A Gram-positive red-pigmented, nonmotile, aerobic bacterium that is extremely resistant to a number of agents that damage DNA (ionizing radiation, ultraviolet radiation, and hydrogen peroxide). D. radiodurans can tolerate 3 million rads of ionizing radiation (the human lethal dose is about 500 rads). The D. radiodurans genome is composed of four circular molecules: chromosome 1 (2,649 kb), chromosome 2 (412 kb), a megaplasmid (177 kb), and a plasmid (46 kb). The genome contains 3,187 ORFs, with an average size of 937 kb, and these occupy 91% of the genome. The species possesses a highly efficient DNA repair system that involves about 40 genes, many of which are present in multiple copies. See Classification, Bacteria, Deinococci; Chronology, 1999, White et al.; haploidy.
Subjects: Genetics and Genomics.