Hi,
I am refining a structure at 2.1 A that has a Phosphate (or fosfate)
bound to a Zn atom. The Zn-OPO3 distance and esd are defined in a dictionary
file that is read by refmac. The refinement seems to drag the O of PO4 too
close to the Zn (d ~ 1.6 A). The dictionary entry for this distance is 1.99 A. In
order to force the refinement to closely adhere to the dictionary ideal value
of distance, I tried varying the esd, but without any significant improvement.
The Zn-PO4 link is also defined in the PDB
file as a LINK record.
My question is: how do I constrain the
distance more forcefully?
Is there an alternative method?
Thanks
Abhinav
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Abhinav Kumar, Ph. D.
Plexxikon,
Inc.
91 Bolivar Dr.
Suite A Tel: 510.647.4021
Berkeley, CA
- 94710 Fax: 510.548.4785
akumar@plexxikon.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
