Purification and characterization of dimethylsulfide monooxygenase from hyphomicrobium sulfonivorans
Boden, Rich, Borodina, E., Wood, A. P., Kelly, D. P., Murrell, J. C. (J. Colin) and Schäfer, Hendrik. (2011) Purification and characterization of dimethylsulfide monooxygenase from hyphomicrobium sulfonivorans. Journal of Bacteriology, Vol.193 (No.5). pp. 1250-1258. ISSN 0021-9193Full text not available from this repository.
Official URL: http://dx.doi.org/10.1128/JB.00977-10
Dimethylsulfide (DMS) is a volatile organosulfur compound which has been implicated in the biogeochemical cycling of sulfur and in climate control. Microbial degradation is a major sink for DMS. DMS metabolism in some bacteria involves its oxidation by a DMS monooxygenase in the first step of the degradation pathway; however, this enzyme has remained uncharacterized until now. We have purified a DMS monooxygenase from Hyphomicrobium sulfonivorans, which was previously isolated from garden soil. The enzyme is a member of the flavin-linked monooxygenases of the luciferase family and is most closely related to nitrilotriacetate monooxygenases. It consists of two subunits: DmoA, a 53-kDa FMNH(2)-dependent monooxygenase, and DmoB, a 19-kDa NAD(P) H-dependent flavin oxidoreductase. Enzyme kinetics were investigated with a range of substrates and inhibitors. The enzyme had a K(m) of 17.2 (+/- 0.48) mu M for DMS (k(cat) = 5.45 s(-1)) and a V(max) of 1.25 (+/- 0.01) mu mol NADH oxidized min(-1) (mg protein -1). It was inhibited by umbelliferone, 8-anilinonaphthalenesulfonate, a range of metal-chelating agents, and Hg(2+), Cd(2+), and Pb(2+) ions. The purified enzyme had no activity with the substrates of related enzymes, including alkanesulfonates, aldehydes, nitrilotriacetate, or dibenzothiophene-sulfone. The gene encoding the 53-kDa enzyme subunit has been cloned and matched to the enzyme subunit by mass spectrometry. DMS monooxygenase represents a new class of FMNH(2)-dependent monooxygenases, based on its specificity for dimethylsulfide and the molecular phylogeny of its predicted amino acid sequence. The gene encoding the large subunit of DMS monooxygenase is colocated with genes encoding putative flavin reductases, homologues of enzymes of inorganic and organic sulfur compound metabolism, and enzymes involved in riboflavin synthesis.
|Item Type:||Journal Article|
|Subjects:||Q Science > QP Physiology
Q Science > QR Microbiology
|Divisions:||Faculty of Science > Life Sciences (2010- )|
|Library of Congress Subject Headings (LCSH):||Dimethyl sulfide, Monooxygenases, Microbial metabolism, Biogeochemistry|
|Journal or Publication Title:||Journal of Bacteriology|
|Publisher:||American Society for Microbiology|
|Page Range:||pp. 1250-1258|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Natural Environment Research Council (Great Britain) (NERC)|
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