Substrate binding and C-H bond activation in the soluble methane monooxygenase hydroxylase

 The selective oxidation of CH₄ to CH₃OH is a conceptually simple, yet functionally difficult, chemical transformation. In nature, this reaction is performed by methane monooxygenases, the soluble class of which employ carboxylate-bridged dinuclear iron centers to activate dioxygen. The process by which small molecules access the active site of the sMMO hydroxylase, the structures of intermediates in the catalytic reaction cycle, and mechanistic details about the attack on the C–H bond are subjects of intense investigation. In this commentary, we present our current views on exogenous ligand binding and dioxygen activation at the active site and the mechanism of alkane hydroxylation. Received: 20 October 1997 / Accepted: 26 February 1998