6OP2

Selenium incorporated FeMo-cofactor of nitrogenase from azotobacter vinelandii at high concentration of selenium

6OP2 の概要

• エントリーDOI: 10.2210/pdb6op2/pdb
• 分子名称: Nitrogenase molybdenum-iron protein alpha chain, Nitrogenase molybdenum-iron protein beta chain, 3-HYDROXY-3-CARBOXY-ADIPIC ACID, ... (10 entities in total)
• 機能のキーワード: nitrogenase, selenium, femo-cofactor, oxidoreductase
• 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: 231186.74

構造登録者

Arias, R.J.,Rees, D.C. (登録日: 2019-04-24, 公開日: 2019-08-14, 最終更新日: 2023-10-11)

主引用文献

Henthorn, J.T.,Arias, R.J.,Koroidov, S.,Kroll, T.,Sokaras, D.,Bergmann, U.,Rees, D.C.,DeBeer, S.
Localized Electronic Structure of Nitrogenase FeMoco Revealed by Selenium K-Edge High Resolution X-ray Absorption Spectroscopy.
J.Am.Chem.Soc., 141:13676-13688, 2019

PubMed Abstract: The size and complexity of Mo-dependent nitrogenase, a multicomponent enzyme capable of reducing dinitrogen to ammonia, have made a detailed understanding of the FeMo cofactor (FeMoco) active site electronic structure an ongoing challenge. Selective substitution of sulfur by selenium in FeMoco affords a unique probe wherein local Fe-Se interactions can be directly interrogated via high-energy resolution fluorescence detected X-ray absorption spectroscopic (HERFD XAS) and extended X-ray absorption fine structure (EXAFS) studies. These studies reveal a significant asymmetry in the electronic distribution of the FeMoco, suggesting a more localized electronic structure picture than is typically assumed for iron-sulfur clusters. Supported by experimental small molecule model data in combination with time dependent density functional theory (TDDFT) calculations, the HERFD XAS data is consistent with an assignment of Fe2/Fe6 as an antiferromagnetically coupled diferric pair. HERFD XAS and EXAFS have also been applied to Se-substituted CO-inhibited MoFe protein, demonstrating the ability of these methods to reveal electronic and structural changes that occur upon substrate binding. These results emphasize the utility of Se HERFD XAS and EXAFS for selectively probing the local electronic and geometric structure of FeMoco.

PubMed: 31356071
DOI: 10.1021/jacs.9b06988

実験手法

X-RAY DIFFRACTION (1.9 Å)