Analysis of Dot/Icm Type IVB Secretion System Subassemblies by Cryoelectron Tomography Reveals Conformational Changes Induced by DotB Binding.

ABSTRACT: Type IV secretion systems (T4SSs) are sophisticated nanomachines used by many bacterial pathogens to translocate protein and DNA substrates across a host cell membrane. Although T4SSs have important roles in promoting bacterial infections, little is known about the biogenesis of the apparatus and the mechanism of substrate transfer. Here, high-throughput cryoelectron tomography (cryo-ET) was used to visualize Legionella pneumophila T4SSs (also known as Dot/Icm secretion machines) in both the whole-cell context and at the cell pole. These data revealed the distribution patterns of individual Dot/Icm machines in the bacterial cell and identified five distinct subassembled intermediates. High-resolution in situ structures of the Dot/Icm machine derived from subtomogram averaging

SUBMITTER: Park D 

PROVIDER: S-EPMC7029142 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature