Coenzyme M biosynthesis in bacteria involves phosphate elimination by a functionally distinct member of the aspartase/fumarase superfamily

Abstract

For nearly 30 years, coenzyme M (CoM) was assumed to be present solely in methanogenic archaea. In the late 1990s, CoM was reported to play a role in bacterial propene metabolism, but no biosynthetic pathway for CoM has yet been identified in bacteria. Here, using bioinformatics and proteomic approaches in the metabolically versatile bacterium Py2, we identified four putative CoM biosynthetic enzymes encoded by the, ,, and genes. Only XcbB1 was homologous to a known CoM biosynthetic enzyme (ComA), indicating that CoM biosynthesis in bacteria involves enzymes different from those in archaea. We verified that the ComA homolog produces phosphosulfolactate from phosphoenolpyruvate (PEP), demonstrating that bacterial CoM biosynthesis is initiated similarly as the phosphoenolpyruvate-dependent methanogenic archaeal pathway. The bioinformatics analysis revealed that XcbC1 and D1 are members of the aspartase/fumarase superfamily (AFS) and that XcbE1 is a pyridoxal 5'-phosphate-containing enzyme with homology to d-cysteine desulfhydrases. Known AFS members catalyze β-elimination reactions of succinyl-containing substrates, yielding fumarate as the common unsaturated elimination product. Unexpectedly, we found that XcbC1 catalyzes β-elimination on phosphosulfolactate, yielding inorganic phosphate and a novel metabolite, sulfoacrylic acid. Phosphate-releasing β-elimination reactions are unprecedented among the AFS, indicating that XcbC1 is an unusual phosphatase. Direct demonstration of phosphosulfolactate synthase activity for XcbB1 and phosphate β-elimination activity for XcbC1 strengthened their hypothetical assignment to a CoM biosynthetic pathway and suggested functions also for XcbD1 and E1. Our results represent a critical first step toward elucidating the CoM pathway in bacteria.

Genomic characterization of three novel Desulfobacterota classes expand the metabolic and phylogenetic diversity of the Phylum

“…CoM was shown in the bacterial genera Xanthobacter, Rhodococcus, and Mycobacterium to be involved in propylene degradation as a carrier for a C3 carbon intermediate (58–60). Recently, the bacterial CoM biosynthetic cluster was identified in X. autotrophicus Py2 (61). The genes xcbB1 , C1 , D1 , and E1 encode the bacterial CoM biosynthetic operon, with only xcbB1 showing homology to the archaeal CoM biosynthesis gene comA (61).…”

“…Recently, the bacterial CoM biosynthetic cluster was identified in X. autotrophicus Py2 (61). The genes xcbB1 , C1 , D1 , and E1 encode the bacterial CoM biosynthetic operon, with only xcbB1 showing homology to the archaeal CoM biosynthesis gene comA (61). The remainder of the genes xcbC1 , D1 , and E1 are distinct from the archaeal genes comBCDE , and the bacterial biosynthetic pathway proceeds via a different route (61, 62).…”

“…The genes xcbB1 , C1 , D1 , and E1 encode the bacterial CoM biosynthetic operon, with only xcbB1 showing homology to the archaeal CoM biosynthesis gene comA (61). The remainder of the genes xcbC1 , D1 , and E1 are distinct from the archaeal genes comBCDE , and the bacterial biosynthetic pathway proceeds via a different route (61, 62). CoM biosynthesis genes identified in Class “Anaeropigmentia” genomes are distinct from the bacterial CoM biosynthesis genes xcbC1 , D1 , and E1 and are indeed archaeal-like.…”

Evaluation of Anti-inflammatory, Analgesic, and Antipyretic Activities of Pseuderanthemum palatiferum

“…Transudate has a low protein concentration and consists primarily of lymphocytes, macrophages, and mesothelial cells (Sireeratawong et al, 2013). Prednisolone significantly reduced transudative, granuloma weights and ALP activity (Partovi et al, 2018), whereas, WEPP and ibuprofen did not show any effects on these parameters. Moreover, prednisolone reduced thymus weight and body weight gain.…”

The coenzyme/protein pair and the molecular evolution of life

“…4). 33 The PEP-dependent pathway is initiated by a Michael addition of sulte. This step is followed by phosphate hydrolysis and oxidation to the a-keto acid 30.…”