Cloning of photoreactivation repair gene and excision repair gene of the yeast Saccharomyces cerevisiae

Summary The photoreactivation repair gene (PHR1) of the yeast Saccharomyces cerevisiae was cloned in a hybrid plasmid (pJDB207), which is able to replicate as a multicopy episome in S. cerevisiae and Escherichia coli cells. The size of the DNA fragment found to have the photoreactivation activity was 3.0 kb, determined by recloning of the isolated fragment. In wild type cells transformed by the plasmid containing the PHR1 gene, the number of DNA photolyase molecules was 15 times greater than in wild type cells with pJDB207 only. Using the same receptor strain the excision repair gen RAD1 was also isolated. The size of the insert of the DNA which complements excision repair deficiency in recipient yeast cells was 5.7 kb. The recipient cells after transformation with the plasmid containing RAD1 showed the same UV-sensitivty as wild type cells with pJDB207 only.Abbreviation UV Ultra-violet light of 254 run wavelength