A Structurally Divergent Class Ia Ribonucleotide Reductase from a Tick-Borne Pathogen.

ABSTRACT: Ribonucleotide reductases (RNRs) generate 2'-deoxynucleotides for DNA biosynthesis, a reaction essential to all life. Class I RNRs have two subunits, α and β. α binds and reduces the substrate, whereas β oxidizes one of the cysteines in α to a C3'-H-bond-cleaving thiyl radical to begin the reaction. The α-Cys oxidant in β is variously a tyrosyl radical (Y^•) generated by a diiron or dimanganese cluster, a high-valent dimetal cluster [Mn(IV)/Fe(III) or Mn₂(IV/III)], or a dihydroxylphenylalanine (DOPA) radical that operates without need of a transition metal. The metal (in)dependence of the Cys oxidant in β correlates loosely with sequence-similarity groupings. We show here that Francisella hispaniensis (Fh) β, which lies within an uncharacterized sequence

SUBMITTER: Peduzzi OM 

PROVIDER: S-EPMC12453626 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature