9cu1

Structural highlights

Function

FESII_AZOVI Binds to and protects nitrogenase from irreversible exposure to O(2), in what is known as 'conformational protection' (PubMed:10220344, PubMed:26654855, PubMed:7548055, PubMed:7830548). Shifts nitrogenase into an inactive, O(2)-tolerant state. Exists in 2 states, an open oxidized state that binds and protects nitrogenase, and a closed reduced state that probably does not bind nitrogenase; cooperative oxidation of the 2Fe-2S clusters causes the conformation change (PubMed:26654855). Does not protect nitrogenase with the vanadium-iron subunit, not clear if it protects the iron-only nitrogenase (PubMed:7830548).^{[1] [2] [3] [4]}

References

1. ↑ Lou J, Moshiri F, Johnson MK, Lafferty ME, Sorkin DL, Miller A, Maier RJ. Mutagenesis studies of the FeSII protein of Azotobacter vinelandii: roles of histidine and lysine residues in the protection of nitrogenase from oxygen damage. Biochemistry. 1999 Apr 27;38(17):5563-71. PMID:10220344 doi:10.1021/bi9827823
2. ↑ Schlesier J, Rohde M, Gerhardt S, Einsle O. A Conformational Switch Triggers Nitrogenase Protection from Oxygen Damage by Shethna Protein II (FeSII). J Am Chem Soc. 2015 Dec 24. PMID:26654855 doi:http://dx.doi.org/10.1021/jacs.5b10341
3. ↑ Moshiri F, Crouse BR, Johnson MK, Maier RJ. The "nitrogenase-protective" FeSII protein of Azotobacter vinelandii: overexpression, characterization, and crystallization. Biochemistry. 1995 Oct 10;34(40):12973-82. PMID:7548055 doi:10.1021/bi00040a007
4. ↑ Moshiri F, Kim JW, Fu C, Maier RJ. The FeSII protein of Azotobacter vinelandii is not essential for aerobic nitrogen fixation, but confers significant protection to oxygen-mediated inactivation of nitrogenase in vitro and in vivo. Mol Microbiol. 1994 Oct;14(1):101-14. PMID:7830548 doi:10.1111/j.1365-2958.1994.tb01270.x