Fuse or die: how to survive the loss of Dam in Vibrio cholerae
2014
Val, Marie-Eve | Kennedy, Sean Patrick | Soler-Bistué, Alfonso | Barbe, Valérie | Bouchier, Christiane | Ducos-Galand, Magaly | Skovgaard, Ole | Mazel, Didier | Plasticité du Génome Bactérien - Bacterial Genome Plasticity (PGB) ; Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS) | MetaGenoPolis ; Institut National de la Recherche Agronomique (INRA) | Genoscope - Centre national de séquençage [Evry] (GENOSCOPE) ; Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) | Department of Science, Systems and Models ; Roskilde Universitet [Roskilde] | This work was supported by a grant from the French National Research Agency (ANR-10-BLAN-131301). Research was funded by the Institut National de la Santé et de la Recherche Médicale (INSERM), the Institut Pasteur, the Centre National de la Recherche Scientifique (CNRS). A.S.B. is funded by EMBO (ALTF-1473–2010) and Marie Curie Actions (BMC FP7-PEOPLE-2011-IIF) | ANR-10-BLAN-1313,BMC,Bactéries à multiple chromosomes : liens entre architecture du génome et physiologie cellulaire(2010)
International audience
显示更多 [+] 显示较少 [-]英语. Dam methylates GATC sequences in γ-proteobacteria genomes, regulating several cellular functions including replication. In Vibrio cholerae, which has two chromosomes , Dam is essential for viability, owing to its role in chr2 replication initiation. In this study, we isolated spontaneous mutants of V. cholerae that were able to survive the deletion of dam. In these mutants, homologous recombination and chromosome dimer resolution are essential, unless DNA mismatch repair is inactivated. Furthermore, the initiator of chr2 repli-cation, RctB, is no longer required. We show that, instead, replication of chr2 is insured by spontaneous fusion with chr1 and piggybacking its replication machinery. We report that natural fusion of chr1 and chr2 occurred by two distinct recombination pathways: homologous recombination between repeated IS elements and site-specific recombination between dif sites. Lastly, we observed a preferential fusion of the two chromosomes in their terminus of replication.
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