Stabilization of flagellar filaments by HAP2 capping.
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.
Diószeghy
Zoltán
Z
Institute of Enzymology, Hungarian Academy of Sciences, Karolina u. 29, H-1113 Budapest, Hungary.
Závodszky
Péter
P
Namba
Keiichi
K
Vonderviszt
Ferenc
F
D001426:Bacterial Proteins / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron
D001426:Bacterial Proteins; C076733:FlaD protein, Bacteria