6O0B

Structural and Mechanistic Insights into CO2 Activation by Nitrogenase Iron Protein

Summary for 6O0B

• Entry DOI: 10.2210/pdb6o0b/pdb
• Descriptor: Nitrogenase iron protein, IRON/SULFUR CLUSTER (3 entities in total)
• Functional Keywords: nitrogenase, iron protein, iron-sulfur cluster, oxidoreductase
• Biological source: Azotobacter vinelandii (strain DJ / ATCC BAA-1303)
• Total number of polymer chains: 2
• Total formula weight: 63185.73

Authors

Rettberg, L.A.,Stiebritz, M.T.,Kang, W.,Lee, C.C.,Ribbe, M.W.,Hu, Y. (deposition date: 2019-02-15, release date: 2019-09-04, Last modification date: 2023-10-11)

Primary citation

Rettberg, L.A.,Stiebritz, M.T.,Kang, W.,Lee, C.C.,Ribbe, M.W.,Hu, Y.
Structural and Mechanistic Insights into CO2Activation by Nitrogenase Iron Protein.
Chemistry, 25:13078-13082, 2019

PubMed Abstract: The Fe protein of nitrogenase catalyzes the ambient reduction of CO when its cluster is present in the all-ferrous, [Fe S ] oxidation state. Here, we report a combined structural and theoretical study that probes the unique reactivity of the all-ferrous Fe protein toward CO . Structural comparisons of the Azotobacter vinelandii Fe protein in the [Fe S ] and [Fe S ] states point to a possible asymmetric functionality of a highly conserved Arg pair in CO binding and reduction. Density functional theory (DFT) calculations provide further support for the asymmetric coordination of O by the "proximal" Arg and binding of C to a unique Fe atom of the all-ferrous cluster, followed by donation of protons by the proximate guanidinium group of Arg that eventually results in the scission of a C-O bond. These results provide important mechanistic and structural insights into CO activation by a surface-exposed, scaffold-held [Fe S ] cluster.

PubMed: 31402524
DOI: 10.1002/chem.201903387

Experimental method

X-RAY DIFFRACTION (1.6 Å)