title: Catalytic function of the mycobacterial binuclear iron monooxygenase in acetone metabolism.
abstract: Mycobacteria such as Mycobacterium smegmatis strain mc(2)155 and Mycobacterium goodii strain 12523 are able to grow on acetone and use it as a source of carbon and energy. We previously demonstrated by gene deletion analysis that the mimABCD gene cluster, which encodes a binuclear iron monooxygenase, plays an essential role in acetone metabolism in these mycobacteria. In the present study, we determined the catalytic function of MimABCD in acetone metabolism. Whole-cell assays were performed using Escherichia coli cells expressing the MimABCD complex. When the recombinant E. coli cells were incubated with acetone, a product was detected by gas chromatography (GC) analysis. Based on the retention time and the gas chromatography-mass spectrometry (GC-MS) spectrum, the reaction product was identified as acetol (hydroxyacetone). The recombinant E. coli cells produced 1.02 mM of acetol from acetone within 24 h. Furthermore, we demonstrated that MimABCD also was able to convert methylethylketone (2-butanone) to 1-hydroxy-2-butanone. Although it has long been known that microorganisms such as mycobacteria metabolize acetone via acetol, this study provides the first biochemical evidence for the existence of a microbial enzyme that catalyses the conversion of acetone to acetol.
authors: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan tfuruya@fuji.waseda.jp.
authors: Toshiki
authors: T
authors: Furuya
authors: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors: Tomomi
authors: T
authors: Nakao
authors: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors: Kuniki
authors: K
authors: Kino
mesh_terms: D000096:Acetone / Q000031:analogs & derivatives* / Q000378:metabolism*; D055162:Biocatalysis; D002074:Butanones / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D005798:Genes, Bacterial; D007501:Iron; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D005810:Multigene Family; D020102:Mycobacterium smegmatis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology
chemical_list: D002074:Butanones; D000096:Acetone; C005222:methylethyl ketone; C004433:acetol; D007501:Iron; D006899:Mixed Function Oxygenases; C487002:1-hydroxy-2-butanone
keywords: MimABCD; acetol; acetone; monooxygenase; mycobacteria; oxidation