title: Complex polar machinery required for proper chromosome segregation in vegetative and sporulating cells of Bacillus subtilis.
abstract: Chromosome segregation is an essential process of cell multiplication. In prokaryotes, segregation starts with the newly replicated sister origins of replication, oriCs, which move apart to defined positions in the cell. We have developed a genetic screen to identify mutants defective in placement of oriC during spore development in the Gram-positive bacterium Bacillus subtilis. In addition to the previously identified proteins Soj and DivIVA, our screen identified several new factors involved in polar recruitment of oriC: a reported regulator of competence ComN, and the regulators of division site selection MinD and MinJ. Previous work implicated Soj as an important regulator of oriC positioning in the cell. Our results suggest a model in which the DivIVA-interacting proteins ComN and MinJ recruit MinD to the cell pole, and that these proteins work upstream of Soj to enable oriC placement. We show that these proteins form a polar complex, which acts in parallel with but distinct from the sporulation-specific RacA pathway of oriC placement, and also functions during vegetative growth. Our study further shows that MinD has two distinct cell cycle roles, in cell division and chromosome segregation, and highlights that cell probably use multiple parallel mechanisms to ensure accurate chromosome segregation.
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.|Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
authors.forename: Tomas G
authors.initials: TG
authors.lastname: Kloosterman
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.|Lek Pharmaceuticals d.d., Menges, Slovenia.
authors.forename: Rok
authors.initials: R
authors.lastname: Lenarcic
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Clare R
authors.initials: CR
authors.lastname: Willis
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: David M
authors.initials: DM
authors.lastname: Roberts
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.|Department of Cell Biology & Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Leendert W
authors.initials: LW
authors.lastname: Hamoen
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Jeff
authors.initials: J
authors.lastname: Errington
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Ling J
authors.initials: LJ
authors.lastname: Wu
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D016764:Cell Polarity / Q000235:genetics* / Q000502:physiology; D020090:Chromosome Segregation / Q000235:genetics*; D002876:Chromosomes, Bacterial / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D009154:Mutation; D018741:Replication Origin / Q000235:genetics / Q000502:physiology; D013171:Spores, Bacterial / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins