Three pathways for genetic recombination in bacteria uses the protein RecA. However, in each case, a different set of steps precedes the action of RecA, in catalyzing strand invasion. One of these pathways utilizes an enzyme complex called RecBCD, which binds to double-strand breaks in DNA and exhibit both helicase and single strand nuclease activity. When bacterial cells are co-infected with 2 different strains of bacteriophage l, genes located near certain regions of phage DNA, called CHI sites, recombine at much higher frequencies than other genes do. However, in mutant bacteria lacking RecBCD, genes located near CHI sites recombine at the same frequencies as the other genes. Briefly describe a model of recombination with the above information.
Three pathways for genetic recombination in bacteria uses the protein RecA. However, in each case, a different set of steps precedes the action of RecA, in catalyzing strand invasion. One of these pathways utilizes an enzyme complex called RecBCD, which binds to double-strand breaks in DNA and exhibit both helicase and single strand nuclease activity. When bacterial cells are co-infected with 2 different strains of bacteriophage l, genes located near certain regions of phage DNA, called CHI sites, recombine at much higher frequencies than other genes do. However, in mutant bacteria lacking RecBCD, genes located near CHI sites recombine at the same frequencies as the other genes. Briefly describe a model of recombination with the above information.
