Identification of coenzyme M biosynthetic phosphosulfolactate synthase: a new family of sulfonate-biosynthesizing enzymes.
The hyperthermophilic euryarchaeon Methanococcus jannaschii uses coenzyme M (2-mercaptoethanesulfonic acid) as the terminal methyl carrier in methanogenesis. We describe an enzyme from that organism, (2R)-phospho-3-sulfolactate synthase (ComA), that catalyzes the first step in coenzyme M biosynthesis. ComA catalyzed the stereospecific Michael addition of sulfite to phosphoenolpyruvate over a broad range of temperature and pH conditions. Substrate and product analogs moderately inhibited activity. This enzyme has no significant sequence similarity to previously characterized enzymes; however, its Mg(2+)-dependent enzyme reaction mechanism may be analogous to one proposed for enolase. A diverse group of microbes and plants have homologs of ComA that could have been recruited for sulfolactate or sulfolipid biosyntheses.
Graham
David E
DE
Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0308, USA.
Xu
Huimin
H
White
Robert H
RH
D000595:Amino Acid Sequence; D013437:Carbon-Sulfur Lyases / Q000096:biosynthesis / Q000737:chemistry* / Q000145:classification*; D002384:Catalysis; D002412:Cations; D003001:Cloning, Molecular; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D016013:Likelihood Functions; D008274:Magnesium / Q000378:metabolism; D015080:Mesna / Q000378:metabolism*; D017014:Methanobacterium / Q000201:enzymology; D017017:Methanococcus / Q000201:enzymology; D008956:Models, Chemical; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013447:Sulfites; D013696:Temperature; D013997:Time Factors
D002412:Cations; D011994:Recombinant Proteins; D013447:Sulfites; C455619:(2R)-phospho-3-sulfolactate synthase; D013437:Carbon-Sulfur Lyases; D008274:Magnesium; D015080:Mesna