engleski

Genetic requirements for conjugational recombination in the presence of lambda Gam protein in Escherichia coli

The Gam protein of phage λ is a well-known inhibitor of the enzymatic activities of the RecBCD enzyme, the major enzyme involved in homologous recombination in bacteria Escherichia coli. In this work, we studied (i) the effect of the RecA loading-deficient recB (recBD1080A) mutation on conjugational recombination in the presence of λ phage Gam protein and (ii) additional genetic requirements for the RecBCD Gam-mediated conjugational recombination. For this purpose, we introduced Gam+ and Gam– expressing plasmids into wild type cells and different mutants of E. coli (recJ, recBD1080A, recB, recN, recF, recR, recO, recD), and determined the yields of recombinants after Hfr mediated conjugation. The obtained results suggest that RecA loading activity is not inhibited by Gam and that conjugational recombination in the presence of Gam is partially dependent on recJ and recO gene products.

Escherichia coli; phage lambda; conjugational recombination; RecBCD enzyme; Gam protein

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