[Control of homologous recombination by mismatch base repair system in bacteria: implications concerning the chromosome stability and the evolution of species].

The generalized mismatch repair system controls, in bacteria, the homologous recombination between diverged (homologous) DNA. It thus constitute, together with the sequence divergence, a barrier to recombination between bacteria of different species as we have shown for E. coli and S. typhimurium. It is moreover, by preventing the recombination between diverged repeated sequences, a key component of the chromosome stability.