Kinetics of transient radicals in Escherichia coli ribonucleotide reductase : Formation of a new tyrosyl radical in mutant protein R2
Reconstitution of the tyrosyl radical in ribonucleotide reductase protein R2 requires oxidation of a diferrous site by oxygen. The reaction involves one externally supplied electron in addition to the three electrons provided by oxidation of the Tyr-122 side chain and formation of the μ-oxo- bridged diferric site. Reconstitution of R2 protein Y122F, lacking the internal pathway involving Tyr-122,