8ENN

Homocitrate-deficient nitrogenase MoFe-protein from Azotobacter vinelandii nifV knockout

8ENN の概要

• エントリーDOI: 10.2210/pdb8enn/pdb
• EMDBエントリー: 28272 28273 28274 28275
• 分子名称: Nitrogenase molybdenum-iron protein alpha chain, Nitrogenase molybdenum-iron protein beta chain, iron-sulfur-molybdenum cluster with interstitial carbon, ... (8 entities in total)
• 機能のキーワード: nitrogenase, nitrogen fixation, reductase, mofe, oxidoreductase
• 由来する生物種: Azotobacter vinelandii DJ; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 231295.40

構造登録者

Warmack, R.A.,Maggiolo, A.O.,Rees, D.C. (登録日: 2022-09-30, 公開日: 2023-03-08, 最終更新日: 2024-06-19)

主引用文献

Warmack, R.A.,Maggiolo, A.O.,Orta, A.,Wenke, B.B.,Howard, J.B.,Rees, D.C.
Structural consequences of turnover-induced homocitrate loss in nitrogenase.
Nat Commun, 14:1091-1091, 2023

PubMed Abstract: Nitrogenase catalyzes the ATP-dependent reduction of dinitrogen to ammonia during the process of biological nitrogen fixation that is essential for sustaining life. The active site FeMo-cofactor contains a [7Fe:1Mo:9S:1C] metallocluster coordinated with an R-homocitrate (HCA) molecule. Here, we establish through single particle cryoEM and chemical analysis of two forms of the Azotobacter vinelandii MoFe-protein - a high pH turnover inactivated species and a ∆NifV variant that cannot synthesize HCA - that loss of HCA is coupled to α-subunit domain and FeMo-cofactor disordering, and formation of a histidine coordination site. We further find a population of the ∆NifV variant complexed to an endogenous protein identified through structural and proteomic approaches as the uncharacterized protein NafT. Recognition by endogenous NafT demonstrates the physiological relevance of the HCA-compromised form, perhaps for cofactor insertion or repair. Our results point towards a dynamic active site in which HCA plays a role in enabling nitrogenase catalysis by facilitating activation of the FeMo-cofactor from a relatively stable form to a state capable of reducing dinitrogen under ambient conditions.

PubMed: 36841829
DOI: 10.1038/s41467-023-36636-4

実験手法

ELECTRON MICROSCOPY (2.58 Å)