Nitrile hydratases (NHase) EC:4.2.1.84 are unusual metalloenzymes that catalyse the hydration of nitriles to their corresponding amides. They are used as biocatalysts in acrylamide production, one of the few commercial scale bioprocesses, as well as in environmental remediation for the removal of nitriles from waste streams. Nitrile hydratases are composed of two subunits, alpha and beta, and they contain one iron atom per alpha beta unit [1]. Beta subunit consists of an N-terminal helical domain and a C-terminal SH3-like domain (represented in this entry) [2,3]. Thiocyanate hydrolase (SCNase) is a member of the NHase family, comprises alpha, beta and gamma subunits which share amino acid sequence similarities with NHase beta subunit C-terminal, beta subunit N-terminal and NHase alpha subunit, respectively [3].

1: Crystal structure of nitrile hydratase reveals a novel iron centre in a novel fold. Huang W, Jia J, Cummings J, Nelson M, Schneider G, Lindqvist Y; Structure 1997;5:691-699. PMID:9195885

2: Mutational and structural analysis of cobalt-containing nitrile hydratase on substrate and metal binding. Miyanaga A, Fushinobu S, Ito K, Shoun H, Wakagi T; Eur J Biochem. 2004;271:429-438. PMID:14717710

3: Structure of thiocyanate hydrolase: a new nitrile hydratase family protein with a novel five-coordinate cobalt(III) center. Arakawa T, Kawano Y, Kataoka S, Katayama Y, Kamiya N, Yohda M, Odaka M; J Mol Biol. 2007;366:1497-1509. PMID:17222425