A homolog of Escherichia coli RecA in mitochondria of the cellular slime mold Dictyostelium discoideum

DNA Repair (Amst). 2004 May 4;3(5):515-25. doi: 10.1016/j.dnarep.2004.01.014.

Abstract

The cellular slime mold Dictyostelium discoideum expresses a gene encoding a 452-amino-acid polypeptide that is 47% identical to Escherichia coli RecA. A recA-deficient E. coli, JE6651, was transformed by pYSN1, which was designed to express the truncated form of the D. discoideum gene, and used in suppression assays. The viability of the transformant, JE6651(pYSN1), increased following UV irradiation or mitomycin C treatment. Phage lambda (red(-) gam(-)), which required RecA activity for DNA packaging, formed plaques on a lawn of JE6651(pYSN1). These results indicate that the gene product has a DNA recombination activity. Fluorescence of D. discoideum protein fused with GFP was detected in mitochondria. The gene disruption mutant was hypersensitive to UV-light (254nm), mitomycin C and H(2)O(2), indicating that D. discoideum recA is important for survival following exposure to DNA damaging agents.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • DNA Damage / drug effects
  • DNA Damage / radiation effects
  • Dictyostelium / cytology
  • Dictyostelium / drug effects
  • Dictyostelium / enzymology*
  • Dictyostelium / genetics
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Hydrogen Peroxide / pharmacology
  • Mitochondria / metabolism*
  • Molecular Sequence Data
  • Mutation / genetics
  • Protein Transport
  • Rec A Recombinases / chemistry
  • Rec A Recombinases / genetics*
  • Rec A Recombinases / metabolism*
  • Ultraviolet Rays

Substances

  • Hydrogen Peroxide
  • Rec A Recombinases