title: FtsZ polymers bound to lipid bilayers through ZipA form dynamic two dimensional networks.
abstract: Bacteria divide by forming a contractile ring around their midcell region. FtsZ, a cytoskeletal soluble protein structurally related to tubulin, is the main component of this division machinery. It forms filaments that bundle at the inner side of the cytoplasmic membrane. These FtsZ bundles do not attach to bare lipid surfaces. In Escherichia coli they remain near the membrane surface by attaching to the membrane protein ZipA and FtsA. In order to study the structure and dynamics of the ZipA-FtsZ bundles formed on a lipid surface, we have oriented a soluble form of ZipA (sZipA), with its transmembrane domain substituted by a histidine tag, on supported lipid membranes. Atomic force microscopy has been used to visualize the polymers formed on top of this biomimetic surface. In the presence of GTP, when sZipA is present, FtsZ polymers restructure forming higher order structures. The lipid composition of the underlying membrane affects the aggregation kinetics and the shape of the structures formed. On the negatively charged E. coli lipid membranes, filaments condense from initially disperse material to form a network that is more dynamic and flexible than the one formed on phosphatidyl choline bilayers. These FtsZ-ZipA filament bundles are interconnected, retain their capacity to dynamically restructure, to fragment, to anneal and to condense laterally.
authors.affiliation: Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Mateos-Gil
authors.forename: Ileana
authors.initials: I
authors.lastname: Márquez
authors.forename: Pilar
authors.initials: P
authors.lastname: López-Navajas
authors.forename: Mercedes
authors.initials: M
authors.lastname: Jiménez
authors.forename: Miguel
authors.initials: M
authors.lastname: Vicente
authors.forename: Jesús
authors.initials: J
authors.lastname: Mingorance
authors.forename: Germán
authors.initials: G
authors.lastname: Rivas
authors.forename: Marisela
authors.initials: M
authors.lastname: Vélez
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D018625:Microscopy, Atomic Force; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; D008051:Lipid Bilayers; D008565:Membrane Proteins; C103795:ZipA protein, E coli; D006160:Guanosine Triphosphate