ferredoxin hydrogenase activity / 4 iron, 4 sulfur cluster binding / iron ion binding 類似検索 - 分子機能
Iron hydrogenase, small subunit superfamily / Iron hydrogenase, subset / Iron hydrogenase, small subunit / : / Iron hydrogenase small subunit / Iron hydrogenase small subunit / Iron hydrogenase, large subunit, C-terminal / Iron hydrogenase / Iron only hydrogenase large subunit, C-terminal domain / 4Fe-4S dicluster domain ...Iron hydrogenase, small subunit superfamily / Iron hydrogenase, subset / Iron hydrogenase, small subunit / : / Iron hydrogenase small subunit / Iron hydrogenase small subunit / Iron hydrogenase, large subunit, C-terminal / Iron hydrogenase / Iron only hydrogenase large subunit, C-terminal domain / 4Fe-4S dicluster domain / Soluble ligand binding domain / SLBB domain / 4Fe-4S ferredoxin, iron-sulphur binding, conserved site / 4Fe-4S ferredoxin-type iron-sulfur binding region signature. / 4Fe-4S ferredoxin-type iron-sulfur binding domain profile. / 4Fe-4S ferredoxin-type, iron-sulphur binding domain 類似検索 - ドメイン・相同性
ジャーナル: Proc Natl Acad Sci U S A / 年: 2025 タイトル: Structural determinants of oxygen resistance and Zn-mediated stability of the [FeFe]-hydrogenase from . 著者: Jifu Duan / Andreas Rutz / Akihiro Kawamoto / Shuvankar Naskar / Kristina Edenharter / Silke Leimkühler / Eckhard Hofmann / Thomas Happe / Genji Kurisu / 要旨: [FeFe]-hydrogenases catalyze the reversible two-electron reduction of two protons to molecular hydrogen. Although these enzymes are among the most efficient H-converting biocatalysts in nature, their ...[FeFe]-hydrogenases catalyze the reversible two-electron reduction of two protons to molecular hydrogen. Although these enzymes are among the most efficient H-converting biocatalysts in nature, their catalytic cofactor (termed H-cluster) is irreversibly destroyed upon contact with dioxygen. The [FeFe]-hydrogenase CbA5H from has a unique mechanism to protect the H-cluster from oxygen-induced degradation. The protective strategy of CbA5H was proposed based on a partial protein structure of CbA5H's oxygen-shielded form. Here, we present a cryo-EM structure of 2.2 Å resolution from the entire enzyme in its dimeric and active state and elucidate the structural parameters of the reversible cofactor protection mechanism. We found that both subunits of the homodimeric structure of CbA5H have a Zn-binding four-helix domain, which does not play a role in electron transport as described for other complex protein structures. Biochemical data instead confirm that two [4Fe-4S] clusters are responsible for electron transfer in CbA5H, while the identified zinc atom is critical for oligomerization and protein stability.