title: Stabilization of flagellar filaments by HAP2 capping.
abstract: In vivo growth of bacterial flagellar filaments by self-assembly of flagellin is promoted by a capping structure composed of a pentameric assembly of hook associated protein 2 (HAP2). Isolated native filaments with intact HAP2 cap exhibited higher melting temperature (deltaTm = 4 degrees C) and significantly increased resistance against heat-induced depolymerization than non-capped ones. Reconstituted filaments were also stabilized by HAP2 binding, but the obtained filament-HAP2 complexes were less stable than native assemblies. Their fast depolymerization at elevated temperatures and sensitivity to proteolysis indicated that native-like filament-HAP2 complexes are rarely obtained by in vitro reconstitution. A procedure was developed to isolate perfectly capped native filaments to facilitate high-resolution structural analysis.
authors.affiliation: Institute of Enzymology, Hungarian Academy of Sciences, Karolina u. 29, H-1113 Budapest, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Diószeghy
authors.forename: Péter
authors.initials: P
authors.lastname: Závodszky
authors.forename: Keiichi
authors.initials: K
authors.lastname: Namba
authors.forename: Ferenc
authors.initials: F
authors.lastname: Vonderviszt
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron
chemical_list: D001426:Bacterial Proteins; C076733:FlaD protein, Bacteria