A new assembly pathway for the cytokinetic Z ring from a dynamic helical structure in vegetatively growing cells of Bacillus subtilis.
The earliest event in bacterial cell division is the formation of a Z ring, composed of the tubulin-like FtsZ protein, at the division site at midcell. This ring then recruits several other division proteins and together they drive the formation of a division septum between two replicated chromosomes. Here we show that, in addition to forming a cytokinetic ring, FtsZ localizes in a helical-like pattern in vegetatively growing cells of Bacillus subtilis. FtsZ moves rapidly within this helix-like structure. Examination of FtsZ localization in individual live cells undergoing a single cell cycle suggests a new assembly mechanism for Z ring formation that involves a cell cycle-mediated multistep remodelling of FtsZ polymers. Our observations suggest that initially FtsZ localizes in a helical pattern, with movement of FtsZ within this structure occurring along the entire length of the cell. Next, movement of FtsZ in a helical-like pattern is restricted to a central region of the cell. Finally the FtsZ ring forms precisely at midcell. We further show that another division protein, FtsA, shown to interact with FtsZ prior to Z ring formation in B. subtilis, also localizes to similar helical patterns in vegetatively growing cells.
Peters
Phoebe C
PC
Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, NSW 2007, Australia.
Migocki
Margaret D
MD
Thoni
Carola
C
Harry
Elizabeth J
EJ
D001412:Bacillus subtilis / Q000166:cytology* / Q000254:growth & development*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D048749:Cytokinesis; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000378:metabolism*; D050296:Microbial Viability; D008954:Models, Biological; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013171:Spores, Bacterial / Q000166:cytology; D013997:Time Factors
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C065103:FtsA protein, Bacteria; C071525:FtsZ protein, Bacteria; D011993:Recombinant Fusion Proteins