title: Isolation and characterization of rad51 orthologs from Coprinus cinereus and Lycopersicon esculentum, and phylogenetic analysis of eukaryotic recA homologs.
abstract: In eubacteria, the recA gene has long been recognized as essential for homologous recombination and DNA repair. Recent work has identified recA homologs in archaebacteria and eukaryotes, thus emphasizing the universal role this gene plays in DNA metabolism. We have isolated and characterized two new recA homologs, one from the basidiomycete Coprinus cinereus and the other from the angiosperm Lycopersicon esculentum. Like the RAD51 gene of Saccharomyces cerevisiae, the Coprinus gene is highly induced by gamma irradiation and during meiosis. Phylogenetic analyses of eukarotic recA homologs reveal a gene duplication early in eukaryotic evolution which gave rise to two putatively monophyletic groups of recA-like genes. One group of 11 characterized genes, designated the rad51 group, is orthologous to the Saccharomyces RAD51 gene and also contains the Coprinus and Lycopersicon genes. The other group of seven genes, designated the dmc1 group, is orthologous to the Saccharomyces DMC1 gene. Sequence comparisons and phylogenetic analysis reveal extensive lineage- and gene-specific differences in rates of RecA protein evolution. Dmc1 consistently evolves faster than Rad51, and fungal proteins of both types, especially those of Saccharomyces, change rapidly, particularly in comparison to the slowly evolving vertebrate proteins. The Drosophila Rad51 protein has undergone remarkably rapid sequence divergence.
authors.affiliation: Department of Biology, Indiana University, Bloomington, IN 47405, USA.
authors.forename: N Y
authors.initials: NY
authors.lastname: Stassen
authors.forename: J M
authors.initials: JM
authors.lastname: Logsdon
authors.forename: G J
authors.initials: GJ
authors.lastname: Vora
authors.forename: H H
authors.initials: HH
authors.lastname: Offenberg
authors.forename: J D
authors.initials: JD
authors.lastname: Palmer
authors.forename: M E
authors.initials: ME
authors.lastname: Zolan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D015152:Blotting, Northern; D015139:Blotting, Southern; D018797:Cell Cycle Proteins; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003302:Coprinus / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004330:Drosophila / Q000235:genetics; D029721:Drosophila Proteins; D015966:Gene Expression Regulation, Fungal; D018506:Gene Expression Regulation, Plant; D016681:Genome, Fungal; D018551:Solanum lycopersicum / Q000235:genetics*; D008540:Meiosis / Q000235:genetics; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012331:RNA, Fungal / Q000302:isolation & purification; D051135:Rad51 Recombinase; D011938:Rec A Recombinases / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D018797:Cell Cycle Proteins; C513033:DMC1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase; D011938:Rec A Recombinases; C495149:spn-A protein, Drosophila