KEGG   ENZYME: 2.1.1.251Help
Entry
EC 2.1.1.251                Enzyme                                 

Name
methylated-thiol---coenzyme M methyltransferase;
mtsA (gene name)
Class
Transferases;
Transferring one-carbon groups;
Methyltransferases
BRITE hierarchy
Sysname
methylated-thiol:CoM methyltransferase
Reaction(IUBMB)
methanethiol + CoM = methyl-CoM + hydrogen sulfide (overall reaction) [RN:R09997];
(1a) methanethiol + a [Co(I) methylated-thiol-specific corrinoid protein] = a [methyl-Co(III) methylated-thiol-specific corrinoid protein] + hydrogen sulfide [RN:R10001];
(1b) a [methyl-Co(III) methylated-thiol-specific corrinoid protein] + CoM = methyl-CoM + a [Co(I) methylated-thiol-specific corrinoid protein] [RN:R10000]
Reaction(KEGG)
Substrate
methanethiol [CPD:C00409];
CoM [CPD:C03576];
[Co(I) methylated-thiol-specific corrinoid protein];
[methyl-Co(III) methylated-thiol-specific corrinoid protein]
Product
methyl-CoM [CPD:C03920];
hydrogen sulfide [CPD:C00283];
[methyl-Co(III) methylated-thiol-specific corrinoid protein];
[Co(I) methylated-thiol-specific corrinoid protein]
Comment
The enzyme, which is involved in methanogenesis from methylated thiols, such as methane thiol, dimethyl sulfide, and 3-S-methylmercaptopropionate, catalyses two successive steps - the transfer of a methyl group from the substrate to the cobalt cofactor of a methylated-thiol-specific corrinoid protein (MtsB), and the subsequent transfer of the methyl group from the corrinoid protein to CoM. With most other methanogenesis substrates this process is carried out by two different enzymes (for example, EC 2.1.1.90, methanol---corrinoid protein Co-methyltransferase, and EC 2.1.1.246, methylated methanol-specific corrinoid protein:coenzyme M methyltransferase). The cobalt is oxidized during methylation from the Co(I) state to the Co(III) state, and is reduced back to the Co(I) form during demethylation.
History
EC 2.1.1.251 created 2012
Pathway
ec00920  Sulfur metabolism
Orthology
K16954  methylthiol:coenzyme M methyltransferase
Genes
MBA: Mbar_A3585
MBY: MSBRM_1542
MBW: MSBRW_1148
MBAR: MSBR2_0865
MBAK: MSBR3_1223
MMA: MM_2427(mtsA)
MMAZ: MmTuc01_2485
MMJ: MSMAS_2273
MMAC: MSMAC_2181
MVC: MSVAZ_1681
MARC: AR505_1066
 » show all
Taxonomy
Reference
1  [PMID:8932317]
  Authors
Paul L, Krzycki JA
  Title
Sequence and transcript analysis of a novel Methanosarcina barkeri methyltransferase II homolog and its associated corrinoid protein homologous to methionine synthase.
  Journal
J. Bacteriol. 178 (1996) 6599-607.
  Sequence
Reference
2  [PMID:9371433]
  Authors
Tallant TC, Krzycki JA
  Title
Methylthiol:coenzyme M methyltransferase from Methanosarcina barkeri, an enzyme of methanogenesis from dimethylsulfide and methylmercaptopropionate.
  Journal
J. Bacteriol. 179 (1997) 6902-11.
  Sequence
Reference
3  [PMID:11073950]
  Authors
Tallant TC, Paul L, Krzycki JA
  Title
The MtsA subunit of the methylthiol:coenzyme M methyltransferase of Methanosarcina barkeri catalyses both half-reactions of corrinoid-dependent dimethylsulfide: coenzyme M methyl transfer.
  Journal
J. Biol. Chem. 276 (2001) 4485-93.
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 2.1.1.251
IUBMB Enzyme Nomenclature: 2.1.1.251
ExPASy - ENZYME nomenclature database: 2.1.1.251
BRENDA, the Enzyme Database: 2.1.1.251

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