Cloning and characterization of a DNA repair gene in Haemophilus influenzae.

ABSTRACT

Using a high-efficiency DNA cloning vector pJ1-8, a DNA repair gene uvr1 has been self-cloned in bacterium Haemophilus influenzae. Chimeric plasmid pKuvrl, carrying wild type allele of uvr1 gene and flanking DNA sequences, specifically complements a uvrl gene mutation in the bacterial chromosome. A uvr1– mutation could be transferred from chromosome by in vivo recombination to pKuvr1 and isolated and designated as plasmid pKuvrl –. Plasmid pKuvrl carries a 11·3 kb chromosomal DNA insert which was scanned for the presence of any other DNA repair genes by a novel method of directed mutagenesis. Preliminary analysis of the 3 new mutants isolated by this method supports the notion that the insert contains more than one gene concerned with ultraviolet radiation-sensitivity.