title: Tetrahydromethanopterin methyltransferase, a component of the methane synthesizing complex of Methanobacterium thermoautotrophicum.
abstract: 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: D019605:Euryarchaeota / Q000201:enzymology*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015080:Mesna / Q000378:metabolism; D008697:Methane / Q000096:biosynthesis*; D008780:Methyltransferases / Q000378:metabolism*; D011622:Pterins / Q000378:metabolism
chemical_list: D011622:Pterins; C042416:5,6,7,8-tetrahydromethanopterin; D008780:Methyltransferases; C048755:tetrahydromethanopterin S-methyltransferase; D015080:Mesna; D008697:Methane