6FEA

A. vinelandii vanadium nitrogenase, turnover state

Summary for 6FEA

• Entry DOI: 10.2210/pdb6fea/pdb
• Related: 5N6Y
• Descriptor: Nitrogenase protein alpha chain, MAGNESIUM ION, Vanadium nitrogenase beta subunit, vnfK, ... (11 entities in total)
• Functional Keywords: nitrogen fixation, iron-sulfur-enzymes, vanadium, nitrogenase, metal binding protein
• Biological source: Azotobacter vinelandii DJ; More
• Total number of polymer chains: 6
• Total formula weight: 243913.57

Authors

Sippel, D.,Einsle, O. (deposition date: 2017-12-31, release date: 2018-03-28, Last modification date: 2024-01-17)

Primary citation

Sippel, D.,Rohde, M.,Netzer, J.,Trncik, C.,Gies, J.,Grunau, K.,Djurdjevic, I.,Decamps, L.,Andrade, S.L.A.,Einsle, O.
A bound reaction intermediate sheds light on the mechanism of nitrogenase.
Science, 359:1484-1489, 2018

PubMed Abstract: Reduction of N by nitrogenases occurs at an organometallic iron cofactor that commonly also contains either molybdenum or vanadium. The well-characterized resting state of the cofactor does not bind substrate, so its mode of action remains enigmatic. Carbon monoxide was recently found to replace a bridging sulfide, but the mechanistic relevance was unclear. Here we report the structural analysis of vanadium nitrogenase with a bound intermediate, interpreted as a μ-bridging, protonated nitrogen that implies the site and mode of substrate binding to the cofactor. Binding results in a flip of amino acid glutamine 176, which hydrogen-bonds the ligand and creates a holding position for the displaced sulfide. The intermediate likely represents state E or E of the Thorneley-Lowe model and provides clues to the remainder of the catalytic cycle.

PubMed: 29599235
DOI: 10.1126/science.aar2765

Experimental method

X-RAY DIFFRACTION (1.2 Å)