Zinc coordination, function, and structure of zinc enzymes and other proteins

A perspective on the biological occurrence and role of zinc should not only seek out the generalizations that are now apparent but should also call attention to the participation of zinc in metabolic processes, the bases of which have yet to be explained. The authors therefore highlight the salient accomplishments of the past two decades, achieved primarily through the study of zinc enzymes, while calling attention to the urgent but unanswered questions regarding the functions of zinc in metallothionein and DNA-binding proteins. The authors first consider the 12 zinc enzymes whose crystal structures are known and are now the standards of reference for catalytically active and structural zinc sites.