Isolation and characterization of a novel Deinococcus radiodurans mutant abnormally susceptible to mutation induction by UV, gamma-ray, and mitomycin C

Abstract

We isolated and characterized a novel, radiation 'hypermutable' mutant of Deinococcus radiodurans. Compared with the wild-type strain D. radiodurans IR, this mutator strain, designated S101, exhibited sensitivity to UV light, gamma-ray, mitomycin C, and N -methyl- N -nitro- N -nitrosoguanidine. Spontaneous revertants of S101 that restored wild-type phenotype (non-mutability and resistance to these DNAdamaging agents) were also isolated. Furthermore, the increased susceptibility to DNA-damaging agents and mutability observed in S101 could be mimicked by treating D. radiodurans IR with Mn(II) ions. Our results suggest a putative new pathway of DNA repair in the extremely radioresistant bacterium D. radiodurans.