Catalysis Sciences & Engineering, Short talk
CE-016

Molybdoenzyme Mediates Carbon-Sulfur Bond Making and Breaking in Ergothioneine Biosynthesis

G. S. Alim1, R. P. Jakob2, S. B. Bolotova1, J. Yang3, M. L. Kirk3, F. P. Seebeck1*
1Department of Chemistry, University of Basel, Mattenstrasse 24a, Basel 4002, Switzerland, 2Biozentrum, University of Basel, Spitalstrasse 41, Basel CH-4056, Switzerland, 3Department of Chemistry and Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131-0001, United States

Molybdoenzymes are proteins of ancient origins with diverse biological functions, utilizing specific cofactors with molybdenum or tungsten at their centers, commonly referred to as molybdopterin (MPT). Most known molybdoenzymes catalyze stereoselective and regioselective oxidation, dehydroxylation, hydration, and the formation and cleavage of C-O and X-O bond through two-electron transfer mechanism, and have seen potential use in organic synthesis.[1] We discovered MPT-dependent ergothioneine synthase (MES) as the first reported instance of molybdoenzyme catalyzing C-S bond formation, thereby adding it to the repertoire of enzymatic C-S bond formation.[2,3] MES from Caldithrix abyssi composed of an N-terminal module related to tungsten-dependent acetylene hydratase and a C-terminal cysteine desulfurase. These two modules cooperate to transfer sulfur from cysteine onto trimethylhistidine. However, the complexity of producing molybdoenzyme constrained the preceding study to in vivo model.

Here, we present our latest efforts to understand the activity of this class of MPT-dependent enzymes in vitro. Our work encompasses production and purification, reconstruction of biocatalytic activity in vitro, and an initial look of the MES structure.

  1. C. (Chip) Le, M. Bae, S. Kiamehr, E. P. Balskus, Annu. Rev. Biochem. 2022, 91, 475–504.
  2. K. L. Dunbar, D. H. Scharf, A. Litomska, C. Hertweck,  Chem. Rev. 2017, 117, 5521–5577.
  3. M. A. Beliaeva, F. P. Seebeck, JACS Au 2022, 2, 2098–2107.