Functional characterization of a DNA repair polymerase from a radiation resistant bacterium, Deinococcus radiodurans

Cells exposed to DNA damaging agents, produce different types of structural changes in the chromosome. Repair of these lesions requires synthesis of new DNA molecules, catalysed by specific DNA polymerases. A putative DNA polymerase has been characterized, for its role in DNA damage repair and radiation resistance in D. radiodurans, a bacterium best known for its extraordinary resistance to  radiation. Transgenic Escherichia coli expressing this protein, showed an improved tolerance to both ionizing and non-ionizing radiations while D. radiodurans cells devoid of this protein become sensitive to DNA damage. Molecular studies suggest, this enzyme’s involvement in base excision repair, a crucial process requires for correcting the DNA damage due to oxidative stress in all living systems.