Thanks a lot Ethan, I will give it a try.
Best Regards, Hailiang > On Thursday 26 August 2010 11:56:39 am Hailiang Zhang wrote: >> Hi, >> >> I want to refine B factors for several residues only (all the other B >> factors and all coordinates fixed, I know it sounds weird but there is a >> reason to try that). > > Maybe you could tell us what this reason is? > >> Is there anyway CCP4 can do this? Thanks for any suggestions! > > Suggestion 1) > > Calculate structure factors for the entire rest of the model. > Include these as F_partial contributing to the refinement of a model > containing only your residues of interest. In this refinement, > refine only the B terms. > > Caveat: I think you will encounter problems with how to handle > the bulk solvent correction. Perhaps that must be included in > F_partial also, and omitted from the subsequence mini-refinement. > > Suggestion 2) > > - Place your residues of interest in a single TLS group. > - Do not assign any other atoms or residues to a TLS group. > - Refine the entire model using refmac in TLS refinement mode. > Choose 5 or 10 cycles of TLS refinement, but 0 cycles of > coordinate/Biso refinement. Disregard all output other than the > refined TLS description for the B factors in your residues of > interest. > - Use TLSANL to expand the TLS parameters back to individual > Biso if you like. > > > >> >> Best Regards, Hailiang >> > > -- > Ethan A Merritt > Biomolecular Structure Center, K-428 Health Sciences Bldg > University of Washington, Seattle 98195-7742 > >
