title: Expression and complementation analyses of a chloroplast-localized homolog of bacterial RecA in the moss Physcomitrella patens.
abstract: RecA protein is widespread in bacteria, and it plays a crucial role in homologous recombination. We have identified two bacterial-type recA gene homologs (PprecA1, PprecA2) in the cDNA library of the moss Physcomitrella patens. N-terminal fusion of the putative organellar targeting sequence of PpRecA2 to the green fluorescent protein (GFP) caused a targeting of PpRecA2 to the chloroplasts. Mutational analysis showed that the first AUG codon acts as initiation codon. Fusion of the full-length PpRecA2 to GFP caused the formation of foci that were colocalized with chloroplast nucleoids. The amounts of PprecA2 mRNA and protein in the cells were increased by treatment with DNA damaging agents. PprecA2 partially complemented the recA mutation in Escherichia coli. These results suggest the involvement of PpRecA2 in the repair of chloroplast DNA.
authors.affiliation: Department of Life Science, College of Science, Rikkyo (St. Paul's) University, Tokyo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Inouye
authors.forename: Masaki
authors.initials: M
authors.lastname: Odahara
authors.forename: Tomomichi
authors.initials: T
authors.lastname: Fujita
authors.forename: Mitsuyasu
authors.initials: M
authors.lastname: Hasebe
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Sekine
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D019068:Bryopsida / Q000166:cytology / Q000235:genetics*; D002736:Chloroplasts / Q000378:metabolism*; D004249:DNA Damage / Q000235:genetics; D004926:Escherichia coli; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011938:Rec A Recombinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D011938:Rec A Recombinases