Cryo-EM structure of the QseG-QseE complex reveals an accessory protein-driven two-component system activation mechanism.

ABSTRACT: The two-component system (TCS) enables bacteria to sense and respond to environmental changes through histidine kinase-mediated signaling cascades. Although the core components of TCSs have been extensively studied, the molecular basis of accessory proteins in modulating histidine kinase activity remains poorly understood. Here, we report that the outer membrane lipoprotein QseG functions as an accessory protein that directly binds to and activates the histidine kinase QseE via its C-terminal domain. Cryo-electron microscopy (Cryo-EM) structural analysis of the QseG-QseE complex reveals a novel yet conserved interaction mode between an accessory lipoprotein and a histidine kinase, which bridges the outer membrane to cytoplasm. Furthermore, systematic truncation assays and photo-crosslinkin

SUBMITTER: Gong P 

PROVIDER: S-EPMC12691602 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature