A recombination repair gene of Schizosaccharomyces pombe, rhp57, is a functional homolog of the Saccharomyces cerevisiae RAD57 gene and is phylogenetically related to the human XRCC3 gene.
To identify Schizosaccharomyces pombe genes involved in recombination repair, we identified seven mutants that were hypersensitive to both methyl methanesulfonate (MMS) and gamma-rays and that contained mutations that caused synthetic lethality when combined with a rad2 mutation. One of the mutants was used to clone the corresponding gene from a genomic library by complementation of the MMS-sensitive phenotype. The gene obtained encodes a protein of 354 amino acids whose sequence is 32% identical to that of the Rad57 protein of Saccharomyces cerevisiae. An rhp57 (RAD57 homolog of S. pombe) deletion strain was more sensitive to MMS, UV, and gamma-rays than the wild-type strain and showed a reduction in the frequency of mitotic homologous recombination. The MMS sensitivity was more severe at lower temperature and was suppressed by the presence of a multicopy plasmid bearing the rhp51 gene. An rhp51 rhp57 double mutant was as sensitive to UV and gamma-rays as an rhp51 single mutant, indicating that rhp51 function is epistatic to that of rhp57. These characteristics of the rhp57 mutants are very similar to those of S. cerevisiae rad57 mutants. Phylogenetic analysis suggests that Rhp57 and Rad57 are evolutionarily closest to human Xrcc3 of the RecA/Rad51 family of proteins.
Tsutsui
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Y
Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
Morishita
T
T
Iwasaki
H
H
Toh
H
H
Shinagawa
H
H
D000251:Adenosine Triphosphatases; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004271:DNA, Fungal; D004268:DNA-Binding Proteins / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics*; D005804:Genes, Lethal; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010641:Phenotype; D010802:Phylogeny; D011995:Recombination, Genetic / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; C110901:X-ray repair cross complementing protein 3; D000251:Adenosine Triphosphatases; C071451:RAD57 protein, S cerevisiae; D045643:DNA Repair Enzymes