4tkv

CO-bound Nitrogenase MoFe-protein from A. vinelandii

spinqualitylabelsall models 4tkv, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4tkv is a 4 chain structure with sequence from Azotobacter vinelandii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CLF, CMO, FE2, HCA, ICE, IMD Related: 1m1n, 3u7q, 4tku Activity: Nitrogenase, with EC number 1.18.6.1 Resources: FirstGlance, OCA, RCSB, PDBsum Function [NIFD_AZOVI] This molybdenum-iron protein is part of the nitrogenase complex that catalyzes the key enzymatic reactions in nitrogen fixation. [NIFK_AZOVI] This molybdenum-iron protein is part of the nitrogenase complex that catalyzes the key enzymatic reactions in nitrogen fixation. Publication Abstract from PubMed The mechanism of nitrogenase remains enigmatic, with a major unresolved issue concerning how inhibitors and substrates bind to the active site. We report a crystal structure of carbon monoxide (CO)-inhibited nitrogenase molybdenum-iron (MoFe)-protein at 1.50 angstrom resolution, which reveals a CO molecule bridging Fe2 and Fe6 of the FeMo-cofactor. The mu2 binding geometry is achieved by replacing a belt-sulfur atom (S2B) and highlights the generation of a reactive iron species uncovered by the displacement of sulfur. The CO inhibition is fully reversible as established by regain of enzyme activity and reappearance of S2B in the 1.43 angstrom resolution structure of the reactivated enzyme. The substantial and reversible reorganization of the FeMo-cofactor accompanying CO binding was unanticipated and provides insights into a catalytically competent state of nitrogenase. Ligand binding to the FeMo-cofactor: structures of CO-bound and reactivated nitrogenase.,Spatzal T, Perez KA, Einsle O, Howard JB, Rees DC Science. 2014 Sep 26;345(6204):1620-3. doi: 10.1126/science.1256679. PMID:25258081 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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