Characterization of a novel outer membrane protein targeting pathway in Gram negative bacteria
type: Dataset
description: The Twin Arginine Translocation (Tat) pathway exports folded proteins from the cytoplasm to the periplasm of bacteria. The targeting of the exported proteins to the Tat pathway relies on a specific amino-terminal signal sequence, which is cleaved after exportation. In the phytopathogen Dickeya dadantii the pectin lyase homologue PnlH is exported by the Tat pathway without cleavage of its signal sequence, which anchors PnlH into the outer membrane. In proteobacteria, the vast majority of outer membrane proteins consists of β-barrel proteins and lipoproteins. Targeting of these proteins to the outer membrane relies on two pathways: the periplasmic chaperones SurA, Skp and DegP work together with the β-Barrel-Assembly Machinery (Bam) to target and insert β-barrel proteins into the outer membrane while the Lol pathway targets and insert lipoproteins. In this work, we showed that SurA binds to the hydrophobic PnlH signal sequence during the course of its periplasmic transit. The PnlH signal sequence (41 residues) carries all the information necessary to the targeting of PnlH to the outer membrane. The nature of the information that targets proteins to the Tat system is well charcterized. Thus, we focused on the nature of the information carried by the PnlH signal sequence and that allows its crossing of the periplasm and its insertion in the outer membrane. The deletion of a conserved region of the PnlH signal sequence between residues 28 and 41 strongly affects the targeting of PnlH to the outer membrane. None of the single amino acid substitutions constructed in this region obviously affected the targeting of PnlH, indicating that the information may not reside in the amino acid sequence of the PnlH signal sequence. Consistently, our data suggest that the presence in the PnlH signal sequence of an α helix with a hydrophobic cluster is important for the targeting of PnlH to the outer membrane. This observation is striking since such a structure is considered as an inner…
landing page: https://theses.hal.science/tel-00833222
identifier: NNT: 2012ISAL0126
keyword: adressage
keyword: bacteria
keyword: bacterie
keyword: biosciences
keyword: embrane
keyword: infoeu-reposemanticsdoctoralthesis
keyword: membrane
keyword: membrane-protein
keyword: microbiologie
keyword: microbiology
keyword: proteine-membranaire
keyword: sdvsalife-sciences-q-bioagricultural-sciences
keyword: sequence-signal-tat
keyword: targeting
keyword: tat-signal-sequence
keyword: theses
issued: 2026-05-10T18:19:23.672297
modified: 2026-05-10T18:19:23.672301
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Characterization of a novel outer membrane protein targeting pathway in Gram negative bacteria
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00833222
issued: 2026-05-10T18:19:23.689159
modified: 2026-05-10T18:19:23.652503