... man-ganese in the transcriptional regulation of the nrdoperon [35] may not be considered in the light of the results obtained in the present study. Rather, the involvement of manganese in the in vivo ... to the catalytic site of the R1E subunit. Asreported in the Results, upon completion of substrateconversion, the radical is then rapidly passed backfrom the R1E subunit to the tyrosyl of the ... RNR and that of other class 1RNRs or, instead, is a result of the interaction of the R2F with the inactivated (oxidized) form of the R1E.We consider the first option unlikely. Under these cir-cumstances,...