Nitrous Oxide Reductase

Abstract

(N 2 O) is a major greenhouse gas and is thought to be some 300 times more potent than CO 2 in promoting global warming due to its inert chemical nature. The difficult chemistry of N 2 O reduction to gaseous nitrogen (N 2 ) in biology is catalyzed by the novel µ 4 ‐sulfide‐bridged tetranuclear Cu z cluster of the N 2 O reductases (N 2 ORs). These enzymes, in common with cytochrome c oxidase (CCO), also contain an electron‐donating Cu A site. During the past five years, several structures of this enzyme, from a number of species, have emerged, providing the details of structural elements responsible for this fascinating chemistry. These aspects are discussed in the light of extensive spectroscopic and functional data, providing an up‐to‐date review from these perspectives.