Sang Hoon, Each molecule in the asymmetric unit is most likely different. I work on a protein that crystallizes as a homodimer with 2 molecules per asymmetric unit and there are some differences between the two (eg: electron density visible for the 14 N-terminal residues in one molecule, but not the other).
Cheers, Jim On Tue, Mar 24, 2009 at 11:03 AM, Folmer Fredslund <folm...@gmail.com>wrote: > Dear Sang > > They are really different! > > And I guess you would probably want to use NCS restraints depending on > your resolution. > > Regards, > Folmer > > 2009/3/24 Sang Hoon Joo <s...@duke.edu>: > > I am refining my crystal structure in which I have two identical > > chains in one asymmetric unit. > > Space group is H32 and each chain yields me a biological trimer as > expected. > > The problem is, do I have to assume they are identical, or they are > > really different. > > After each cycle of refinement, if I try to align two molecules I get > > ~ 0.17 RMSD. > > -- > > Sang Hoon Joo, PhD > > Postdoctoral Associate > > Duke University > > 239 Nanaline H. Duke > > Box 3711, DUMC > > Durham, NC 27710 > > > -- Jim Fairman Graduate Research Assistant Department of Biochemistry, Cellular, and Molecular Biology (BCMB) University of Tennessee -- Knoxville 216-368-3337 jfair...@utk.edu james.fair...@case.edu
