A unique cytoplasmic ATPase complex defines the Legionella pneumophila type IV secretion channel.

ABSTRACT: Type IV secretion systems (T4SSs) are complex machines used by bacteria to deliver protein and DNA complexes into target host cells^1-5. Conserved ATPases are essential for T4SS function, but how they coordinate their activities to promote substrate transfer remains poorly understood. Here, we show that the DotB ATPase associates with the Dot-Icm T4SS at the Legionella cell pole through interactions with the DotO ATPase. The structure of the Dot-Icm apparatus was solved in situ by cryo-electron tomography at 3.5 nm resolution and the cytoplasmic complex was solved at 3.0 nm resolution. These structures revealed a cell envelope-spanning channel that connects to the cytoplasmic complex. Further analysis revealed a hexameric assembly of DotO dimers associated with the inner membrane

SUBMITTER: Chetrit D 

PROVIDER: S-EPMC5970066 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature