title: ZapA and ZapB form an FtsZ-independent structure at midcell.
abstract: Cell division in Escherichia coli begins with the polymerization of FtsZ into a ring-like structure, the Z-ring, at midcell. All other division proteins are thought to require the Z-ring for recruitment to the future division site. Here, it is reported that the Z-ring associated proteins ZapA and ZapB form FtsZ-independent structures at midcell. Upon Z-ring disruption by the FtsZ polymerization antagonist SulA, ZapA remained at midcell as a cloud-like accumulation. Using ZapA(N60Y), a variant defective for interaction with FtsZ, it was established that these ZapA structures form without a connection to the Z-ring. Furthermore, midcell accumulations of GFP-ZapA(N60Y) often preceded Z-rings at midcell and required ZapB to assemble, suggesting that ZapB polymers form the foundation of these structures. In the absence of MatP, a DNA-binding protein that links ZapB to the chromosomal terminus region, cloud-like ZapA structures still formed but failed to track with the chromosome terminus and did not consistently precede FtsZ at midcell. Taken together, the results suggest that FtsZ-independent structures of ZapA-ZapB provide additional positional cues for Z-ring formation and may help coordinate its assembly with chromosome replication and segregation.
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.|Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
authors.forename: Jackson A
authors.initials: JA
authors.lastname: Buss
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Nick T
authors.initials: NT
authors.lastname: Peters
authors.affiliation: Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Thomas G
authors.identifier: 0000-0003-3566-7756
authors.initials: TG
authors.lastname: Bernhardt
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D058105:Polymerization; D011485:Protein Binding
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C520744:ZapA protein, E coli; C553097:ZapB protein, E coli