March 16, 2023, 11AM

Jean-Luc FERAT, Institut Jacques Monod, Université Paris-Cité

Lieu(x) :      Amphithéâtre Becquerel, Ecole Polytechnique

Contact :    Roxane Lestini
                    roxane.lestini at polytechnique.edu

The reason for replication to be initiated bidirectionally in the 3 domains of life has never been experimentally addressed due to the lack of an appropriate biological system. Using genetic and genomic approaches, we show that bidirectional replication initiation is no longer operated upon depletion of the co-helicase DciA in Vibrio cholerae. Instead, replication is initiated unidirectionally. We found that this unidirectional replication initiation leads to the degradation of nascent DNA strands. Our results suggest that this degradation results from the annealing of the nascent strands free extremities into a free double stranded DNA end. Thus, bidirectional replication initiation is essential in double stranded DNA replication to handcuff nascent DNA ends to prevent their regression and the subsequent pathological degradation of the chromosome

Download: Séminaire FERAT