Radical Transport Facilitated by a Proton Transfer Network at the Subunit Interface of Ribonucleotide Reductase.

ABSTRACT: Ribonucleotide reductases (RNRs) play an essential role in the conversion of nucleotides to deoxynucleotides in all organisms. The Escherichia coli class Ia RNR requires two homodimeric subunits, α and β. The active form is an asymmetric αα'ββ' complex. The α subunit houses the site for nucleotide reduction initiated by a thiyl radical (C₄₃₉•), and the β subunit houses the diferric-tyrosyl radical (Y₁₂₂•) that is essential for C₄₃₉• formation. The reactions require a highly regulated and reversible long-range proton-coupled electron transfer pathway involving Y₁₂₂•[β] ↔ W₄₈?[β] ↔ Y₃₅₆[β] ↔ Y₇₃₁[α] ↔ Y₇₃₀[α] ↔ C₄₃₉[α]. In a recent cryo-EM structure, Y₃₅₆[β] was revealed for t

SUBMITTER: Cui C 

PROVIDER: S-EPMC10561588 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature