title: Novel coiled-coil cell division factor ZapB stimulates Z ring assembly and cell division.
abstract: Formation of the Z ring is the first known event in bacterial cell division. However, it is not yet known how the assembly and contraction of the Z ring are regulated. Here, we identify a novel cell division factor ZapB in Escherichia coli that simultaneously stimulates Z ring assembly and cell division. Deletion of zapB resulted in delayed cell division and the formation of ectopic Z rings and spirals, whereas overexpression of ZapB resulted in nucleoid condensation and aberrant cell divisions. Localization of ZapB to the divisome depended on FtsZ but not FtsA, ZipA or FtsI, and ZapB interacted with FtsZ in a bacterial two-hybrid analysis. The simultaneous inactivation of FtsA and ZipA prevented Z ring assembly and ZapB localization. Time lapse microscopy showed that ZapB-GFP is present at mid-cell in a pattern very similar to that of FtsZ. Cells carrying a zapB deletion and the ftsZ84(ts) allele exhibited a synthetic sick phenotype and aberrant cell divisions. The crystal structure showed that ZapB exists as a dimer that is 100% coiled-coil. In vitro, ZapB self-assembled into long filaments and bundles. These results raise the possibility that ZapB stimulates Z ring formation directly via its capacity to self-assemble into larger structures.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Gitte
authors.initials: G
authors.lastname: Ebersbach
authors.forename: Elisa
authors.initials: E
authors.lastname: Galli
authors.forename: Jakob
authors.initials: J
authors.lastname: Møller-Jensen
authors.forename: Jan
authors.initials: J
authors.lastname: Löwe
authors.forename: Kenn
authors.initials: K
authors.lastname: Gerdes
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D046915:Penicillin-Binding Proteins / Q000378:metabolism; D046928:Peptidoglycan Glycosyltransferase / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D020798:Two-Hybrid System Techniques
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C489310:FtsA protein, E coli; C478704:FtsI protein, E coli; C071525:FtsZ protein, Bacteria; D046915:Penicillin-Binding Proteins; D011993:Recombinant Fusion Proteins; C103795:ZipA protein, E coli; D049452:Green Fluorescent Proteins; D046928:Peptidoglycan Glycosyltransferase