Evidence that SbcB and RecF pathway functions contribute to RecBCD-dependent transductional recombination.

摘要: A role for the RecF, RecJ, and SbcB proteins in RecBCD-dependent recombination pathway is suggested on basis of effect null recF, recJ, sbcB mutations Salmonella typhimurium a "short-homology" P22 transduction assay. The assay requires within short (approximately 3-kb) sequences that flank selected marker lie at ends transduced fragment. Since these are subject to exonucleolytic degradation, may demand rapid by requiring exchange be completed before essential recombining degraded. In this assay, mutations, tested individually, cause small decrease recombinant recovery but all pairwise combinations 10- 30-fold reduction. recD mutant recipient, which shows increased recombination, mutation 100-fold reduction recovery. standard (about 20 kb flanking sequence), have very frequency. We suggest three promote rate-limiting step RecBC-dependent process. above results were obtained with lysogenic recipient strain represses expression superinfecting phage genomes minimizes contribution functions. When nonlysogenic used, coinfecting express functions alter genetic requirements short-homology