2019 Volume 59 Issue 1 Pages 014-017
Pathogenic bacteria possess specialized secretion systems on their surface. These are nanomachines that aim to transport bacterial virulence factors into host cell cytosol. The type IV secretion systems, which are evolutionarily related to bacterial conjugation systems, have divergent biological functions and are classified into two subgroups, type IVA and type IVB. By using electron microscopy, we first identified the molecular structure of the core complex of the type IVB secretion system from human pathogen Legionella pneumophila. Comparative analyses with the type IVA secretion system revealed the characteristic molecular architecture of this unique nanomachine.
