A widespread accessory protein family diversifies the effector repertoire of the type VI secretion system spike.

ABSTRACT: Type VI secretion systems (T6SSs) are macromolecular assemblies that deliver toxic effector proteins between adjacent bacteria. These effectors span a wide range of protein families that all lack canonical signal sequences that would target them for export. Consequently, it remains incompletely understood how conserved structural components of the T6SS apparatus recognize a diverse repertoire of effectors. Here, we characterize a widespread family of adaptor proteins, containing the domain of unknown function DUF4123, that enable the recognition and export of evolutionarily unrelated effectors. By examining two nearly identical paralogs of the conserved T6SS spike protein, VgrG, we demonstrate that each spike protein exports a structurally unique effector. We further show that the recruitm

SUBMITTER: Colautti J 

PROVIDER: S-EPMC11582642 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature