Structural interactions define assembly adapter function of a type II secretion system pseudopilin - DynAMic - Dynamique des génomes et adaptation microbienne Accéder directement au contenu
Article Dans Une Revue Structure Année : 2021

Structural interactions define assembly adapter function of a type II secretion system pseudopilin

Résumé

The type IV filament superfamily comprises widespread membrane-associated polymers in prokaryotes. The type II secretion system (T2SS), a virulence pathway in many pathogens, belongs to this superfamily. A knowledge gap in understanding of the T2SS is the molecular role of a small “pseudopilin” protein. Using multiple biophysical techniques, we have deciphered how this missing component of the Xcp T2SS architecture is structurally integrated, and thereby unlocked its function. We demonstrate that low-abundance XcpH is the adapter that bridges a trimeric initiating tip complex, XcpIJK, with a periplasmic filament of XcpG subunits. Each pseudopilin protein caps an XcpG protofilament in an overall pseudopilus compatible with dimensions of the periplasm and the outer membrane-spanning secretin through which substrates pass. Unexpectedly, to fulfill its adapter function, the XcpH N-terminal helix must be unwound, a property shared with XcpG subunits. We provide an experimentally validated three-dimensional structural model of a complete type IV filament.
Fichier principal
Vignette du fichier
xcpuvwx_113020_textfigs_opt.pdf (19.24 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03367306 , version 1 (01-04-2022)

Identifiants

Citer

Cristian Escobar, Badreddine Douzi, Geneviève Ball, Brice Barbat, Sebastien Alphonse, et al.. Structural interactions define assembly adapter function of a type II secretion system pseudopilin. Structure, 2021, 29 (10), pp.1116-1127.e8. ⟨10.1016/j.str.2021.05.015⟩. ⟨hal-03367306⟩
167 Consultations
23 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More