Identification of a Multiprotein Dna Metabolic Complex from a Radioresistant Bacterium Deinococcus Radiodurans

Deinococcus radiodurans R1 (DEIRA) a member of Deinococcae family can survive ~12 kGy dose of γ radiation which can generate about 200 double strands and 3000 single strand breaks per genome. An efficient DNA strand break repair, contributes maximum to the radioresistance of Deinococcus radiodurans. Distinction in DNA strand break repair from others seems to lie in the mechanism of action of DNA metabolic proteins, in DNA catabolic and anabolic processes, involved in DNA strand break repair. Here, we report the identification of a multiprotein complex comprised of 15 proteins, from Deinococcus radiodurans. The complex showed DNA ends processing and end joining activities. Biochemical and immunological characterization showed the presence of several DNA repair proteins including PprA, DNA polymerase and DNA ligase. Complex lacked RecA but has three uncharacterized phosphoproteins. The results suggest the presence of various DNA metabolic proteins required for DNA repair functions, in the form of an active multiprotein complex and the regulation of DNA degradation function by high energy phosphate. IDENTIFICATION OF A MULTIPROTEIN DNA METABOLIC COMPLEX FROM A RADIORESISTANT BACTERIUM DEINOCOCCUS RADIODURANS Swathi Kota and Hari S. Misra Molecular Biology Division Bhabha Atomic Research Centre This paper was awarded the Best Poster Prize at the International Symposium on Frontiers in Genetics and Biotechnology-Retrospect and Prospect held at Osmania University, Hyderabad during January 8-10, 2006