Protein function Chaperonin turned insect toxin

• Published in: Nature (London) Vol. 411; no. 6833; p. 44
• Main Authors: Matsuda, Kazuhiko, Yoshida, Naofumi, Oeda, Kenji, Watanabe, Eijiro, Mikami, Toshiyuki, Fukita, Yoshikazu, Nishimura, Keiichiro, Komai, Koichiro
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 03.05.2001
• Subjects: Animals; Binding Sites; Blattellidae; Chaperonin 60 - chemistry; Chaperonin 60 - genetics; Chaperonin 60 - physiology; Cloning, Molecular; Cockroaches; Crystallography, X-Ray; Cytotoxins - chemistry; Cytotoxins - genetics; Cytotoxins - physiology; Cytotoxins - toxicity; E coli; Enterobacter aerogenes - chemistry; Enterobacter aerogenes - physiology; Insect Proteins - chemistry; Insect Proteins - genetics; Insect Proteins - physiology; Insecta - chemistry; Insecta - genetics; Insecta - physiology; Insects; Laboratories; Larva - physiology; Larvae; Mice; Models, Molecular; Myrmeleon; Myrmeleontidae; Polypeptides; Protein Conformation; Proteins; Salivary Proteins and Peptides - chemistry; Salivary Proteins and Peptides - genetics; Salivary Proteins and Peptides - physiology; Symbiosis; Toxicity; Toxins; Japan
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35075148

Antlions are larvae of the Myrmeleontidae family that live on other insects by sucking out the body fluid from their prey, after first paralysing it with a toxin produced by salivary bacteria. Here we show that the paralysing toxin produced by bacterial endosymbionts in the saliva of Myrmeleon bore larvae is a homologue of GroEL, a protective heat-shock protein known as a molecular chaperone. The amino-acid residues critical for this protein's toxicity are located away from the regions essential to its protein-folding activity, indicating that the dual function of this GroEL homologue may benefit both the antlion and the endosymbiont.