The VMD-XPLOR visualization package for NMR structure refinement

In this paper we present the VMD-XPLOR package combining the XPLOR refinement program and the VMD visualization program and including extensions for use in the determination of biomolecular structures from NMR data. The package allows one to pass structures to and to control VMD from the XPLOR scripting level. The VMD graphical interface has been customized for NMR structure refinement, including support to manipulate coordinates interactively while graphically visualizing NMR experimental information in the context of a molecular structure. Finally, the VMD-XPLOR interface is modular so that it is readily transferable to other refinement programs (such as CNS).