[log in to unmask]" type="cite">

Hi

Am trying to build coordinated Zn+2 by CYS -SG atoms and have it
refine properly in refmac5.5

I added ZN ions in Coot at the Fo-Fc peaks. Then I defined manually
the coordination relations in a text editor using LINK records.
the ions were placed in the same chain that was doing the coordination.

LINK        ZN    ZN A1001                 SG  CYS A 487     1555   1555  2.34

I found that some of these ions refined well using refmac 5.5 and the
resulting pdb had LINKR records in place indicating the coordinating
interactions.

For some of the Zn atoms however , the ions did refine , but coot
still was covalently disulphide bonding the Cys to each other rather
than coordinating the ZN and there were no LINKR records in the refmac
refined pdb file. I know these interactions are legitimate because it
is a known structure.Should I manually create LINKR records instead of
LINK records after modeling in the ions?

What is the correct procedure to model coordinating ions and have
refmac treat them appropriately.
Thanks in advance.

Hari