Metallocenter assembly in nickel-containing enzymes

Abstract

 The five known nickel-dependent enzymes include urease, hydrogenase, carbon monoxide dehydrogenase (and CO dehydrogenase/acetyl-coenzyme A synthase), methyl-S–coenzyme M reductase, and one class of superoxide dismutase. Consistent with their disparate functions, these Ni enzymes have distinct metallocenter structures that vary in Ni coordination geometry, number and types of metals, and the presence of additional components. Sophisticated cellular Ni processing systems have been devised to allow for specific and functional incorporation of Ni into these proteins. This review highlights several themes that are common to the enzyme activation processes and summarizes current concepts related to the enzyme-specific Ni assembly pathways.