Effect of mutations in recB, recC, sbcB and recF genes controlling the homologous recombination in Escherichia coli cells on transposition of Tn1

The mutations in the genes controlling the homologous DNA recombination in Escherichia coli cells effect the efficiency of Tn1 transposition. Mutations in recB and recC genes decrease 50-fold the frequencies of Tn1 transposition. Introduction of an additional mutation in sbcB gene increase transposition frequency for three orders as compared with the one registered in wild type cells. Inactivation of sbcB gene in the wild type cells does not affect transposition significantly. Mutation in recF gene results in the great decrease of transposition when it is introduced into multiple recBC sbcB mutant, but not into the wild type bacteria. The possibility of two pathways for Tn1 transposition existing in Escherichia coli cells is discussed, as well as possibility of existence of similar stages in transposition and recombination controlled by the same genes.