title: ATP-independent substrate reduction by nitrogenase P-cluster variant.
abstract: The P-cluster of nitrogenase is largely known for its function to mediate electron transfer to the active cofactor site during catalysis. Here, we show that a P-cluster variant (designated P*-cluster), which consists of paired [Fe(4)S(4)]-like clusters, can catalyze ATP-independent substrate reduction in the presence of a strong reductant, europium(II) diethylenetriaminepentaacetate [Eu(II)-DTPA]. The observation of a decrease of activity in the rank ΔnifH, ΔnifBΔnifZ, and ΔnifB MoFe protein, which corresponds to a decrease of the amount of P*-clusters in these cofactor-deficient proteins, firmly establishes P*-cluster as a catalytically active metal center in Eu(II)-DTPA-driven reactions. More excitingly, the fact that P*-cluster is not only capable of catalyzing the two-electron reduction of proton, acetylene, ethylene, and hydrazine, but also capable of reducing cyanide, carbon monoxide, and carbon dioxide to alkanes and alkenes, points to a possibility of developing biomimetic catalysts for hydrocarbon production under ambient conditions.
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, USA.
authors.forename: Chi Chung
authors.initials: CC
authors.lastname: Lee
authors.forename: Yilin
authors.initials: Y
authors.lastname: Hu
authors.forename: Markus W
authors.initials: MW
authors.lastname: Ribbe
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D016948:Azotobacter vinelandii / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D005798:Genes, Bacterial; D014644:Genetic Variation; D007700:Kinetics; D009591:Nitrogenase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; C092498:NifB protein, Bacteria; D000255:Adenosine Triphosphate; D010088:Oxidoreductases; D009591:Nitrogenase; C029130:nitrogenase reductase