Nitrogenase iron protein NifH / NifH/frxC family / NifH/chlL conserved site / 4Fe-4S iron sulfur cluster binding proteins, NifH/frxC family / NifH/frxC family signature 2. / NifH/frxC family signature 1. / NIFH_FRXC family profile. / Nitrogenase molybdenum-iron protein beta chain, N-terminal / Domain of unknown function (DUF3364) / Nitrogenase molybdenum-iron protein alpha chain ...Nitrogenase iron protein NifH / NifH/frxC family / NifH/chlL conserved site / 4Fe-4S iron sulfur cluster binding proteins, NifH/frxC family / NifH/frxC family signature 2. / NifH/frxC family signature 1. / NIFH_FRXC family profile. / Nitrogenase molybdenum-iron protein beta chain, N-terminal / Domain of unknown function (DUF3364) / Nitrogenase molybdenum-iron protein alpha chain / Nitrogenase molybdenum-iron protein beta chain / Nitrogenase component 1, alpha chain / Nitrogenase component 1, conserved site / Nitrogenases component 1 alpha and beta subunits signature 2. / Nitrogenases component 1 alpha and beta subunits signature 1. / Nitrogenase/oxidoreductase, component 1 / : / Nitrogenase component 1 type Oxidoreductase / 2Fe-2S ferredoxin, iron-sulphur binding site / 2Fe-2S ferredoxin-type iron-sulfur binding region signature. / 2Fe-2S iron-sulfur cluster binding domain / Beta-grasp domain superfamily / 2Fe-2S ferredoxin-type iron-sulfur binding domain profile. / 2Fe-2S ferredoxin-type iron-sulfur binding domain / 2Fe-2S ferredoxin-like superfamily / P-loop containing nucleoside triphosphate hydrolase 類似検索 - ドメイン・相同性
Nitrogenase iron protein 1 / Nitrogenase molybdenum-iron protein alpha chain / Nitrogenase molybdenum-iron protein beta chain / Protein FeSII 類似検索 - 構成要素
ジャーナル: Nature / 年: 2025 タイトル: Conformational protection of molybdenum nitrogenase by Shethna protein II. 著者: Philipp Franke / Simon Freiberger / Lin Zhang / Oliver Einsle / 要旨: The oxygen-sensitive molybdenum-dependent nitrogenase of Azotobacter vinelandii is protected from oxidative damage by a reversible 'switch-off' mechanism. It forms a complex with a small ferredoxin, ...The oxygen-sensitive molybdenum-dependent nitrogenase of Azotobacter vinelandii is protected from oxidative damage by a reversible 'switch-off' mechanism. It forms a complex with a small ferredoxin, FeSII (ref. ) or the 'Shethna protein II', which acts as an O sensor and associates with the two component proteins of nitrogenase when its [2Fe:2S] cluster becomes oxidized. Here we report the three-dimensional structure of the protective ternary complex of the catalytic subunit of Mo-nitrogenase, its cognate reductase and the FeSII protein, determined by single-particle cryo-electron microscopy. The dimeric FeSII protein associates with two copies of each component to assemble a 620 kDa core complex that then polymerizes into large, filamentous structures. This complex is catalytically inactive, but the enzyme components are quickly released and reactivated upon oxygen depletion. The first step in complex formation is the association of FeSII with the more O-sensitive Fe protein component of nitrogenase during sudden oxidative stress. The action of this small ferredoxin represents a straightforward means of protection from O that may be crucial for the maintenance of recombinant nitrogenase in food crops.