coot, Refmac, DM, Resolve (for dm), and Phenix
refine
