5KOJ

Nitrogenase MoFeP protein in the IDS oxidized state

5KOJ の概要

• エントリーDOI: 10.2210/pdb5koj/pdb
• 関連するPDBエントリー: 5KOH
• 分子名称: Nitrogenase protein alpha chain, Nitrogenase FeMo beta subunit protein NifK, 3-HYDROXY-3-CARBOXY-ADIPIC ACID, ... (7 entities in total)
• 機能のキーワード: nitrogenase, electron transfer, oxidoreductase, p-cluster
• 由来する生物種: Gluconacetobacter diazotrophicus (strain ATCC 49037 / DSM 5601 / PAl5); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 229820.93

構造登録者

Owens, C.P.,Tezcan, F.A. (登録日: 2016-06-30, 公開日: 2016-09-14, 最終更新日: 2024-03-06)

主引用文献

Owens, C.P.,Katz, F.E.,Carter, C.H.,Oswald, V.F.,Tezcan, F.A.
Tyrosine-Coordinated P-Cluster in G. diazotrophicus Nitrogenase: Evidence for the Importance of O-Based Ligands in Conformationally Gated Electron Transfer.
J.Am.Chem.Soc., 138:10124-10127, 2016

PubMed Abstract: The P-cluster is a unique iron-sulfur center that likely functions as a dynamic electron (e(-)) relay site between the Fe-protein and the catalytic FeMo-cofactor in nitrogenase. The P-cluster has been shown to undergo large conformational changes upon 2-e(-) oxidation which entail the coordination of two of the Fe centers to a Ser side chain and a backbone amide N, respectively. Yet, how and if this 2-e(-) oxidized state (P(OX)) is involved in catalysis by nitrogenase is not well established. Here, we present the crystal structures of reduced and oxidized MoFe-protein (MoFeP) from Gluconacetobacter diazotrophicus (Gd), which natively possesses an Ala residue in the position of the Ser ligand to the P-cluster. While reduced Gd-MoFeP is structurally identical to previously characterized counterparts around the FeMo-cofactor, oxidized Gd-MoFeP features an unusual Tyr coordination to its P-cluster along with ligation by a backbone amide nitrogen. EPR analysis of the oxidized Gd-MoFeP P-cluster confirmed that it is a 2-e(-) oxidized, integer-spin species. Importantly, we have found that the sequence positions corresponding to the Ser and Tyr ligands are almost completely covariant among Group I nitrogenases. These findings strongly support the possibility that the P(OX) state is functionally relevant in nitrogenase catalysis and that a hard, O-based anionic ligand serves to stabilize this state in a switchable fashion.

PubMed: 27487256
DOI: 10.1021/jacs.6b06783

実験手法

X-RAY DIFFRACTION (2.592 Å)