Structure, diversity, and evolution of protein toxins from spore-forming entomopathogenic bacteria

Annu Rev Genet. 2003;37:409-33. doi: 10.1146/annurev.genet.37.110801.143042.


Gram-positive spore-forming entomopathogenic bacteria can utilize a large variety of protein toxins to help them invade, infect, and finally kill their hosts, through their action on the insect midgut. These toxins belong to a number of homology groups containing a diversity of protein structures and modes of action. In many cases, the toxins consist of unique folds or novel combinations of domains having known protein folds. Some of the toxins display a similar structure and mode of action to certain toxins of mammalian pathogens, suggesting a common evolutionary origin. Most of these toxins are produced in large amounts during sporulation and have the remarkable feature that they are localized in parasporal crystals. Localization of multiple toxin-encoding genes on plasmids together with mobilizable elements enables bacteria to shuffle their armory of toxins. Recombination between toxin genes and sequence divergence has resulted in a wide range of host specificities.

Publication types

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

MeSH terms

  • Bacillus / chemistry
  • Bacillus / genetics
  • Bacterial Toxins / chemistry*
  • Bacterial Toxins / genetics
  • Biological Evolution*
  • Gram-Positive Endospore-Forming Bacteria / chemistry*
  • Gram-Positive Endospore-Forming Bacteria / genetics
  • Phylogeny
  • Protein Structure, Tertiary
  • Proteins / chemistry
  • Proteins / genetics


  • Bacterial Toxins
  • Proteins