title: Architecture of the ring formed by the tubulin homologue FtsZ in bacterial cell division.
abstract: Membrane constriction is a prerequisite for cell division. The most common membrane constriction system in prokaryotes is based on the tubulin homologue FtsZ, whose filaments in E. coli are anchored to the membrane by FtsA and enable the formation of the Z-ring and divisome. The precise architecture of the FtsZ ring has remained enigmatic. In this study, we report three-dimensional arrangements of FtsZ and FtsA filaments in C. crescentus and E. coli cells and inside constricting liposomes by means of electron cryomicroscopy and cryotomography. In vivo and in vitro, the Z-ring is composed of a small, single-layered band of filaments parallel to the membrane, creating a continuous ring through lateral filament contacts. Visualisation of the in vitro reconstituted constrictions as well as a complete tracing of the helical paths of the filaments with a molecular model favour a mechanism of FtsZ-based membrane constriction that is likely to be accompanied by filament sliding.
authors.affiliation: Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: Piotr
authors.initials: P
authors.lastname: Szwedziak
authors.affiliation: Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: Tanmay A M
authors.initials: TA
authors.lastname: Bharat
authors.affiliation: Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Tsim
authors.affiliation: Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: Jan
authors.initials: J
authors.lastname: Löwe
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016935:Caulobacter crescentus / Q000378:metabolism / Q000648:ultrastructure*; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure*; D020285:Cryoelectron Microscopy; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism / Q000648:ultrastructure*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D008081:Liposomes / Q000737:chemistry / Q000648:ultrastructure; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C489310:FtsA protein, E coli; C071525:FtsZ protein, Bacteria; D008081:Liposomes
keywords: C. crescentus; E. coli; FtsZ; bacterial cytoskeleton; cell biology; cell division; cytokinesis; electron tomography; infectious disease; microbiology