H-cluster Intermediates and Catalytic Properties of <i>Clostridium pasteurianum</i> [FeFe]-Hydrogenase III.

ABSTRACT: [FeFe]-Hydrogenases are structurally diverse enzymes that catalyze reversible H₂ activation at a catalytic cofactor or H-cluster. The H-cluster is a [4Fe-4S] cubane linked by a cysteine thiolate to a diiron subsite containing unique CO, CN^-, and dithiomethylamine ligands. The established H-cluster resting state of [4Fe-4S]²⁺-[Fe^II-Fe^I], or H_ox, functions in H₂ binding and oxidation, or by proton-coupled reduction initiates H₂ evolution. In contrast, in Clostridium pasteurianum [FeFe]-hydrogenase III (CpIII) the resting state of the H-cluster is fully oxidized, [4Fe-4S]²⁺-[Fe^II-Fe^II], or H_ox+1. To begin to understand if H_ox+1 has a role in the

SUBMITTER: Kisgeropoulos EC 

PROVIDER: S-EPMC12138974 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature