title: The Schizosaccharomyces pombe rhp3+ gene required for DNA repair and cell viability is functionally interchangeable with the RAD3 gene of Saccharomyces cerevisiae.
abstract: The RAD3 gene of Saccharomyces cerevisiae is required for excision repair and is essential for cell viability. RAD3 encoded protein possesses a single stranded DNA-dependent ATPase and DNA and DNA.RNA helicase activities. Mutational studies have indicated a requirement for the RAD3 helicase activities in excision repair. To examine the extent of conservation of structure and function of RAD3 during eukaryotic evolution, we have cloned the RAD3 homolog, rhp3+, from the distantly related yeast Schizosaccharomyces pombe. RAD3 and rhp3+ encoded proteins are highly similar, sharing 67% identical amino acids. We show that like RAD3, rhp3+ is indispensable for excision repair and cell viability, and our studies indicate a requirement of the putative rhp3+ DNA helicase activity in DNA repair. We find that the RAD3 and rhp3+ genes can functionally substitute for one another. The level of complementation provided by the rhp3+ gene in S.cerevisiae rad3 mutants or by the RAD3 gene in S.pombe rhp3 mutants is remarkable in that both the excision repair and viability defects in both yeasts are restored to wild type levels. These observations suggest a parallel evolutionary conservation of other protein components with which RAD3 interacts in mediating its DNA repair and viability functions.
authors.affiliation: Department of Biophysics, University of Rochester School of Medicine, NY 14642-8408.
authors.forename: P R
authors.initials: PR
authors.lastname: Reynolds
authors.forename: S
authors.initials: S
authors.lastname: Biggar
authors.forename: L
authors.initials: L
authors.lastname: Prakash
authors.forename: S
authors.initials: S
authors.lastname: Prakash
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D004265:DNA Helicases; D004260:DNA Repair / Q000235:genetics*; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000235:genetics*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011506:Proteins; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D029702:Schizosaccharomyces pombe Proteins; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors; D014466:Ultraviolet Rays; D051759:Xeroderma Pigmentosum Group D Protein
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009687:Nuclear Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C094155:Rad15 protein, S pombe; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human