Crystallographic refinement of ligand complexes

Abstract

Methods and resources for obtaining chemically plausible starting models and restraint sets for refinement of ligand complexes are described and some of the potential pitfalls are discussed.

Abstract

Model building and refinement of complexes between biomacromolecules and small molecules requires sensible starting coordinates as well as the specification of restraint sets for all but the most common non-macromolecular entities. Here, it is described why this is necessary, how it can be accomplished and what pitfalls need to be avoided in order to produce chemically plausible models of the low-molecular-weight entities. A number of programs, servers, databases and other resources that can be of assistance in the process are also discussed.