Reintroducing electrostatics into macromolecular crystallographic refinement: application to neutron crystallography and DNA hydration.

ABSTRACT: Most current crystallographic structure refinements augment the diffraction data with a priori information consisting of bond, angle, dihedral, planarity restraints, and atomic repulsion based on the Pauli exclusion principle. Yet, electrostatics and van der Waals attraction are physical forces that provide additional a priori information. Here, we assess the inclusion of electrostatics for the force field used for all-atom (including hydrogen) joint neutron/X-ray refinement. Two DNA and a protein crystal structure were refined against joint neutron/X-ray diffraction data sets using force fields without electrostatics or with electrostatics. Hydrogen-bond orientation/geometry favors the inclusion of electrostatics. Refinement of Z-DNA with electrostatics leads to a hypothesis for the entro

SUBMITTER: Fenn TD 

PROVIDER: S-EPMC3083928 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature