An analysis of DNA repair and recombination functions of bacteriophage T4 by means of suppressors: The role of das

Previous studies have indicated that the bacteriophage T4 das mutations partially suppressed the DNA replication defects in gene 46 and 47 mutations. Here it is shown that the das mutation also suppresses the DNA repair defects but not the DNA replication defects of the uvsX and uvsY mutations. In contrast, the das mutation suppressed both the DNA replication and repair defects of gene 46 and 47 mutations. These characteristics of das as well as those of the other suppressors, including uvsW( dar) and two new suppressors sur and uvsU have been used for the analysis of the DNA repair pathway. Based on the functions of these suppressors, a sequence in which the gene products in this pathway might act is suggested.