Thank you Charles for the kind explanation. I am already looking forward to
your implementation of NCS potentials in ensembles.
Best regards,
Marcel
Marcel Jurk
Leibniz-Institut fuer Molekulare Pharmakologie (FMP)
Solution NMR (AG Schmieder)
Robert-Roessle-Str. 10
13125 Berlin
Germany
eMail: jurk at fmp-berlin.de
Phone: +49-30-94793223
Fax: +49-30-94793169
>>> Charles Schwieters <charles at schwieters.org> 03/29/12 5:44 PM >>>
Hello Marcel--
>
> I was trying to do an ensemble refinement of a dimeric structure and
> keep getting the following error message. Is the NCS potential the
> only one that's not supported in ensemble mode or am I missing any
> kind of additional function to call before the set-up of the NCS
> potential?
For symmetric dimers, usually two terms are used in single structure
calculations, an ``NCS'' term to force the subunits to be identical
and a distance symmetry term to enforce C2 symmetry. These terms can
be used in ensemble calculations to force each ensemble *member* to have
these properties, however this is over-restraining the system, as, in
general, only the overall ensemble requires these symmetries. In
the latest Xplor-NIH release, the distance symmetry term can be used
to restrain the average ensemble position using the setup below. There
currently is no term for the NCS portion- I happen to be working on it
now and hope to have something working by next week.
best regards--
Charles
from distSymmTools import create_DistSymmPot, genDimerRestraints
dSymmP = create_DistSymmPot('dSymmP')
for r in genDimerRestraints(segids=['A','B'],
#specify appropriate range
resids=range(10,150,10)):
dSymmP.addRestraint(r)
pass
dSymmP.setShowAllRestraints(True)
dSymmP.setEnsembleAveType("average")
potList.append(dSymmP)
