Photochemical Rescue of a Conformationally Inactivated Ribonucleotide Reductase.

ABSTRACT: Class Ia ribonucleotide reductase (RNR) of Escherichia coli contains an unusually stable tyrosyl radical cofactor in the β₂ subunit (Y₁₂₂^•) necessary for nucleotide reductase activity. Upon binding the cognate α₂ subunit, loaded with nucleoside diphosphate substrate and an allosteric/activity effector, a rate determining conformational change(s) enables rapid radical transfer (RT) within the active α₂β₂ complex from the Y₁₂₂^• site in β₂ to the substrate activating cysteine residue (C₄₃₉) in α₂ via a pathway of redox active amino acids (Y₁₂₂[β] ↔ W₄₈[β]? ↔ Y₃₅₆[β] ↔ Y₇₃₁[α] ↔ Y₇₃₀[α] ↔ C₄₃₉[α]) spanning >35

SUBMITTER: Greene BL 

PROVIDER: S-EPMC6249109 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature