Methane monooxygenase
| Methane monooxygenase ( Methylococcus capsulatus ) | ||
|---|---|---|
| Mass / length primary structure | 1677 = (527 + 388 + 170) + 141 + 348 + 103 amino acids | |
| Secondary to quaternary structure | Heterohexamer A (α + β + γ) + B + C + D |
|
| Cofactor | Aα: Fe C: (2Fe + 2S), FAD |
|
| Identifier | ||
| Gene name (s) | mmoX + Y + Z + mmoB + mmoC + mmoD | |
| Enzyme classification | ||
| EC, category | 1.14.13.25 , monooxygenase | |
| Response type | Addition of an oxygen atom | |
| Substrate | Methane + NAD (P) H + O 2 | |
| Products | Methanol + NAD (P) + + H 2 O | |
| Occurrence | ||
| Parent taxon | Methanotrophic bacteria | |
The methane monooxygenase is a multi- protein complex with a molecular mass of 300 kDa . It catalyzes the oxidation of the inert methane to methanol in methanotrophic bacteria , where it is the only source of carbon and energy. The enzyme from Methylococcus capsulatus has been extensively investigated as a model .
Methane monooxygenase consists of four subunits called A, B, C, D, with A itself being made up of three further units α, β and γ. The names are mmoX / Y / Z (for A) and mmoB, mmoC, mmoD.
In the active center of hydroxylase, methane oxidation is carried out with the help of a dinuclear iron center . The iron atoms are coordinated by six amino acid residues . This means that this enzyme belongs to the class of non-heme iron enzymes .
literature
- JC Murrell, ME Lidstrom, AJ Holmes, A. Costello: Evidence that particulate methane monooxygenase and ammonia monooxygenase may be evolutionarily related. In: FEMS Microbiol. Lett. 132 (3), 1995, pp. 203-208. doi: 10.1111 / j.1574-6968.1995.tb07834.x . PMID 7590173 .
- LA Sayavedra-soto, NG Hommes, DJ Arp: Molecular biology and biochemistry of ammonia oxidation by Nitrosomonas europaea. In: Arch. Microbiol. 178 (4), 2002, pp. 250-255. doi: 10.1007 / s00203-002-0452-0 . PMID 12209257 .
- RL Lieberman, AC Rosenzweig: Crystal structure of a membrane-bound metalloenzyme that catalyses the biological oxidation of methane. In: Nature. 434 (7030), 2005, pp. 177-182. doi: 10.1038 / nature03311 . PMID 15674245 .
- AC Rosenzweig, CA Frederick, SJ Lippard, P. Nordlund: Crystal structure of bacterial non-haem iron hydroxylase that catalyses the biological oxidation of methane. In: Nature. 366 (6455), 1993, pp. 537-543. doi: 10.1038 / 366537a0 . PMID 8255292 .
- Harold Basch et al: Mechanism of the Methane -> Methanol Conversion Reaction Catalyzed by Methane Monooxygenase: A Density Function Study. In: J. Am. Chem. Soc. 121 (31), 1999, pp. 7249-7256. doi: 10.1021 / ja9906296 .
- P. Nordlund, BM Sjöberg, H. Eklund: Three-dimensional structure of the free radical protein of ribonucleotide reductase. In: Nature. 345 (6276), 1990, pp. 593-598. doi: 10.1038 / 345593a0 . PMID 2190093 .
- P. Nordlund, H. Eklund: Structure and function of the Escherichia coli ribonucleotide reductase protein R2. In: J. Mol. Biol. 232 (1), 1993, pp. 123-164. doi: 10.1006 / jmbi.1993.1374 . PMID 8331655 .
- K. Liu et al: Characterization of a Diiron (III) Peroxide Intermediate in the Reaction Cycle of Methane Monooxygenase Hydroxylase from Methylococcus capsulatus (Bath). In: J. Am. Chem. Soc. 117, 1995, p. 4997. doi: 10.1021 / ja00122a032 .