|Gene:||chnB||Accession Number: G-2222 (MetaCyc)|
Species: Acinetobacter sp. NCIMB9871
The enzyme has been isolated and purified 35-fold from Acinetobacter sp. NCIMB9871 and found to be a monomeric flavoprotein, containing one mole of bound FAD per mole protein [Donoghue76]. The enzyme has been extensively studied as a model for Baeyer-Villiger monooxygenases [Ryerson82, Latham86].
The chnB gene encoding the protein has been isolated and overexpressed in Escherichia coli. Initial data suggested that the protein was being expressed efficiently when the fused tac promoter was induced, but was degraded rapidly by the host cell [Chen88]. Improved expression was obtained when the regulatory protein chnR, which is also present on the chn operon, was coexpressed, and when the cells were exposed to cyclohexanone [Iwaki99].
Molecular Weight of Polypeptide: 61.0 kD (from nucleotide sequence), 61 kD (experimental) [Iwaki99 ]
Enzymatic reaction of: cyclohexanone monooxygenase
Synonyms: cyclohexanone 1,2-monooxygenase, cyclohexanone oxygenase, cyclohexanone,NADPH:oxygen oxidoreductase (lactone-forming)
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
The reaction is physiologically favored in the direction shown.
In Pathways: cyclohexanol degradation
pH(opt): 9 [Donoghue76]
Donoghue76: Donoghue NA, Norris DB, Trudgill PW (1976). "The purification and properties of cyclohexanone oxygenase from Nocardia globerula CL1 and Acinetobacter NCIB 9871." Eur J Biochem 63(1);175-92. PMID: 1261545
Iwaki99: Iwaki H, Hasegawa Y, Teraoka M, Tokuyama T, Bergeron H, Lau PC (1999). "Identification of a transcriptional activator (ChnR) and a 6-oxohexanoate dehydrogenase (ChnE) in the cyclohexanol catabolic pathway in Acinetobacter sp. Strain NCIMB 9871 and localization of the genes that encode them." Appl Environ Microbiol 65(11);5158-62. PMID: 10543838
Trower89: Trower MK, Buckland RM, Griffin M (1989). "Characterization of an FMN-containing cyclohexanone monooxygenase from a cyclohexane-grown Xanthobacter sp." Eur J Biochem 181(1);199-206. PMID: 2540966
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