The Fe-V cofactor of vanadium nitrogenase contains an interstitial carbon atom

17.09.2015

Rees JA, Bjornsson R, Schlesier J, Sippel D, Einsle O, DeBeer S.

Angew Chem Int Ed Engl. 2015;54(45):13249-52.

Angew Chem Int Ed Engl.            online article

The first direct evidence is provided for the presence of an interstitial carbide in the Fe· V cofactor of Azotobacter vinelandii vanadium nitrogenase. As for our identification of the central carbide in the Fe· Mo cofactor, we employed Fe Kb valence-to-core X-ray emission spectroscopy and density func- tional theory calculations, and herein report the highly similar spectra of both variants of the cofactor-containing protein. The identification of an analogous carbide, and thus an atomically homologous active site in vanadium nitrogenase, highlights the importance and influence of both the interstitial carbide and the identity of the heteroatom on the electronic structure and catalytic activity of the enzyme.