Structure and Function of Copper Nitrite Reductase
Copper-containing nitrite reductase (CuNiR) catalyses the one-electron reduction of nitrite to nitric oxide in the denitrification pathway. Two types of copper-binding site cooperatively function in the enzyme for effective chemical reaction, electron transfer and nitrite reduction. Study of this enzyme began more than 50 years ago and important developments continue to be made. Recent experimental and computational results have revealed further details of the chemical processes. This chapter discusses the latest results in the context of the structural and functional relationships of this enzyme. In particular, knowledge of the metal-binding sites has expanded to the second coordination spheres. A comprehensive scrutiny of the data provided by both pioneering and recent workers has shed light on the still unexplained mechanism of CuNiR.