title: Characterization and Crystal Structure of a Robust Cyclohexanone Monooxygenase.
abstract: Cyclohexanone monooxygenase (CHMO) is a promising biocatalyst for industrial reactions owing to its broad substrate spectrum and excellent regio-, chemo-, and enantioselectivity. However, the low stability of many Baeyer-Villiger monooxygenases is an obstacle for their exploitation in industry. Characterization and crystal structure determination of a robust CHMO from Thermocrispum municipale is reported. The enzyme efficiently converts a variety of aliphatic, aromatic, and cyclic ketones, as well as prochiral sulfides. A compact substrate-binding cavity explains its preference for small rather than bulky substrates. Small-scale conversions with either purified enzyme or whole cells demonstrated the remarkable properties of this newly discovered CHMO. The exceptional solvent tolerance and thermostability make the enzyme very attractive for biotechnology.
authors.affiliation: Department of Biotechnology, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands.
authors.forename: Elvira
authors.identifier: 0000-0003-4199-9458
authors.initials: E
authors.lastname: Romero
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Ferrata 9, 27100, Pavia, Italy.
authors.forename: J Rubén Gómez
authors.identifier: 0000-0003-2723-4096
authors.initials: JR
authors.lastname: Castellanos
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Ferrata 9, 27100, Pavia, Italy.
authors.forename: Andrea
authors.identifier: 0000-0002-9523-7128
authors.initials: A
authors.lastname: Mattevi
authors.affiliation: Department of Biotechnology, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands.
authors.forename: Marco W
authors.identifier: 0000-0001-6346-5014
authors.initials: MW
authors.lastname: Fraaije
mesh_terms: D000192:Actinomycetales / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D018360:Crystallography, X-Ray; D003512:Cyclohexanones / Q000378:metabolism; D004795:Enzyme Stability; D007659:Ketones / Q000378:metabolism; D008958:Models, Molecular; D010105:Oxygenases / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D013237:Stereoisomerism; D013379:Substrate Specificity; D013440:Sulfides / Q000378:metabolism
chemical_list: D003512:Cyclohexanones; D007659:Ketones; D013440:Sulfides; C036468:cyclohexanone; D010105:Oxygenases; C019961:cyclohexanone oxygenase
keywords: Baeyer-Villiger oxidation; biocatalysis; cyclohexanone monooxygenase; enzyme stability; ϵ-caprolactone