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The energy conserving methyltetrahydromethanopterin:coenzyme M methyltransferase complex from methanogenic archaea: function of the subunit MtrH
Author(s) -
Hippler Birgit,
Thauer Rudolf K
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00429-9
Subject(s) - archaea , protein subunit , methyltransferase , methylation , biochemistry , cofactor , chemistry , corrinoid , transferase , enzyme , escherichia coli , stereochemistry , active site , biology , dna , gene
In methanogenic archaea the transfer of the methyl group of N 5 ‐methyltetrahydromethanopterin to coenzyme M is coupled with energy conservation. The reaction is catalyzed by a membrane associated multienzyme complex composed of eight different subunits MtrA–H. The 23 kDa subunit MtrA harbors a corrinoid prosthetic group which is methylated and demethylated in the catalytic cycle. We report here that the 34 kDa subunit MtrH catalyzes the methylation reaction. MtrH was purified and shown to exhibit methyltetrahydromethanopterin:cob(I)alamin methyltransferase activity. Sequence comparison revealed similarity of MtrH with MetH from Escherichia coli and AcsE from Clostridium thermoaceticum : both enzymes exhibit methyltetrahydrofolate:cob(I)alamin methyltransferase activity.