title: Intracellular locations of replication proteins and the origin of replication during chromosome duplication in the slowly growing human pathogen Helicobacter pylori.
abstract: We followed the position of the replication complex in the pathogenic bacterium Helicobacter pylori using antibodies raised against the single-stranded DNA binding protein (HpSSB) and the replicative helicase (HpDnaB). The position of the replication origin, oriC, was also localized in growing cells by fluorescence in situ hybridization (FISH) with fluorescence-labeled DNA sequences adjacent to the origin. The replisome assembled at oriC near one of the cell poles, and the two forks moved together toward the cell center as replication progressed in the growing cell. Termination and resolution of the forks occurred near midcell, on one side of the septal membrane. The duplicated copies of oriC did not separate until late in elongation, when the daughter chromosomes segregated into bilobed nucleoids, suggesting sister chromatid cohesion at or near the oriC region. Components of the replication machinery, viz., HpDnaB and HpDnaG (DNA primase), were found associated with the cell membrane. A model for the assembly and location of the H. pylori replication machinery during chromosomal duplication is presented.
authors.affiliation: Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.
authors.forename: Atul
authors.initials: A
authors.lastname: Sharma
authors.forename: Mohammad
authors.initials: M
authors.lastname: Kamran
authors.forename: Vijay
authors.initials: V
authors.lastname: Verma
authors.forename: Santanu
authors.initials: S
authors.lastname: Dasgupta
authors.forename: Suman Kumar
authors.initials: SK
authors.lastname: Dhar
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D004261:DNA Replication / Q000502:physiology*; D004269:DNA, Bacterial / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D016480:Helicobacter pylori / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins