Literature summary extracted from
Sauer, K.; Thauer, R.K.
Methyl-coenzyme M formation in methanogenic archaea. Involvement of zinc in coenzyme M activation (2000), Eur. J. Biochem., 267, 2498-2504.
Cloned(Commentary)
EC Number |
Cloned (Comment) |
Organism |
---|
2.1.1.246 |
overexpression of His-tagged inactive MtaA apoprotein in Escherichia coli strain M15 grown in the presence of 2 mM EDTA |
Methanosarcina barkeri |
Inhibitors
EC Number |
Inhibitors |
Comment |
Organism |
Structure |
---|
2.1.1.246 |
EDTA |
75% inhibition at 1 mM, complete inhibition at 2 mM, reversible by Zn2+ addition, competitive versus Zn2+, kinetics, overview |
Methanosarcina barkeri |
|
2.1.1.246 |
additional information |
1 mm nitrilotriacetic acid has almost no effect on the MtaA activity |
Methanosarcina barkeri |
|
Metals/Ions
EC Number |
Metals/Ions |
Comment |
Organism |
Structure |
---|
2.1.1.246 |
Co2+ |
required, the apoprotein reacts with zinc or cobalt to the fully active holoenzyme |
Methanosarcina barkeri |
|
2.1.1.246 |
additional information |
Zn21 or Co21 are required for MtaA activity, Zn2+ can be replaced by Co2+ but not by Mg2+, the kinetics of activation by Co2+ being similarily slow. About 1 mol of transition metal is bound per mol of protein. The role of the transition metal in MtaA is to lower the microscopic pKa of the thiol group of coenzyme M by coordination to the zinc, and thus to increase its nucleophilicity for methyl group attack, pKZn2+ of MtaA is over 15 |
Methanosarcina barkeri |
|
2.1.1.246 |
Zn2+ |
1 mol per mol of enzyme, required, the apoprotein reacts with zinc or cobalt to the fully active holoenzyme |
Methanosarcina barkeri |
|
Molecular Weight [Da]
EC Number |
Molecular Weight [Da] |
Molecular Weight Maximum [Da] |
Comment |
Organism |
---|
2.1.1.246 |
50000 |
- |
x * 50000 |
Methanosarcina barkeri |
Natural Substrates/ Products (Substrates)
EC Number |
Natural Substrates |
Organism |
Comment (Nat. Sub.) |
Natural Products |
Comment (Nat. Pro.) |
Rev. |
Reac. |
---|
2.1.1.246 |
a [methyl-Co(III) methanol-specific corrinoid protein] + coenzyme M |
Methanosarcina barkeri |
- |
methyl-CoM + a [Co(I) methanol-specific corrinoid protein] |
- |
? |
|
Organism
EC Number |
Organism |
UniProt |
Comment |
Textmining |
---|
2.1.1.246 |
Methanosarcina barkeri |
- |
gene mtaA |
- |
Purification (Commentary)
EC Number |
Purification (Comment) |
Organism |
---|
2.1.1.246 |
recombinant His-tagged apo MtaA from Escherichia coli strain M15 by nickel affinity and anionexchange chromatography |
Methanosarcina barkeri |
Reaction
EC Number |
Reaction |
Comment |
Organism |
Reaction ID |
---|
2.1.1.246 |
a [methyl-Co(III) methanol-specific corrinoid protein] + CoM = methyl-CoM + a [Co(I) methanol-specific corrinoid protein] |
coenzyme M binds with its thiol group to the zinc in the active site of MtaA forming a coenzyme M thiolate zinc complex |
Methanosarcina barkeri |
|
Specific Activity [micromol/min/mg]
EC Number |
Specific Activity Minimum [µmol/min/mg] |
Specific Activity Maximum [µmol/min/mg] |
Comment |
Organism |
---|
2.1.1.246 |
2 |
- |
purified Zn2+-containing holoenzyme, pH 7.0, 37°C |
Methanosarcina barkeri |
Substrates and Products (Substrate)
EC Number |
Substrates |
Comment Substrates |
Organism |
Products |
Comment (Products) |
Rev. |
Reac. |
---|
2.1.1.246 |
a [methyl-Co(III) methanol-specific corrinoid protein] + coenzyme M |
- |
Methanosarcina barkeri |
methyl-CoM + a [Co(I) methanol-specific corrinoid protein] |
- |
? |
|
Subunits
EC Number |
Subunits |
Comment |
Organism |
---|
2.1.1.246 |
? |
x * 50000 |
Methanosarcina barkeri |
Synonyms
EC Number |
Synonyms |
Comment |
Organism |
---|
2.1.1.246 |
mtaA |
- |
Methanosarcina barkeri |
Temperature Optimum [°C]
EC Number |
Temperature Optimum [°C] |
Temperature Optimum Maximum [°C] |
Comment |
Organism |
---|
2.1.1.246 |
37 |
- |
assay at |
Methanosarcina barkeri |
pH Optimum
EC Number |
pH Optimum Minimum |
pH Optimum Maximum |
Comment |
Organism |
---|
2.1.1.246 |
7 |
- |
assay at |
Methanosarcina barkeri |
General Information
EC Number |
General Information |
Comment |
Organism |
---|
2.1.1.246 |
additional information |
MtaC and MtaB form a tight complex and the encoding genes form a transcription unit, whereas MtaA purifies separately and its encoding gene is located separately |
Methanosarcina barkeri |
2.1.1.246 |
physiological function |
the methyltransferase designated MtaA together with the proteins MtaB and MtaC mediate the formation of methyl-coenzyme M from methanol and coenzyme M. MtaC is a 28-kDa corrinoid protein, MtaB, EC 2.1.1.90, catalyzes the methylation of MtaC and MtaA catalyzes the demethylation of methylated MtaC |
Methanosarcina barkeri |