Cry - Pesticidal crystal proteins

Pore-forming Toxins

Members of this family are proteins/peptides, synthesized by one cell and secreted for insertion into the membrane of another cell where they form transmembrane pores. Pore-forming toxins (PFTs) are the most common bacterial cytotoxic proteins and are required for virulence in a large number of important pathogens.

Over 100 subgroups belong to the "Pore-forming Toxins" family, including amongst others:

  • The α-Hemolysin Channel-forming Toxin (αHL) Family
  • The Aerolysin Channel-forming Toxin (Aerolysin) Family
  • The Botulinum and Tetanus Toxin (BTT) Family
  • The Pertussis Toxin (PTX) Family
  • The Crystal Protein (Cry) Family

Cry Proteins Background Information


Pesticidal crystal "Cry" proteins, also called Insecticidal delta-endotoxin, are a product of Bacillus thuringiensis. During sporulation, the bacillus produces these pore-forming toxins which have insecticidal action. This has led to their use as insecticides, and more recently to genetically modified crops using Bt genes.
When insects ingest toxin crystals, their alkaline digestive tracts denature the insoluble crystals, making them soluble and thus amenable to being cut with proteases found in the insect gut, which liberate the toxin from the crystal. The Cry toxin is then inserted into the insect gut cell membrane, paralyzing the digestive tract and forming a pore.

Data Sheet:

cry1Aa, cry2Aa, cry3Aa and several more

Proteins (3 examples):
UniProt P0A379, UniProt P0A377, UniProt P0A367

Function/ Application:
Promotes colloidosmotic lysis by binding to the midgut epithelial cells of many lepidopteran larvae.

Bilayer Recordings on the Orbit Instrument family

Reviews and Links


2017 - Validation of ADAM10 metalloprotease as a Bacillus thuringiensis Cry3Aa toxin functional receptor in Colorado potato beetle (Leptinotarsa decemlineata)

Icon Orbit  Orbit 16 publication in Insect Molecular Biology (2017)

Ruiz-Arroyo V.M., García-Robles I., Ochoa-Campuzano C., Goig G.A., Zaitseva E., Baaken G., Martínez-Ramírez A.C., Rausell C., Real M.D.

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