Dear Changyi,
Yes it can. You should have a xxx.cif file which Refmac uses to know
about your ligand. Please have a look at it and check that it is
actually representing the ligand you want to refine. You can
then play with standard deviations in the file to put more weight on
idealised geometry (assuming it is correct!) in case ligand distortion
is caused by limited resolution. In general, if ligand description is
correct playing with SD should not be required. Clearly, make sure
that distortion does not have a functional meaning.
Best
Roberto
On 4 Aug 2010, at 20:15, Changyi Xue wrote:
Dear all,
In my structure, there is a ligand, which contains a sugar
ring. In the process of refinement, refmac always tried to distort
the sugar ring to fit into the density. Is there any way to fix or
restrain the ring conformation more tightly? I know CNS has such
function, just wandering if refmac could do it also.
all suggestions are welcome.
changyi
---
Dr. Roberto Steiner
Randall Division of Cell and Molecular Biophysics
New Hunt's House
King's College London
Guy's Campus
London, SE1 1UL
Phone +44 (0)20-7848-8216
Fax +44 (0)20-7848-6435
e-mail roberto.stei...@kcl.ac.uk