Defining parameters for flexible rings in XPLOR

[Wang]

Hi All

We are trying to refine the structure of a protein and drug complex using
XPLOR. However, the drug contains a 6-membered ring which is quite
flexible, and we do not know whether it is puckering up or puckering down.
Can we define two distinct dihedral angle values in XPLOR instead of a
range?  Is there any ready-made parameter file that solve this problem
(especially for anybody working on sugar)?  I am sure that somebody out
there have encountered a problem like this.  Any response is appreciated

Xu Wang



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