Crystal structure of Cry51Aa1: A potential novel insecticidal aerolysin-type β-pore-forming toxin from Bacillus thuringiensis

Biochem Biophys Res Commun. 2015 Jul 3;462(3):184-9. doi: 10.1016/j.bbrc.2015.04.068. Epub 2015 May 7.


The structures of several Bacillus thuringiensis (Bt) insecticidal crystal proteins have been determined by crystallographic methods and a close relationship has been explicated between specific toxicities and conserved three-dimensional architectures. In this study, as a representative of the coleopteran- and hemipteran-specific Cry51A group, the complete structure of Cry51Aa1 protoxin has been determined by X-ray crystallography at 1.65 Å resolution. This is the first report of a coleopteran-active Bt insecticidal toxin with high structural similarity to the aerolysin-type β-pore forming toxins (β-PFTs). Moreover, study of featured residues and structural elements reveal their possible roles in receptor binding and pore formation events. This study provides new insights into the action of aerolysin-type β-PFTs from a structural perspective, and could be useful for the control of coleopteran and hemipteran insect pests in agricultures.

Keywords: Bacillus thuringiensis; Crystal structure; Insecticidal; Pore-forming toxin.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacillus thuringiensis / chemistry*
  • Bacillus thuringiensis / genetics
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Toxins / chemistry*
  • Bacterial Toxins / genetics
  • Coleoptera
  • Crystallography, X-Ray
  • Endotoxins / chemistry*
  • Endotoxins / genetics
  • Hemolysin Proteins / chemistry*
  • Hemolysin Proteins / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Pest Control, Biological
  • Pore Forming Cytotoxic Proteins / chemistry*
  • Pore Forming Cytotoxic Proteins / genetics
  • Protein Conformation
  • Protein Interaction Domains and Motifs
  • Protein Structure, Quaternary
  • Sequence Homology, Amino Acid


  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Bacterial Toxins
  • Endotoxins
  • Hemolysin Proteins
  • Pore Forming Cytotoxic Proteins
  • insecticidal crystal protein, Bacillus Thuringiensis
  • aerolysin