title: A homolog of Escherichia coli RecA in mitochondria of the cellular slime mold Dictyostelium discoideum.
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.
authors.affiliation: Division of Bioengineering, Faculty of Engineering, Toyama University, Toyama 930-8555, Japan.
authors.forename: Yasuna
authors.initials: Y
authors.lastname: Hasegawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Wakabayashi
authors.forename: Shogo
authors.initials: S
authors.lastname: Nakamura
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kodaira
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shinohara
authors.forename: Hiro
authors.initials: H
authors.lastname: Yasukawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004249:DNA Damage / Q000187:drug effects / Q000528:radiation effects; D004023:Dictyostelium / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D021381:Protein Transport; D011938:Rec A Recombinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D006861:Hydrogen Peroxide; D011938:Rec A Recombinases