title: Nucleoid occlusion factor SlmA is a DNA-activated FtsZ polymerization antagonist.
abstract: The tubulin-like FtsZ protein initiates assembly of the bacterial cytokinetic machinery by polymerizing into a ring structure, the Z ring, at the prospective site of division. To block Z-ring formation over the nucleoid and help coordinate cell division with chromosome segregation, Escherichia coli employs the nucleoid-associated division inhibitor, SlmA. Here, we investigate the mechanism by which SlmA regulates FtsZ assembly. We show that SlmA disassembles FtsZ polymers in vitro. In addition, using chromatin immunoprecipitation (ChIP), we identified 24 SlmA-binding sequences (SBSs) on the chromosome. Remarkably, SlmA binding to SBSs dramatically enhanced its ability to interfere with FtsZ polymerization, and ChIP studies indicate that SlmA regulates FtsZ assembly at these sites in vivo. Because of the dynamic and highly organized nature of the chromosome, coupling SlmA activation to specific DNA binding provides a mechanism for the precise spatiotemporal control of its anti-FtsZ activity within the cell.
authors.affiliation: Department of Microbiology and Molecular Genetics and Division of Infectious Diseases, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Hongbaek
authors.initials: H
authors.lastname: Cho
authors.forename: Heather R
authors.initials: HR
authors.lastname: McManus
authors.forename: Simon L
authors.initials: SL
authors.lastname: Dove
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Bernhardt
mesh_terms: D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000648:ultrastructure; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D002876:Chromosomes, Bacterial / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000648:ultrastructure; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D058105:Polymerization; D011485:Protein Binding
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; C502032:SlmA protein, E coli