4XPI

Fe protein independent substrate reduction by nitrogenase variants altered in intramolecular electron transfer

4XPI の概要

• エントリーDOI: 10.2210/pdb4xpi/pdb
• 分子名称: Nitrogenase molybdenum-iron protein alpha chain, Nitrogenase molybdenum-iron protein beta chain, 3-HYDROXY-3-CARBOXY-ADIPIC ACID, ... (9 entities in total)
• 機能のキーワード: nitrogen fixation, mofe protein, nitrogenase, proton reduction, nitrogen, acetylene, hydride reduction, atp-binding, iron, iron-sulfur, metal-binding, nucleotide-binding, oxidoreductase, molybdenum
• 由来する生物種: Azotobacter vinelandii; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 234056.28

構造登録者

Danyal, K.,Rasmusen, A.J.,Keable, S.M.,Shaw, S.,Zadvornyy, O.,Duval, S.,Dean, D.R.,Raugei, S.,Peters, J.W.,Seefeldt, L.C. (登録日: 2015-01-17, 公開日: 2015-10-14, 最終更新日: 2023-09-27)

主引用文献

Danyal, K.,Rasmussen, A.J.,Keable, S.M.,Inglet, B.S.,Shaw, S.,Zadvornyy, O.A.,Duval, S.,Dean, D.R.,Raugei, S.,Peters, J.W.,Seefeldt, L.C.
Fe protein-independent substrate reduction by nitrogenase MoFe protein variants.
Biochemistry, 54:2456-2462, 2015

PubMed Abstract: The reduction of substrates catalyzed by nitrogenase normally requires nucleotide-dependent Fe protein delivery of electrons to the MoFe protein, which contains the active site FeMo cofactor. Here, it is reported that independent substitution of three amino acids (β-98(Tyr→His), α-64(Tyr→His), and β-99(Phe→His)) located between the P cluster and FeMo cofactor within the MoFe protein endows it with the ability to reduce protons to H2, azide to ammonia, and hydrazine to ammonia without the need for Fe protein or ATP. Instead, electrons can be provided by the low-potential reductant polyaminocarboxylate-ligated Eu(II) (Em values of -1.1 to -0.84 V vs the normal hydrogen electrode). The crystal structure of the β-98(Tyr→His) variant MoFe protein was determined, revealing only small changes near the amino acid substitution that affect the solvent structure and the immediate vicinity between the P cluster and the FeMo cofactor, with no global conformational changes observed. Computational normal-mode analysis of the nitrogenase complex reveals coupling in the motions of the Fe protein and the region of the MoFe protein with these three amino acids, which suggests a possible mechanism for how Fe protein might communicate subtle changes deep within the MoFe protein that profoundly affect intramolecular electron transfer and substrate reduction.

PubMed: 25831270
DOI: 10.1021/acs.biochem.5b00140

実験手法

X-RAY DIFFRACTION (1.97 Å)