FtsZ-spirals and -arcs determine the shape of the invaginating septa in some mutants of Escherichia coli

• Published in: Molecular microbiology Vol. 22; no. 2; p. 231
• Main Authors: Addinall, S G, Lutkenhaus, J
• Format: Journal Article
• Language: English
• Published: England 01.10.1996
• Subjects: Bacterial Proteins - analysis; Bacterial Proteins - chemistry; Cell Division; Cytoskeletal Proteins; Escherichia coli - chemistry; Escherichia coli - cytology; Escherichia coli - genetics; GTP-Binding Proteins - analysis; GTP-Binding Proteins - chemistry; Microscopy, Electron, Scanning; Microscopy, Fluorescence; Mutation; Phenotype; Temperature
• ISSN: 0950-382X
• DOI: 10.1046/j.1365-2958.1996.00100.x

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.