title: CTXφ Replication Depends on the Histone-Like HU Protein and the UvrD Helicase.
abstract: The Vibrio cholerae bacterium is the agent of cholera. The capacity to produce the cholera toxin, which is responsible for the deadly diarrhea associated with cholera epidemics, is encoded in the genome of a filamentous phage, CTXφ. Rolling-circle replication (RCR) is central to the life cycle of CTXφ because amplification of the phage genome permits its efficient integration into the genome and its packaging into new viral particles. A single phage-encoded HUH endonuclease initiates RCR of the proto-typical filamentous phages of enterobacteriaceae by introducing a nick at a specific position of the double stranded DNA form of the phage genome. The rest of the process is driven by host factors that are either essential or crucial for the replication of the host genome, such as the Rep SF1 helicase. In contrast, we show here that the histone-like HU protein of V. cholerae is necessary for the introduction of a nick by the HUH endonuclease of CTXφ. We further show that CTXφ RCR depends on a SF1 helicase normally implicated in DNA repair, UvrD, rather than Rep. In addition to CTXφ, we show that VGJφ, a representative member of a second family of vibrio integrative filamentous phages, requires UvrD and HU for RCR while TLCφ, a satellite phage, depends on Rep and is independent from HU.
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: Eriel
authors.initials: E
authors.lastname: Martínez
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Paly
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Barre
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D016679:Genome, Viral; D017912:Inovirus / Q000235:genetics* / Q000502:physiology; D014734:Vibrio cholerae / Q000201:enzymology / Q000821:virology; D014779:Virus Replication
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C040330:histone-like protein HU, bacteria; D004265:DNA Helicases