Novel mutator mutants of E. coli nrdAB ribonucleotide reductase: Insight into allosteric regulation and control of mutation rates

► Mutator mutants of E. coli are described with altered ribonucleotide reductase (RNR). ► RNR mutants display altered dNTP pools and corresponding mutational specificities. ► Mutants are found at the enzyme's allosteric activity and specificity sites. ► A novel regulatory important region is discovered in R2 subunit of RNR.