Download MendeleyCarbon-sulfur bond-forming reaction catalysed by the radical SAM enzyme HydE.
Rohac, R., Amara, P., Benjdia, A., Martin, L., Ruffie, P., Favier, A., Berteau, O., Mouesca, J.M., Fontecilla-Camps, J.C., Nicolet, Y.(2016) Nat Chem 8: 491-500
- PubMed: 27102684
- DOI: https://doi.org/10.1038/nchem.2490
- Primary Citation of Related Structures:
5FEP, 5FES, 5FEW, 5FEX, 5FEZ, 5FF0, 5FF2, 5FF3, 5FF4 - PubMed Abstract:
Carbon-sulfur bond formation at aliphatic positions is a challenging reaction that is performed efficiently by radical S-adenosyl-L-methionine (SAM) enzymes. Here we report that 1,3-thiazolidines can act as ligands and substrates for the radical SAM enzyme HydE, which is involved in the assembly of the active site of [FeFe]-hydrogenase. Using X-ray crystallography, in vitro assays and NMR spectroscopy we identified a radical-based reaction mechanism that is best described as the formation of a C-centred radical that concomitantly attacks the sulfur atom of a thioether. To the best of our knowledge, this is the first example of a radical SAM enzyme that reacts directly on a sulfur atom instead of abstracting a hydrogen atom. Using theoretical calculations based on our high-resolution structures we followed the evolution of the electronic structure from SAM through to the formation of S-adenosyl-L-cysteine. Our results suggest that, at least in this case, the widely proposed and highly reactive 5'-deoxyadenosyl radical species that triggers the reaction in radical SAM enzymes is not an isolable intermediate.
Organizational Affiliation:
Metalloproteins Unit, Institut de Biologie Structurale, CEA, CNRS, UGA, 71 Avenue des Martyrs, 38044 Grenoble Cedex 9, France.
