Trapping of a spiral-like intermediate of the bacterial cytokinetic protein FtsZ.
The earliest stage in bacterial cell division is the formation of a ring, composed of the tubulin-like protein FtsZ, at the division site. Tight spatial and temporal regulation of Z-ring formation is required to ensure that division occurs precisely at midcell between two replicated chromosomes. However, the mechanism of Z-ring formation and its regulation in vivo remain unresolved. Here we identify the defect of an interesting temperature-sensitive ftsZ mutant (ts1) of Bacillus subtilis. At the nonpermissive temperature, the mutant protein, FtsZ(Ts1), assembles into spiral-like structures between chromosomes. When shifted back down to the permissive temperature, functional Z rings form and division resumes. Our observations support a model in which Z-ring formation at the division site arises from reorganization of a long cytoskeletal spiral form of FtsZ and suggest that the FtsZ(Ts1) protein is captured as a shorter spiral-forming intermediate that is unable to complete this reorganization step. The ts1 mutant is likely to be very valuable in revealing how FtsZ assembles into a ring and how this occurs precisely at the division site.
Michie
Katherine A
KA
Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, NSW 2007, Australia.
Monahan
Leigh G
LG
Beech
Peter L
PL
Harry
Elizabeth J
EJ
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D002455:Cell Division; D002876:Chromosomes, Bacterial / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D003599:Cytoskeleton / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017354:Point Mutation; D016415:Sequence Alignment; D013696:Temperature
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria