EC Number   |
Natural Substrates |
|---|
   2.1.1.90 | methanol + a [Co(I) methanol-specific corrinoid protein] |
- |
| 2.1.1.90 | methanol + cob(I)alamin |
- |
| 2.1.1.90 | more |
analysis of mtaCB gene regulation in Methanosarcina acetivorans |
| 2.1.1.90 | methanol + a [Co(I) methanol-specific corrinoid protein] |
first of two enzymes involved in the transmethylation reaction from methanol to 2-mercaptoethanesulfonic acid in. The enzyme only binds the methyl group of methanol when the cobalt atom of its corrinoid prosthetic groups is present in the highly reduced Co(I) state. Formation of this redox state requires H2, hydrogenase, methyltransferase activation protein, and ATP. Purified enzyme contains 1.7 corrinoids per enzyme with cobalt in the fully oxidized Co(III) state. Water and N-3 of the 5-hydroxybenzimidazolyl base serve as the upper and lower ligands, respectively. Reduction to the Co(II) level is accomplished by H2 and hydrogenase. The cob(II)amide of the enzyme has the base coordinated at this stage. Subsequent addition of methyltransferase activation protein and ATP results in the formation of base-uncoordinated Co(II) enzyme |
| 2.1.1.90 | methanol + 5-hydroxybenzimidazolylcobamide |
methanol catabolism in Methanosarcina species requires the concerted effort of methanol:5-hydroxybenzimidazolylcobamide methyltransferase (MtaB), a corrinoid-containing methyl-accepting protein (MtaC) and Co-methyl-5-hydroxybenzimidazolylcobamide:2-mercapto-ethanesulfonic acid methyltransferase (MtaA). Methanosarcina acetivorans possesses three operons encoding putative methanol-specific MtaB and corrinoid proteins: mtaCB1, mtaCB2 and mtaCB3. Deletion mutants lacking the three operons, in all possible combinations, are constructed and characterized. Strains deleted for any two of the operons grow on methanol, whereas strains lacking all three do not |
| 2.1.1.90 | methanol + cob(I)alamin |
methylation of free cob(I)alamin by methylmercaptopropionate, which is the physiologically relevant direction, is observed only in the presence of very high levels of methylmercaptopropionate |
| 2.1.1.90 | methanol + 5-hydroxybenzimidazolylcobamide |
one of the enzymes responsible for the transmethylation from methanol to coenzyme M |
