Methylococcus capsulatus

Dalton H, BT Golding, BW Waters, R Higgins, JA Taylor (1981) Oxidation of cyclopropane, methylcyclopro-pane, and arenes with the mono-oxygenase systems from Methylococcus capsulatus. J Chem Soc Chem Commun 482-483. 

The soluble MMO from Methylococcus capsulatus (Bath) is able to oxidize chloro- and bromomethane—but not iodomethane—with the presumptive formation of formaldehyde (Colby et al. 1977). 

Colby J, DI Stirling, H Dalton (1977) The soluble methane mono-oxygenase of Methylococcus capsulatus (Bath). Its ability to oxygenate -alkanes, -alkenes, ethers, and alicyclic, aromatic and heterocyclic compounds. Biochem J 165 395-401. 

Sessions, A. L., Jahnke, L. L., Schimmelmann, A. and Hayes, J. M. (2002) Hydrogen isotope fractionation in lipids of the methane oxidizing bacterium Methylococcus capsulatus. Geochimica et Cosmochimica Acta 66, 3955. 

R. L. Csaki. Bodrossy, T. Hanczar, J. C. Murrell, K. L. Kovacs (2001) Molecular characterization of a membrane bound hydrogenase in the methanotroph Methylococcus capsulatus (Bath). FEMSMicrobiol. Lett., 205 203-207... 

H. Dalton, B. T. Golding, B. W. Waters, R. Higgins, J. A. Taylor (1995) Oxidations of cyclopropane, methylcyclopropane, and arenes with the mono-oxygenase system from Methylococcus capsulatus. J. Chem. Soc. Chem. Commun., 1981 482-483... 

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... 

S. H. Stanley, H. Dalton (1992) The biotransformation of propylene to propylene oxide by Methylococcus capsulatus (Bath) 1. Optimization of rates. Biocatalysis, 6 163-175... 

Copper enzymes are involved in reactions with a large number of other, mostly inorganic substrates. In addition to its role in oxygen and superoxide activation described above, copper is also involved in enzymes that activate methane, nitrite and nitrous oxide. The structure of particulate methane mono-oxygenase from the methanotrophic bacteria Methylococcus capsulatus has been determined at a resolution of 2.8 A. It is a trimer with an a3P33 polypeptide arrangement. Two metal centres, modelled as mononuclear and dinuclear copper, are located in the soluble part of each P-subunit, which resembles CcOx subunit II. A third metal centre, occupied by Zn in the crystal, is located within the membrane. 

The molecular structure of the active site of the monooxygenase isolated from Methylococcus capsulatus is shown in Figure l.1... 

Synecnocystis Chlorobium tepidum Methylococcus capsulatus Rhodobacter capsulatus Rhosdospirillum rubrum Chloroflexus aurantiacus Fibrobacter succinogenes Thermoanaerobacter tengcongensis... 

The presence or absence of Ca + ions in one or both sites also appears to effect the reduction potential of the high-potential heme. In equilibrium redox titrations monitored spectroscopically, done in the presence of Ca + ions, this is shifted positive by about 50 mV PP = - - 226 mV) compared with titrations done in the presence of a chelator (IP = -1-176 mV) (52). This former value is close to the reduction potentials reported for the high-potential heme in the CCP from P. aeruginosa (51), but about 200 mV lower than reported for the high-potential hemes in the enzymes from N. europea (46) and Methylococcus capsulatus Bath (80). In contrast, the reduction potential of the peroxidatic heme is unaffected by the presence or absence of Ca + ions (16, 52). 

Cyclopropanes have been used to test the reactivity of oxidizing enzymes. Thus, while the monooxygenase enzyme from Methylococcus capsulatus oxidizes cyclopropane 3 to cyclopropanol 4, on the other hand methylcyclopropane 1 a is oxidized to cyclopropylmethanol 5, also without ring opening, Eq. (2) [6]. 

Methylococcus capsulatus, diferric iron cluster, 43 362-363 mixed-valent state, 43 389 s derived from reaction mechanism, 43 391-393... 

Methylococcus capsulatus, methane monooxygenase, diferric iron cluster, 43 362-363 2-(l-Methylpyridinium-4-yl)-4,4,5,5,-... 

The multiprotein complex methane monooxygenase (MMO) serves meth-anotrophs to convert methane to methanol. It can be either soluble (sMMO) or membrane bound ( particulate , pMMO) and it typically consists of three components, a reductase (MMOR), a component termed protein B (MMOB) and a hydroxylase denoted MMOH. The nature of the metal cofactors in the latter component are reasonably well understood for sMMO as will be discussed in the non-heme iron section. For the pMMO of Methylococcus capsulatus an obligate requirement for copper was shown. As reported in reference 1 a trinuclear Cu(II) cluster was discussed128 but the number and coordination of coppers still is a matter of continuing investigation since then. 

Flo. 5.46. Maximal growth rate of Methylococcus capsulatus as a function of pH... 

It seems probable that other redox centres contain this binuclear iron structure, but that this has not yet been recognized. For example, a non-heme iron protein of the methane monooxygenase from Methylococcus capsulatus (Bath), which functions as the oxygenase in equation (28), has been described as having a novel iron centre which is not an iron-sulfur cluster. This may well be an oxo-bridged system. Analysis suggests 2.3 Fe per molecule of protein. 

Basu, P. Katterle, B. Andersson, K. K. Dalton, H. The membrane-associated form of methane mono-oxygenase from Methylococcus capsulatus (Bath) is a copper/iron protein. Biochem. J. 2003, 369(2), 417 127. 

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. 

Zahn, J. A. DiSpirito, A. A. Membrane-associated methane monooxygenase from Methylococcus capsulatus (Bath). J. Bacteriol. 1996, 178(4), 1018-1029. 

Martinho, M. Choi, D. W. Dispirito, A. A. Antholine, W. E. Semrau, J. D. Miinck, E. Mossbauer studies of the membrane-associated methane monooxygenase from Methylococcus capsulatus bath evidence for a diiron center. J. Am. Chem. Soc. 2007, 729(51), 15783-15785. 

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. 

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