Biogenesis and structure of a type VI secretion baseplate.
Langue
EN
Article de revue
Ce document a été publié dans
Nature Microbiology. 2018-12-01, vol. 3, n° 12, p. 1404-1416
Résumé en anglais
To support their growth in a competitive environment and cause pathogenesis, bacteria have evolved a broad repertoire of macromolecular machineries to deliver specific effectors and toxins. Among these multiprotein complexes, ...Lire la suite >
To support their growth in a competitive environment and cause pathogenesis, bacteria have evolved a broad repertoire of macromolecular machineries to deliver specific effectors and toxins. Among these multiprotein complexes, the type VI secretion system (T6SS) is a contractile nanomachine that targets both prokaryotic and eukaryotic cells. The T6SS comprises two functional subcomplexes: a bacteriophage-related tail structure anchored to the cell envelope by a membrane complex. As in other contractile injection systems, the tail is composed of an inner tube wrapped by a sheath and built on the baseplate. In the T6SS, the baseplate is not only the tail assembly platform, but also docks the tail to the membrane complex and hence serves as an evolutionary adaptor. Here we define the biogenesis pathway and report the cryo-electron microscopy (cryo-EM) structure of the wedge protein complex of the T6SS from enteroaggregative Escherichia coli (EAEC). Using an integrative approach, we unveil the molecular architecture of the whole T6SS baseplate and its interaction with the tail sheath, offering detailed insights into its biogenesis and function. We discuss architectural and mechanistic similarities but also reveal key differences with the T4 phage and Mu phage baseplates.< Réduire
Mots clés en anglais
Bacteriophages
Cell Membrane
Cryoelectron Microscopy
Escherichia coli
Escherichia coli Proteins
Models
Molecular
Multiprotein Complexes
Protein Conformation
Protein Conformation
alpha-Helical
Protein Interaction Domains and Motifs
Type VI Secretion Systems
Unités de recherche