NCS - inter-protomer ligands

[s_aarono at EDUSERV.ITS.UNIMELB.EDU.AU]

> I am trying to set up strict NCS but have encountered a problem.
> I have a metal site at the protomer interface which is ligated
> by one of the residues in the symmetry mate.
> 
> How do I go about telling XPLOR that it is the residue in the
> symmetry mate that is ligated and not the one in the protomer?
> 
> Thanks for any help,

A quick-and easy way might be to set up ncs-restraints instead of
strict ncs and have a high restraint weight (1000-2000 kcal/A^2).
The metal interactions should then be straight forward.  You can use freeR to
see if you are over-fitting. What resolution are you at?

Hope this Helps

Aaron