An engineered two-iron superoxide reductase lacking the [Fe(SCys)4] site retains its catalytic properties in vitro and in vivo.

ABSTRACT: Superoxide reductases (SORs) contain a characteristic square-pyramidal [Fe(NHis)(4)(SCys)] active site that catalyzes reduction of superoxide to hydrogen peroxide in several anaerobic bacteria and archaea. Some SORs, referred to as two-iron SORs (2Fe-SORs), also contain a lower-potential [Fe(SCys)(4)] site that is presumed to have an electron transfer function. However, the intra- and inter-subunit distances between [Fe(SCys)(4)] and [Fe(NHis)(4)(SCys)] iron centers within the 2Fe-SOR homodimer seem too long for efficient electron transfer between these sites. The possible role of the [Fe(SCys)(4)] site in 2Fe-SORs was addressed in this work by examination of an engineered Desulfovibrio vulgaris 2Fe-SOR variant, C13S, in which one ligand residue of the [Fe(SCys)(4)] site, cysteine 13, was

SUBMITTER: Emerson JP 

PROVIDER: S-EPMC153002 | biostudies-literature | 2003 Apr

REPOSITORIES: biostudies-literature