FtsZ-spirals and -arcs determine the shape of the invaginating septa in some mutants of Escherichia coli.
The essential cell division protein FtsZ forms a dynamic ring structure at the future division site. This Z-ring contracts during cell division while maintaining a position at the leading edge of the invaginating septum. Using immunofluorescence microscopy we have characterized two situations in which non-ring FtsZ structures are formed. In ftsZ26 (temperature sensitive, Ts) mutant cells, FtsZ-spirals are formed and lead to formation of spirally invaginating septa, which in turn cause morphological abnormalities. In rodAoul mutant cells, which grow as spheres instead of rods, FtsZ-arcs are formed where asymmetric septal invaginations are initiated. The FtsZ-arcs later mature into complete FtsZ-rings. Our data show that Z-spirals and Z-arcs can contract and that in doing so, they determine the shape of the invaginating septa. These results also strongly suggest that in normal cell division, FtsZ is positioned to a single nucleation site on the inner membrane, from which it polymerizes bidirectionally around the cell circumference to form the Z-ring.
Addinall
S G
SG
Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City 66160, USA.
Lutkenhaus
J
J
D001426:Bacterial Proteins / Q000032:analysis* / Q000737:chemistry; D002455:Cell Division; D003598:Cytoskeletal Proteins; D004926:Escherichia coli / Q000737:chemistry / Q000166:cytology* / Q000235:genetics; D019204:GTP-Binding Proteins / Q000032:analysis* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D009154:Mutation; D010641:Phenotype; D013696:Temperature
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D019204:GTP-Binding Proteins