Implication of RuvABC and RecG in homologous recombination in Streptomyces ambofaciens
Résumé
Most bacterial organisms rely on homologous recombination to repair DNA double-strand breaks and for the post-replicative repair of DNA single-strand gaps. Homologous recombination can be divided into three steps: (i) a pre-synaptic step in which the DNA 3'-OH ends are processed, (ii) a recA-dependent synaptic step allowing the invasion of an intact copy and the formation of Holliday junctions, and (iii) a post synaptic step consisting of migration and resolution of these junctions.
Currently, little is known about factors involved in homologous recombination, especially for the post-synaptic step. In Escherichia coli, branch migration and resolution are performed by the RuvABC complex, but could also rely on the RecG helicase in a redundant manner. In this study, we show that recG and ruvABC are well-conserved among Streptomyces. AruvABC, ArecG and AruvABC ArecG mutant strains were constructed. A ruvABC A recG is only slightly affected by exposure to DNA damage (UV). We also show that conjugational recombination decreases in the absence of RuvABC and RecG, but that intrachromosomal recombination is not affected.
These data suggest that RuvABC and RecG are indeed involved in homologous recombination in Streptomyces ambofaciens and that alternative factors are able to take over Holliday junction in Streptomyces.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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