title: A replicase clamp-binding dynamin-like protein promotes colocalization of nascent DNA strands and equipartitioning of chromosomes in E. coli.
abstract: In Escherichia coli, bidirectional chromosomal replication is accompanied by the colocalization of sister replication forks. However, the biological significance of this mechanism and the key factors involved are still largely unknown. In this study, we found that a protein, termed CrfC, helps sustain the colocalization of nascent DNA regions of sister replisomes and promote chromosome equipartitioning. CrfC formed homomultimers that bound to multiple molecules of the clamp, a replisome subunit that encircles DNA, and colocalized with nascent DNA regions in a clamp-binding-dependent manner in living cells. CrfC is a dynamin homolog; however, it lacks the typical membrane-binding moiety and instead possesses a clamp-binding motif. Given that clamps remain bound to DNA after Okazaki fragment synthesis, we suggest that CrfC sustains the colocalization of sister replication forks in a unique manner by linking together the clamp-loaded nascent DNA strands, thereby laying the basis for subsequent chromosome equipartitioning.
authors.affiliation: Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Ozaki
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Matsuda
authors.forename: Kenji
authors.initials: K
authors.lastname: Keyamura
authors.forename: Hironori
authors.initials: H
authors.lastname: Kawakami
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Kasho
authors.forename: Komomo
authors.initials: K
authors.lastname: Nagata
authors.forename: Tamami
authors.initials: T
authors.lastname: Masuda
authors.forename: Yukari
authors.initials: Y
authors.lastname: Sakiyama
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Katayama
mesh_terms: D000595:Amino Acid Sequence; D020090:Chromosome Segregation; D002876:Chromosomes, Bacterial; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication / Q000502:physiology; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D034281:Dynamins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D015534:Trans-Activators; C045264:replication initiator protein; D004265:DNA Helicases; D034281:Dynamins