Molecular characterization of the type II secretion system of the phytopathogenic bacterium Dickeya dadantii : structural and functional studies of the interaction of OutC and OutD
type: Dataset
description: The type II secretion system (T2SS) is widely exploited by Gram-negative bacteria to secrete diverse virulence factors from the periplasm into the extra-cellular milieu. The phytopathogenic bacterium Dickeya dadanti (ex. Erwinia chrysanthemi) uses this system, named Out, to secrete several cell-wall degrading enzymes that cause soft-rot disease of many plants. The two core components of the Out system, the inner membrane protein OutC and the secretin OutD, which forms a secretion pore in the outer membrane, are involved in secretion specificity. The interaction between OutC and OutD could assure the structural and functional integrity of the secretion system by connecting the two membranes. To understand structure-function relationships between these two components and characterize their interaction sites, we applied an integrative approach involving in vivo cysteine scanning and disulfide cross-linking analysis, truncation analysis of OutC and OutD combined with in vitro GST pull-down, and structural analysis of these proteins and of their interactions by NMR. Our results indicate the presence of at least three interacting sites between the periplasmic regions of OutC and OutD and suggest a β-strand addition mechanism for these interactions. We demonstrated that one site of the HR domain of OutC can interact with two distinct sites of OutD suggesting an alternative mode of their interactions. The presence of exoproteins or/and the inner membrane components of the system OutE-L-M differently alters the affinity of the three OutC-OutD interacting sites. We suggest that successive interactions between these distinct regions of OutC and OutD may have functional importance in switching the secretion machinery between different functional states. To study the mechanism of the targeting and assembly of the secretin OutD into the outer membrane, we exploited the interactions between OutD and two auxiliary proteins, i.e., the inner membrane protein OutB and the outer membra…
identifier: NNT: 2012ISAL0010
issued: 2026-05-14T08:48:03.422244
language: en
modified: 2026-05-14T08:48:03.422249
contact point: Organization
  fn: CCSD
keyword: biosciences
keyword: caracterisation-moleculaire
keyword: infoeu-reposemanticsdoctoralthesis
keyword: metabolism
keyword: metabolisme
keyword: microbiologie
keyword: microbiology
keyword: molecular-characterization
keyword: sdvsalife-sciences-q-bioagricultural-sciences
keyword: secretin
keyword: secretine
keyword: systeme-de-secretion-de-type-ii
keyword: theses
keyword: type-ii-secretion-system
landing page: https://theses.hal.science/tel-00790733

Molecular characterization of the type II secretion system of the phytopathogenic bacterium Dickeya dadantii : structural and functional studies of the interaction of OutC and OutD
type: Distribution
format: HTML
issued: 2026-05-14T08:48:03.455323
modified: 2026-05-14T08:48:03.380725
access URL: https://theses.hal.science/tel-00790733

test_moissonnage_selune
type: Agent