Abstract
Studies of the Class Ib Ribonucleotide Reductase System in Bacillus cereus and Mycobacterium tuberculosis
Ribonucleotide reductases (RNRs) catalyse the reduction of ribonucleotides to their corresponding deoxyribonucleotides, playing a crucial role in DNA repair and replication in all living organisms. Class I RNRs (further subdivided into class Ia, Ib and Ic) require a dinuclear metal cluster for employing a radical chemistry catalytic mechanism. B. cereus and M. tuberculosis both contain the class Ib RNR, require either an iron-or manganese metallocofactor in their radical-generating subunits. The RNR systems in both organisms include a variety of interacting proteins, and biochemical and structural studies of some of these will be presented here. Also, M. tuberculosis includes a second, alternate subunit that might function as an additional radical-generating subunit in its class Ib RNR.