Publications by authors named "S Baconnais"
The replication of the two chromosomes in the pathogenic bacterium Vibrio cholerae is coordinated by the binding of initiator protein RctB to a checkpoint sequence, crtS. Replication of crtS on the primary chromosome (Chr1) triggers replication of the secondary chromosome (Chr2), but the details are poorly understood. Here, we analyze RctB binding patterns in the V.
View Article and Find Full Text PDFHomologous recombination (HR) is a high-fidelity DNA repair pathway that uses a homologous DNA sequence as a template. Recombinase proteins are the central HR players in the three kingdoms of life. RecA/RadA/Rad51 assemble on ssDNA, generated after the processing of double-strand breaks or stalled replication forks into an active and dynamic presynaptic helical nucleofilament.
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- The loading of the bacterial helicase DnaB for genome replication relies on accessory proteins, particularly DciA, which is not well understood.
- Research showed that DciA from Vibrio cholerae forms fluid condensates when interacting with single-stranded DNA, displaying phase separation behavior.
- DnaB is recruited to these condensates while DciA is released, and similar behavior is observed with the helicase loader DnaC from E. coli, suggesting that DciA may help create non-membrane compartments for DNA replication.
DciA is the ancestral bacterial replicative helicase loader, punctually replaced during evolution by the DnaC/I loaders of phage origin. DnaC helps the helicase to load onto DNA by cracking open the hexameric ring, but the mechanism of loading by DciA remains unknown. We demonstrate by electron microscopy, nuclear magnetic resonance (NMR) spectroscopy, and biochemistry experiments that DciA, which folds into a KH-like domain, interacts with not only single-stranded but also double-stranded DNA, in an atypical mode.
View Article and Find Full Text PDFDNA lesions in S phase threaten genome stability. The DNA damage tolerance (DDT) pathways overcome these obstacles and allow completion of DNA synthesis by the use of specialised translesion (TLS) DNA polymerases or through recombination-related processes. However, how these mechanisms coordinate with each other and with bulk replication remains elusive.
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