Tetrahydromethanopterin methyltransferase, a component of the methane synthesizing complex of Methanobacterium thermoautotrophicum

Biochem Biophys Res Commun. 1986 Apr 29;136(2):542-7. doi: 10.1016/0006-291x(86)90474-2.


A new enzyme, tetrahydromethanopterin methyltransferase, which catalyzes the transfer of methyl groups from methyl-tetrahydromethanopterin to 2-mercaptoethane-sulfonate, has been found in the methane synthesizing complex of Methanobacterium thermoautotrophicum. The enzyme is oxygen sensitive and has a well defined pH optimum at pH 6.7. There was no methyl group transfer when the enzyme was heated to 100 degrees for 5 min. The product of the forward reaction, methyl-CoM, was positively identified by TLC and high voltage paper electrophoresis. The demethylation of methyl-CoM, in the absence of methane synthesis, was dependent on the addition of H4MPT which suggests that the enzyme reaction is reversible.

MeSH terms

  • Euryarchaeota / enzymology*
  • Hot Temperature
  • Hydrogen-Ion Concentration
  • Kinetics
  • Mesna / metabolism
  • Methane / biosynthesis*
  • Methyltransferases / metabolism*
  • Pterins / metabolism


  • Pterins
  • 5,6,7,8-tetrahydromethanopterin
  • Methyltransferases
  • tetrahydromethanopterin S-methyltransferase
  • Mesna
  • Methane