title: Are the SSB-Interacting Proteins RecO, RecG, PriA and the DnaB-Interacting Protein Rep Bound to Progressing Replication Forks in Escherichia coli?
abstract: In all organisms several enzymes that are needed upon replication impediment are targeted to replication forks by interaction with a replication protein. In most cases these proteins interact with the polymerase clamp or with single-stranded DNA binding proteins (SSB). In Escherichia coli an accessory replicative helicase was also shown to interact with the DnaB replicative helicase. Here we have used cytological observation of Venus fluorescent fusion proteins expressed from their endogenous loci in live E. coli cells to determine whether DNA repair and replication restart proteins that interact with a replication protein travel with replication forks. A custom-made microscope that detects active replisome molecules provided that they are present in at least three copies was used. Neither the recombination proteins RecO and RecG, nor the replication accessory helicase Rep are detected specifically in replicating cells in our assay, indicating that either they are not present at progressing replication forks or they are present in less than three copies. The Venus-PriA fusion protein formed foci even in the absence of replication forks, which prevented us from reaching a conclusion.
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: Esma
authors.initials: E
authors.lastname: Bentchikou
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Chagneau
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Long
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: Mélody
authors.initials: M
authors.lastname: Matelot
authors.affiliation: Laboratoire de Physique Statistique, Département de Physique, UMR 8550 CNRS, Ecole Normale Supérieure, Universités Pierre et Marie Curie and Paris Diderot, Paris, France; IBENS, Département de Biologie, UMR 8542 CNRS, Ecole Normale Supérieure, Paris, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Allemand
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Michel
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D004261:DNA Replication; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D053488:DnaB Helicases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods; D009690:Nucleic Acid Conformation; D011485:Protein Binding
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008164:Luminescent Proteins; C081006:RecO protein, E coli; C476430:SSB protein, E coli; C506744:rep protein, E coli; C054562:yellow fluorescent protein, Bacteria; C071446:RecG protein, E coli; C506743:priA protein, E coli; D004265:DNA Helicases; D053488:DnaB Helicases