How Bacillus thuringiensis has evolved specific toxins to colonize the insect world.
Bacillus thuringiensis is a bacterium of great agronomic and scientific interest. Together the subspecies of this bacterium colonize and kill a large variety of host insects and even nematodes, but each strain does so with a high degree of specificity. This is mainly determined by the arsenal of crystal proteins that the bacterium produces during sporulation. Here we describe the properties of these toxin proteins and the current knowledge of the basis for their specificity. Assessment of phylogenetic relationships of the three domains of the active toxin and experimental results indicate how sequence divergence in combination with domain swapping by homologous recombination might have caused this extensive range of specificities.
Plant Research International, PO Box 16, 6700 AA, Wageningen, The Netherlands. R.A.deMaagd@plant.wag-ur.nl
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D000818:Animals; D001413:Bacillus thuringiensis / Q000502:physiology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001427:Bacterial Toxins; D004731:Endotoxins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D006460:Hemolysin Proteins; D007313:Insecta / Q000382:microbiology*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011995:Recombination, Genetic / Q000235:genetics; D013171:Spores, Bacterial / Q000502:physiology; D014774:Virulence / Q000235:genetics
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis