Particulate methane monooxygenase

Nguyen H-HT, AK Shiemka, S J Jacobs, BJ Hales, ME Lidstrom, S 1 Chan (1994) The nature of the copper ions in the membranes containing the particulate methane monooxygenase from Methylococcus capsu-latus (Bath). J Biol Chem 269 14995-15005. 

Sontoh S, JD Semrau (1998) Methane and trichloroethylene degradation by Methylosinus trichosporium OB3b expressing particulate methane monooxygenase. Appl Environ Microbiol 64 1106-1114. 

H. H. T. Nguyen, S. J. Elliott, J. H. K. Yip, S. I. Chan (1998) The particulate methane monooxygenase from Methylococcus capsulatus (Bath) is a novel copper-containing three-subunit enzyme - Isolation and characterization. J. Biol. Chem., 273 7957-7966... 

N. N. Shah, M. L. Hanna, K. J. Jackson, R. T. Taylor (1995) Batch cultivation of Methylosinus trichosporium OB3b. 4. Production of hydrogen-driven soluble or particulate methane monooxygenase activity. Biotechnol. Bioeng., 45 229-238... 

Usually, these metalloproteins contain both type 2 and type 3 copper centers, together forming a triangular-shaped trinuclear active site, such as found in laccase (polyphenol oxidase) [38-41] and ascorbate oxidase (3) [42]. Recent evidence for a related arrangement has been reported for the enzyme particulate methane monooxygenase as well [43], but in this case the Cu Cu distance of the type 2 subunit (2.6 A) appears to be unusually short and the third Cu ion is located far from the dinuclear site. 

Itoh et al. used Cu yd-diketiminato complexes with general formula 4, and their reactivity has been described as a functional model for pMMO (particulate methane monooxygenase). Initially, the Hgands were reacted with both Cu and Cu precursors, with a variety of species formed, depending on the specific conditions employed [111, 112]. It was then shown that both Cu and Cu complexes ultimately led to bis(/z-oxo)(Cu )2 species upon reaction with O2 and H2O2, respectively. Use of these Cu complexes as the pre-catalysts for the oxidation of alkanes (cyclohexane and adamantane) in the presence of H2O2 resulted in low yields ( 20%). 

Burrows, K. J., A. Cornish, D. S. Scott, and I. J. Higgins, Substrate specificities of the soluble and particulate methane monooxygenases of Methylosinus trichosporium OB3b. Mol. Microbiol., 6, 335-342 (1984). 

Evidence for a Diiron Center in Particulate Methane Monooxygenase... 

Lieberman, R. L. Shrestha, D. B. Doan, P. E. Hoffman, B. M. Stemmier, T. L. Rosenzweig, A. C. Purified particulate methane monooxygenase from Methylococcus capsulatus (Bath) is a dimer with both mononuclear copper and a copper-containing cluster. Proc. Natl. Acad. Sci. USA 2003, 100(1), 3820-3825. 

Takeguchi, M. Miyakawa, K. Okura, I. Purification and properties of particulate methane monooxygenase from Methylosinus trichosporium OB3b. J. Mol. Catal. A 1998, 132 (2-3), 145-153. 

Kitmitto, A. Myronova, N. Basu, R Dalton, H. Characterization and structural analysis of an active particulate methane monooxygenase trimer from Methylococcus capsulatus (Bath). Biochemistry 2005, 44(33), 10954-10965. 

Holmes, A.J., Costello, A., Lidstrom, M.E., and Murrell, J.C. (1995) Evidence that particulate methane monooxygenase and ammonia monooxygenase may be evolutionary related. FEMS Microbial. Lett. 132, 203-208. 

D = e Donor) nitric oxide synthase particulate-methane monooxygenase (23)... 

Nguyen, H. H., Nakagawa, K. H., Hedman, B., Elliott, S. J., Lidstrom, M. E., Hodgson, K. O., and Chan, S. L, 1996, X-ray absorption and EPR studies on the copper ions associated with the particulate methane monooxygenase from Methylococcus capsulatus (Bath)6 Cu(I) Ions and their implications, J. Am. Chem. Soc. 118 12766nl2776. 

Additional intense pre-edge features can be observed for other first-row transition metals. In cuprous containing systems, this feature arises from the Is 4p transition. As with the Is 3d transition, the intensity of the Is 4p transition depends on the coordination number and symmetry of the cuprous metal site. " A weak Is 3d transition can also be observed for cupric systems. Our laboratory has successfully applied the methodology of quantitating both Is 3d and the Is 4p transition areas to elucidate the complex mixed valence copper environment in the multicopper active sites in particulate methane monooxygenase. ... 

McDonald I. R. and Murrell J. C. (1997) The particulate methane monooxygenase gene pmoA and its use as a functional gene probe for methanotrophs. FEMS Microbiol. Lett. 156, 205-210. 

Methane is oxidized under aerobic conditions by a group of bacteria called methanotrophs. These widespread bacteria play an important role in the global cycling of methane. Two types of methane oxidation systems are known, a ubiquitous particulate methane monooxygenase (pMMO) and a cytoplasmic soluble methane monooxygenase (sMMO) found in only a few strains. These enzymes have different catalytic characteristics, and so it is important to know the conditions under which each is expressed. In those strains containing both sMMO and pMMO, the available copper concentration controls which enzyme is expressed. However, the activity of the pMMO is also affected by copper. Data on methane oxidation in natural samples suggest that methanotrophs are not copper-limited in nature and express the pMMO predominantly. 

To understand the role of these bacteria in methane cycling, the methane oxidation system must be studied. In methanotrophs, methane is oxidized to methanol by an enzyme called the methane monooxygenase (MMO) (I), which uses methane, molecular oxygen, and reducing equivalents to produce methanol and water. All known methanotrophs contain a membrane-bound MMO, called the particulate methane monooxygenase (pMMO). The presence of this enzyme system is correlated with the complex internal membrane system found in all known methanotrophs. 

Himes, R. A., Karlin, K. D. (2009). Copper-dioxygen complex mediated C—H bond oxygenation relevance for particulate methane monooxygenase (pMMO). Current Opinion in Chemical Biology, 13, 119—131. 

Methanotrophs synthesize both soluble (sMMO) and particulate (pMMO) monooxygenases and the synthesis of the particulate methane monooxygenase is determined by the concentration of Cu in the medium this is noted again in Chapter 5, Section 5.2.4. 

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