5FEZ: Hyde From T. Maritima In Complex With (2r,4r)-mesetda, 5'- Deoxyadenosine And Methionine

Citation:
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.
PDB ID: 5FEZDownload
MMDB ID: 138134
PDB Deposition Date: 2015/12/17
Updated in MMDB: 2016/05
Experimental Method:
x-ray diffraction
Resolution: 1.35  Å
Source Organism:
Similar Structures:
Biological Unit for 5FEZ: monomeric; determined by author and by software (PISA)
Molecular Components in 5FEZ
Label Count Molecule
Protein (1 molecule)
1
[fefe] Hydrogenase Maturase Subunit Hyde(Gene symbol: TM1269)
Molecule annotation
Chemicals (10 molecules)
1
1
2
5
3
1
4
1
5
1
6
1
* Click molecule labels to explore molecular sequence information.

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