Читать книгу Structure and Function of the Bacterial Genome - Charles J. Dorman - Страница 17

The converging replication forks moving along the chromosome will create a topological problem as they approach one another in the Ter region. As chromosome replication comes to an end, the products that it generates will emerge as intertwined DNA duplexes. This physical linkage must be resolved if it is not to impede chromosome segregation. Furthermore, if homologous recombination occurs between the sister chromosomes it may create a chromosome dimer. This process is made more likely by oxidative damage to DNA, as occurs in mutants defective in the Fur iron regulatory protein (Steiner and Kuempel 1998). The dimers arise from RecBCD‐ and RecFOR‐mediated events with roughly equal frequency (Barre et al. 2001). Once formed, this dimer must be resolved at or before cell division or an anucleate cell will be created (see Section 1.8).