title: Kinetics of large-scale chromosomal movement during asymmetric cell division in Escherichia coli.
abstract: Coordination between cell division and chromosome replication is essential for a cell to produce viable progeny. In the commonly accepted view, Escherichia coli realize this coordination via the accurate positioning of its cell division apparatus relative to the nucleoids. However, E. coli lacking proper positioning of its cell division planes can still successfully propagate. Here, we characterize how these cells partition their chromosomes into daughters during such asymmetric divisions. Using quantitative time-lapse imaging, we show that DNA translocase, FtsK, can pump as much as 80% (3.7 Mb) of the chromosome between daughters at an average rate of 1700±800 bp/s. Pauses in DNA translocation are rare, and in no occasions did we observe reversals at experimental time scales of a few minutes. The majority of DNA movement occurs at the latest stages of cell division when the cell division protein ZipA has already dissociated from the septum, and the septum has closed to a narrow channel with a diameter much smaller than the resolution limit of the microscope (~250 nm). Our data suggest that the narrow constriction is necessary for effective translocation of DNA by FtsK.
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Jaana
authors.initials: J
authors.lastname: Männik
authors.affiliation: Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, United States of America.
authors.forename: Matthew W
authors.identifier: 0000-0003-4723-8668
authors.initials: MW
authors.lastname: Bailey
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Jordan C
authors.initials: JC
authors.lastname: O'Neill
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America.|Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, United States of America.
authors.forename: Jaan
authors.identifier: 0000-0002-6759-3053
authors.initials: J
authors.lastname: Männik
mesh_terms: D060049:Asymmetric Cell Division / Q000235:genetics*; D002876:Chromosomes, Bacterial / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D059008:Time-Lapse Imaging / Q000379:methods
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C096452:FtsK protein, E coli; D008164:Luminescent Proteins; D008565:Membrane Proteins