Related Experiment Video
Updated: Aug 15, 2025

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
Structure and dynamic association of an assembly platform subcomplex of the bacterial type II secretion system
Régine Dazzoni1, Yuanyuan Li2, Aracelys López-Castilla1
1Institut Pasteur, Université Paris Cité, CNRS UMR3528, Structural Bioinformatics Unit, 75015 Paris, France.
Abstract:
Type II secretion systems (T2SSs) allow diderm bacteria to secrete hydrolytic enzymes, adhesins, or toxins important for growth and virulence. To promote secretion of folded proteins, T2SSs assemble periplasmic filaments called pseudopili or endopili at an inner membrane subcomplex, the assembly platform (AP). Here, we combined biophysical approaches, nuclear magnetic resonance (NMR) and X-ray crystallography, to study the Klebsiella AP components PulL and PulM. We determined the structure and associations of their periplasmic domains and describe the structure of the heterodimer formed by their ferredoxin-like domains. We show how structural complementarity and plasticity favor their association during the secretion process. Cysteine scanning and crosslinking data provided additional constraints to build a structural model of the PulL-PulM assembly in the cellular context. Our structural and functional insights, together with the relative cellular abundance of its components, support the role of AP as a dynamic hub that orchestrates pilus polymerization.
More Related Videos
09:12Applying Live Cell Imaging and Cryo-Electron Tomography to Resolve Spatiotemporal Features of the Legionella pneumophila Dot/Icm Secretion System
Published on: March 10, 2020
10:41Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
Published on: January 4, 2017
Related Concept Videos
Gram-negative Bacterial Protein Secretion Systems
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Formation of Lipopolysaccharides
Cytoskeletal Proteins in Bacteria
Bacterial Translocation and Protein Secretion