Characterization of DRA0282 from Deinococcus radiodurans for its role in bacterial resistance to DNA damage

Microbiology (Reading). 2011 Aug;157(Pt 8):2196-2205. doi: 10.1099/mic.0.040436-0. Epub 2011 Apr 21.


DRA0282, a hypothetical protein, was found in a pool of nucleotide-binding proteins in Deinococcus radiodurans cells recovering from gamma radiation stress. This pool exhibited an unusual inhibition of nuclease activity by ATP. The N terminus of DRA0282 showed similarity to human Ku80 homologues, while the C terminus showed no similarities to known proteins. The recombinant protein required Mn(2+) for its interaction with DNA and protected dsDNA from exonuclease III degradation. The binding of the protein to supercoiled DNA with a K(d) of ~2.93 nM was nearly 20-fold stronger than its binding to ssDNA and nearly 67-fold stronger than its binding to linear dsDNA. Escherichia coli cells expressing DRA0282 showed a RecA-dependent enhancement of UV and gamma radiation tolerance. The ΔdrA0282 mutant of D. radiodurans showed a dose-dependent response to gamma radiation. At 14 kGy, the ΔdrA0282 mutant showed nearly 10-fold less survival, while at this dose both pprA : : catΔdrA0282 and pprA : : cat mutants were nearly 100-fold more sensitive than the wild-type. These results suggested that DRA0282 is a DNA-binding protein with a preference for superhelical DNA, and that it plays a role in bacterial resistance to DNA damage through a pathway in which PprA perhaps plays a dominant role in D. radiodurans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Cations, Divalent / metabolism
  • Cloning, Molecular
  • Coenzymes / metabolism
  • DNA / metabolism
  • DNA Damage*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Deinococcus / genetics
  • Deinococcus / metabolism*
  • Deinococcus / radiation effects*
  • Escherichia coli / genetics
  • Escherichia coli / radiation effects
  • Gene Deletion
  • Gene Expression
  • Kinetics
  • Manganese / metabolism
  • Microbial Viability / radiation effects
  • Models, Molecular
  • Protein Binding
  • Protein Conformation
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism


  • Bacterial Proteins
  • Cations, Divalent
  • Coenzymes
  • DNA-Binding Proteins
  • Recombinant Proteins
  • Manganese
  • DNA