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Publication Abstract from PubMed

[FeFe]-hydrogenases are efficient H(2)-catalysts, yet upon contact with dioxygen their catalytic cofactor (H-cluster) is irreversibly inactivated. Here, we combine X-ray crystallography, rational protein design, direct electrochemistry, and Fourier-transform infrared spectroscopy to describe a protein morphing mechanism that controls the reversible transition between the catalytic H(ox)-state and the inactive but oxygen-resistant H(inact)-state in [FeFe]-hydrogenase CbA5H of Clostridium beijerinckii. The X-ray structure of air-exposed CbA5H reveals that a conserved cysteine residue in the local environment of the active site (H-cluster) directly coordinates the substrate-binding site, providing a safety cap that prevents O(2)-binding and consequently, cofactor degradation. This protection mechanism depends on three non-conserved amino acids situated approximately 13 A away from the H-cluster, demonstrating that the 1st coordination sphere chemistry of the H-cluster can be remote-controlled by distant residues.

A safety cap protects hydrogenase from oxygen attack.,Winkler M, Duan J, Rutz A, Felbek C, Scholtysek L, Lampret O, Jaenecke J, Apfel UP, Gilardi G, Valetti F, Fourmond V, Hofmann E, Leger C, Happe T Nat Commun. 2021 Feb 2;12(1):756. doi: 10.1038/s41467-020-20861-2. PMID:33531463^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.