Insights into the structure and assembly of a bacterial cellulose secretion system
Langue
EN
Article de revue
Ce document a été publié dans
Nature Communications. 2017-12-12, vol. 8, n° 1, p. 2065
Résumé en anglais
Secreted exopolysaccharides present important determinants for bacterial biofilm formation, survival, and virulence. Cellulose secretion typically requires the concerted action of a c-di-GMP-responsive inner membrane ...Lire la suite >
Secreted exopolysaccharides present important determinants for bacterial biofilm formation, survival, and virulence. Cellulose secretion typically requires the concerted action of a c-di-GMP-responsive inner membrane synthase (BcsA), an accessory membrane-anchored protein (BcsB), and several additional Bcs components. Although the BcsAB catalytic duo has been studied in great detail, its interplay with co-expressed subunits remains enigmatic. Here we show that E. coli Bcs proteins partake in a complex protein interaction network. Electron microscopy reveals a stable, megadalton-sized macromolecular assembly, which encompasses most of the inner membrane and cytosolic Bcs components and features a previously unobserved asymmetric architecture. Heterologous reconstitution and mutational analyses point toward a structure-function model, where accessory proteins regulate secretion by affecting both the assembly and stability of the system. Altogether, these results lay the foundation for more comprehensive models of synthase-dependent exopolysaccharide secretion in biofilms and add a sophisticated secretory nanomachine to the diverse bacterial arsenal for virulence and adaptation.< Réduire
Mots clés en anglais
Bacterial secretion
Bacterial structural biology
Biofilms
Electron microscopy
Projet Européen
Molecular and Structural Biology of Bacterial Transformation
Project ANR
Integrative Biology of Emerging Infectious Diseases
Unités de recherche