Cloned (Comment) | Organism |
---|---|
gene mtsA, functional expression in Escherichia coli strain BL21(DE3)pLysS, MtsA is expressed largely in an insoluble form | Methanosarcina barkeri |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Dimethylsulfide | inhibits methylcobalamin:coenzyme methyl transfer by MtsA. Inhibition by dimethylsulfide is mixed with respect to methylcobalamin, but competitive with coenzyme M | Methanosarcina barkeri |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | kinetic analysis, overview | Methanosarcina barkeri | |
5.5 | - |
a [Co(I) methylated-thiol-specific corrinoid protein] | recombinant enzyme, pH 7.0, 37°C | Methanosarcina barkeri | |
10.8 | - |
coenzyme M | recombinant enzyme, pH 7.0, 37°C | Methanosarcina barkeri | |
33 | - |
Dimethylsulfide | recombinant enzyme, pH 7.0, 37°C | Methanosarcina barkeri |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Zn2+ | one zinc atom per polypeptide | Methanosarcina barkeri |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
41000 | - |
2 * 41000, recombinant enzyme, SDS-PAGE | Methanosarcina barkeri |
77000 | - |
recombinant enzyme, gel filtration | Methanosarcina barkeri |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
dimethylsulfide + coenzyme M | Methanosarcina barkeri | - |
methyl-CoM + methanethiol | - |
? | |
methanethiol + coenzyme M | Methanosarcina barkeri | - |
methyl-CoM + hydrogen sulfide | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Methanosarcina barkeri | - |
- |
- |
Purification (Comment) | Organism |
---|---|
recombinant MtsA solubilized from inclusion bodies after expression in Escherichia coli strain BL21(DE3) | Methanosarcina barkeri |
Renatured (Comment) | Organism |
---|---|
recombinant enzyme from inclusion bodies harvested from cells solubilized using 6 M guanidine hydrochloride, 50 mM DTT, and 20 mM 2-mercaptoethanol. The solubilized protein is diluted 60fold with protein refolding at room temperature for 24 h in refolding buffer consisting of 500 mM Tris, pH 8.0, 1 M KCl, 10 mM DTT, 10 mM 2-mercaptoethanol, and 100 mM ZnCl2. Refolding buffers containing 500 mM guanidine hydrochloride, 33 mM CHAPS, 0.5% Triton X-100, 5 mM SDS, or 20% glycerol do not produce active methyltransferase, nor do refolding at 4°C in the optimal refolding buffer | Methanosarcina barkeri |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.078 | - |
purified recombinant enzyme, substrate is dimethylsulfide, pH 7.0, 37°C | Methanosarcina barkeri |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
a [methyl-Co(III) methylated-thiol-specific corrinoid protein] + coenzyme M | - |
Methanosarcina barkeri | methyl-CoM + a [Co(I) methylated-thiol-specific corrinoid protein] | - |
? | |
dimethylsulfide + coenzyme M | - |
Methanosarcina barkeri | methyl-CoM + methanethiol | - |
? | |
methanethiol + a [Co(I) methylated-thiol-specific corrinoid protein] | - |
Methanosarcina barkeri | a [methyl-Co(III) methylated-thiol-specific corrinoid protein] + hydrogen sulfide | - |
? | |
methanethiol + coenzyme M | - |
Methanosarcina barkeri | methyl-CoM + hydrogen sulfide | - |
? | |
additional information | MtsA acts both to demethylate dimethylsulfide and to methylate CoM using non-protein-bound cobalamin as an intermediate methyl carrier, dependence of the rate of the MtsA-catalyzed methylcobalamin:CoM methyl transfer reaction on methylcobalamin, overview. The subunit carries out both CoM methylation and DMS demethylation and can account for both corrinoid-dependent methyltransferase activities of the methylthiol:CoM methyltransferase. A model for the native methylthiol:coenzyme M methyltransferase in which MtsA mediates the methylation of corrinoid bound to MtsB with dimethylsulfide and subsequently demethylates MtsB-bound corrinoid with coenzyme M, overview | Methanosarcina barkeri | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
homodimer | 2 * 41000, recombinant enzyme, SDS-PAGE | Methanosarcina barkeri |
Synonyms | Comment | Organism |
---|---|---|
methylthiol:coenzyme M methyltransferase | - |
Methanosarcina barkeri |
MtsA | - |
Methanosarcina barkeri |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
22 | - |
Cob(I)alamin methylation assay at | Methanosarcina barkeri |
37 | - |
methylcobalamin:CoM methyltransferase activity assay at | Methanosarcina barkeri |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Methanosarcina barkeri |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
additional information | no corrinoid cofactor bound to the enzyme | Methanosarcina barkeri |
General Information | Comment | Organism |
---|---|---|
physiological function | methanogenesis from dimethylsulfide requires the intermediate methylation of coenzyme M. This reaction is catalyzed by a methylthiol:coenzymeMmethyltransferase composed of two polypeptides, MtsA, which is a methylcobalamin:coenzyme M methyltransferase, and MtsB, which is homologous to a class of corrinoid proteins involved in methanogenesis. MtsA is an active methylcobalamin:coenzyme M methyltransferase, but also methylates cob(I)alamin with dimethylsulfide, yielding equimolar methylcobalamin and methanethiol | Methanosarcina barkeri |