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Vanadium nitrogenase VFe protein, high CO stateVanadium nitrogenase VFe protein, high CO state
Structural highlights
FunctionVNFD_AZOVI This vanadium-iron protein is part of the nitrogenase complex that catalyzes the key enzymatic reactions in nitrogen fixation. Publication Abstract from PubMedBesides its role in biological nitrogen fixation, vanadium-containing nitrogenase also reduces carbon monoxide (CO) to hydrocarbons, in analogy to the industrial Fischer-Tropsch process. The protein yields 93% of ethylene (C(2)H(4)), implying a C-C coupling step that mandates the simultaneous binding of two CO at the active site FeV cofactor. Spectroscopic data indicated multiple CO binding events, but structural analyses of Mo and V nitrogenase only confirmed a single site. Here, we report the structure of a two CO-bound state of V nitrogenase at 1.05 A resolution, with one mu-bridging and one terminal CO molecule. This additional, specific ligand binding site suggests a mechanistic route for CO reduction and hydrocarbon formation, as well as a second access pathway for protons required during the reaction. Moreover, carbonyls are strong-field ligands that are chemically similar to mechanistically relevant hydrides that may be formed and used in a fully analogous fashion. Two ligand-binding sites in CO-reducing V nitrogenase reveal a general mechanistic principle.,Rohde M, Laun K, Zebger I, Stripp ST, Einsle O Sci Adv. 2021 May 28;7(22):eabg4474. doi: 10.1126/sciadv.abg4474. Print 2021 May. PMID:34049880[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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