title: Escherichia coli mutants uvr D and uvr E deficient in gene conversion of lambda-heteroduplexes.
abstract: Calcium-treated cells of E. coli K-12 C600 were transfected with lambda-heteroduplex DNA carrying the marker cIts857 in one strand and wildtype in the other. In single burst analyses of the phage progeny, 72-79% of the bursts were "pure" bursts containing either exclusively wildtype phage or exclusively mutant phage, indicating that conversion of the cIts857/+ mismatch to a homoduplex structure prior to replication occurred with this frequency. The r-strand1 appears to be "preferred", since pure bursts of progeny with the r-strand genotype were almost twice as frequent as those with the l-strand genotype. Examination of the conversion frequency of a number of rec and uvr E. coli mutants showed that the mutants uvr D and UVR E are deficient in mismatch repair. Conversion is reduced in the former by a factor of 2 and in the latter by a factor of 3.
mesh_terms: D002118:Calcium / Q000494:pharmacology; D003090:Coliphages / Q000502:physiology*; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology; D005838:Genotype; D008242:Lysogeny; D009154:Mutation; D010641:Phenotype; D011995:Recombination, Genetic; D014161:Transduction, Genetic
chemical_list: D004279:DNA, Viral; D002118:Calcium