title: FtsZ condensates: an in vitro electron microscopy study.
abstract: In vivo cell division protein FtsZ from E. coli forms rings and spirals which have only been observed by low resolution light microscopy. We show that these suprastructures are likely formed by molecular crowding which is a predominant factor in prokaryotic cells and enhances the weak lateral bonds between proto-filaments. Although FtsZ assembles into single proto-filaments in dilute aqueous buffer, with crowding agents above a critical concentration, it forms polymorphic supramolecular structures including rings and toroids (with multiple protofilaments) about 200 nm in diameter, similar in appearance to DNA toroids, and helices with pitches of several hundred nm as well as long, linear bundles. Helices resemble those observed in vivo, whereas the rings and toroids may represent a novel energy minimized state of FtsZ, at a later stage of Z-ring constriction. We shed light on the molecular arrangement of FtsZ filaments within these suprastructures using high resolution electron microscopy.
authors.affiliation: ERATO Actin Filament Dynamics Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan. dpopp@spring8.or.jp
authors.forename: David
authors.initials: D
authors.lastname: Popp
authors.forename: Mitsusada
authors.initials: M
authors.lastname: Iwasa
authors.forename: Akihiro
authors.initials: A
authors.lastname: Narita
authors.forename: Harold P
authors.initials: HP
authors.lastname: Erickson
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Maéda
mesh_terms: D001426:Bacterial Proteins / Q000648:ultrastructure*; D002412:Cations / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000648:ultrastructure*; D004492:Edetic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000648:ultrastructure*; D008854:Microscopy, Electron; D012964:Sodium / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D002412:Cations; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D004492:Edetic Acid; D012964:Sodium