Related Experiment Video
Updated: Aug 20, 2025
11:33
Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
6.3K
Spatial and temporal localization of cell wall associated pili in Enterococcus faecalis
Pei Yi Choo1,2, Charles Y Wang1, Michael S VanNieuwenhze3
1Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
Molecular Microbiology
|November 24, 2022
Summary
Enterococcus faecalis biofilm formation relies on sortase-assembled pili (Ebp). New findings show Ebp attach to older cell walls, not new peptidoglycan, challenging established models of bacterial cell wall synthesis.
Area of Science:
- Microbiology
- Cell Biology
- Bacterial Pathogenesis
Background:
- Sortase-assembled pili, like endocarditis and biofilm associated pilus (Ebp), are crucial for Enterococcus faecalis virulence and biofilm formation.
- The established model suggests sortases anchor these pili to peptidoglycan precursors during cell wall synthesis.
Purpose of the Study:
- To investigate the spatiotemporal relationship between Ebp localization and peptidoglycan (PG) synthesis during the Enterococcus faecalis cell cycle.
- To challenge and refine the current model of sortase-assembled pilus biogenesis.
Main Methods:
- Tracking the distribution of Ebp and newly synthesized PG throughout the Enterococcus faecalis cell cycle.
- Utilizing ramoplanin to sequester lipid II and inhibit PG synthesis.
- Observing Ebp deposition in the presence of inhibited PG synthesis.
Main Results:
- Surface-exposed Ebp were found to localize to the older cell hemisphere, distinct from sites of new PG synthesis at the septum.
- Ebp deposition occurred in foci adjacent to the nascent septum on the younger cell hemisphere.
- Inhibition of PG synthesis with ramoplanin did not affect Ebp deposition on the cell surface.
Conclusions:
- Enterococcus faecalis Ebp are anchored to the cell wall independently of new peptidoglycan synthesis.
- A revised model proposes sortase substrates can be deposited onto existing, uncrosslinked cell wall material.
- This finding offers a new perspective on bacterial cell wall biogenesis and pilus assembly.
More Related Videos
10:05Bile Salt-induced Biofilm Formation in Enteric Pathogens: Techniques for Identification and Quantification
Published on: May 6, 2018
12.8K
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
7.1K
Related Concept Videos
01:28Fimbriae, Pili, and Axial Filaments
144
Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...
144
01:29Cytoskeletal Proteins in Bacteria
3.5K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.5K
01:19Formation of Lipopolysaccharides
81
Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin,...
81
01:22Bacterial Cell Wall
222
The bacterial cell wall is an essential structural component that encases the plasma membrane, preserving cellular integrity, determining shape, and protecting against osmotic stress. This rigid yet flexible structure primarily comprises peptidoglycan, a polymer that forms a mesh-like matrix conferring mechanical strength and flexibility.Peptidoglycan Composition and StructurePeptidoglycan, the core of the bacterial cell wall, comprises alternating units of N-acetylglucosamine (NAG) and...
222
01:23Surface Appendages of Archaea
83
Archaeal surface appendages are highly specialized structures essential for environmental adaptation, encompassing roles in adhesion, biofilm formation, and motility. Among these appendages, pili and archaella stand out for their distinct morphologies and functionalities, enabling archaea to thrive in diverse and often extreme environments.Pili: Adhesion and Biofilm FormationPili are filamentous structures assembled from pilin protein subunits, primarily contributing to adhesion and biofilm...
83
01:29Archaeal Cell Wall
114
Archaeal cell walls are structurally and compositionally distinct from their bacterial counterparts, lacking the characteristic peptidoglycan layer found in most bacteria. Instead, archaeal cell walls exhibit remarkable diversity, utilizing materials such as pseudomurein, polysaccharides, and proteins to construct their protective outer layers. This structural flexibility is closely tied to archaea's ecological adaptability.S-Layers: The Common Archaeal Cell WallThe S-layer is the most...
114