Related Experiment Video
Updated: Jul 17, 2026

Creating and Applying a Reference to Facilitate the Discussion and Classification of Proteins in a Diverse Group
Published on: August 16, 2017
Structural analysis of cassiicolin, a host-selective protein toxin from Corynespora cassiicola
Philippe Barthe1, Valérie Pujade-Renaud, Frédéric Breton
1Centre de Biochimie Structurale, UMR 5048 CNRS/UM1-UMR 554 Inserm/UM1, 29 rue de Navacelles, 34090 Montpellier Cedex, France.
Cassiicolin, a toxin from Corynespora cassiicola fungus, causes rubber tree leaf fall. Its unique 3D structure, determined by NMR, reveals a novel protein fold similar to insect inhibitors, aiding mechanism of action studies.
Area of Science:
- Plant Pathology
- Mycology
- Structural Biology
Background:
- Corynespora leaf fall (CLF) disease, caused by Corynesporacassiicola, significantly impacts rubber tree (Hevea brasiliensis) production.
- Cassiicolin is a key host-selective toxin (HST) produced by C. cassiicola responsible for CLF disease.
Purpose of the Study:
- To elucidate the structural characteristics of purified cassiicolin.
- To understand the mechanism of cellular damage and host selectivity induced by cassiicolin.
- To provide a structural basis for future studies on cassiicolin's mode of action.
Main Methods:
- Purification of cassiicolin.
- Electron microscopy to observe cellular damage.
- Nuclear Magnetic Resonance (NMR) spectroscopy for solution structure determination.
- Simulated annealing calculations for disulfide pairing and structural modeling.
Main Results:
- Cassiicolin, a 27-residue O-glycosylated protein, induces cellular damage identical to fungal infection and exhibits host selectivity.
- The solution structure reveals an original prolate ellipsoid shape with a right-handed twisted, antiparallel beta-sheet stabilized by three disulfide bonds.
- Cassiicolin's fold resembles locust protease inhibitors but lacks sequence homology and key functional motifs, suggesting a conserved structural scaffold.
Conclusions:
- Cassiicolin's unique structure provides insights into its role in CLF disease pathogenesis.
- The identified structural motif may represent a versatile scaffold utilized across different biological functions and phyla.
- Knowledge of cassiicolin's 3D structure facilitates future investigations into its mechanism of action via site-directed mutagenesis.
More Related Videos
09:03A Simple Fluorescence-based Reporter Assay to Identify Cellular Components Required for Ricin Toxin A Chain (RTA) Trafficking in Yeast
Published on: December 15, 2017
07:40Identification of Host Pathways Targeted by Bacterial Effector Proteins using Yeast Toxicity and Suppressor Screens
Published on: October 25, 2019
Related Concept Videos
Bacterial Toxins
Caspases
Diphtheria
Types of Toxins
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
Botulism
CRISPR and crRNAs
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...