6Q93

MgADP-bound Fe protein of Vanadium nitrogenase from Azotobacter vinelandii

Summary for 6Q93

• Entry DOI: 10.2210/pdb6q93/pdb
• Descriptor: Nitrogenase iron protein, IRON/SULFUR CLUSTER, ADENOSINE-5'-DIPHOSPHATE, ... (5 entities in total)
• Functional Keywords: biological nitrogen fixation, dinitrogenase reductase, vanadium nitrogenase, fe protein, vnfh, electron transport
• Biological source: Azotobacter vinelandii (strain DJ / ATCC BAA-1303)
• Total number of polymer chains: 8
• Total formula weight: 253552.71

Authors

Rohde, M.,Gerhardt, S.,Einsle, O. (deposition date: 2018-12-17, release date: 2019-02-27, Last modification date: 2024-01-24)

Primary citation

Rohde, M.,Trncik, C.,Sippel, D.,Gerhardt, S.,Einsle, O.
Crystal structure of VnfH, the iron protein component of vanadium nitrogenase.
J. Biol. Inorg. Chem., 23:1049-1056, 2018

PubMed Abstract: Nitrogenases catalyze the biological fixation of inert N into bioavailable ammonium. They are bipartite systems consisting of the catalytic dinitrogenase and a complementary reductase, the Fe protein that is also the site where ATP is hydrolyzed to drive the reaction forward. Three different subclasses of dinitrogenases are known, employing either molybdenum, vanadium or only iron at their active site cofactor. Although in all these classes the mode and mechanism of interaction with Fe protein is conserved, each one encodes its own orthologue of the reductase in the corresponding gene cluster. Here we present the 2.2 Å resolution structure of VnfH from Azotobacter vinelandii, the Fe protein of the alternative, vanadium-dependent nitrogenase system, in its ADP-bound state. VnfH adopts the same conformation that was observed for NifH, the Fe protein of molybdenum nitrogenase, in complex with ADP, representing a state of the functional cycle that is ready for reduction and subsequent nucleotide exchange. The overall similarity of NifH and VnfH confirms the experimentally determined cross-reactivity of both ATP-hydrolyzing reductases.

PubMed: 30141094
DOI: 10.1007/s00775-018-1602-4

Experimental method

X-RAY DIFFRACTION (2.2 Å)