In methanobacteria (2R)-phospho-3-sulfolactate synthase (ComA) catalyzes the first step of the biosynthesis of coenzyme M from phosphoenolpyruvate (P-enolpyruvate). This novel enzyme catalyzes the stereospecific Michael addition of sulfite to P-enolpyruvate, forming L-2-phospho-3-sulfolactate (PSL). It is suggested that the ComA-catalyzed reaction is analogous to those reactions catalyzed by beta-elimination enzymes that proceed through an enolate intermediate.
Lu S et al.(2020). "CDD/SPARCLE: the conserved domain database in 2020.",