Delta endotoxin

delta endotoxin, N-terminal domain
crystal structure of the insecticidal bacterial del endotoxin Cry3Bb1 bacillus thuringiensis
Identifiers
Symbol Endotoxin_N
Pfam PF03945
InterPro IPR005639
SCOP 1dlc
SUPERFAMILY 1dlc
TCDB 1.C.2
delta endotoxin
Structure of insecticidal delta-endotoxin from Bacillus thuringiensis.[1]
Identifiers
Symbol Endotoxin_M
Pfam PF00555
InterPro IPR015790
SCOP 1dlc
SUPERFAMILY 1dlc
TCDB 1.C.2
Bacillus thuringiensis delta-Endotoxin, middle domain
insecticidal crystal protein cry2aa
Identifiers
Symbol Endotoxin_mid
Pfam PF09131
InterPro IPR015214
SCOP 1i5p
SUPERFAMILY 1i5p
delta endotoxin
insecticidal crystal protein cry2aa
Identifiers
Symbol Endotoxin_C
Pfam PF03944
Pfam clan CL0202
InterPro IPR005638
SCOP 1dlc
SUPERFAMILY 1dlc
TCDB 1.C.2
CDD cd04085

Delta endotoxins (δ-endotoxins, also called Cry and Cyt toxins) are pore-forming toxins produced by Bacillus thuringiensis species of bacteria. They are useful for their insecticidal action and are the primary toxin produced by Bt corn.

During spore formation the bacteria produce crystals of this protein. When an insect ingests these proteins, they are activated by proteolytic cleavage. The N-terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. The activated region of the delta toxin is composed of three distinct structural domains: an N-terminal helical bundle domain (InterPro: IPR005639) involved in membrane insertion and pore formation; a beta-sheet central domain involved in receptor binding; and a C-terminal beta-sandwich domain (InterPro: IPR005638) that interacts with the N-terminal domain to form a channel.[2][3][4][5]

References

  1. ↑ Li JD, Carroll J, Ellar DJ (October 1991). "Crystal structure of insecticidal delta-endotoxin from Bacillus thuringiensis at 2.5 A resolution". Nature. 353 (6347): 815–21. doi:10.1038/353815a0. PMID 1658659.
  2. ↑ Cygler M, Borisova S, Grochulski P, Masson L, Pusztai-carey M, Schwartz JL, Brousseau R (1995). "Bacillus thuringiensis CryIA(a) insecticidal toxin: crystal structure and channel formation". J. Mol. Biol. 254 (3): 447–464. doi:10.1006/jmbi.1995.0630. PMID 7490762.
  3. ↑ Ghosh D, Pangborn W, Galitsky N, Cody V, Wojtczak A, Luft JR, English L (2001). "Structure of the insecticidal bacterial delta-endotoxinCry3Bb1 of Bacillus thuringiensis". Acta Crystallogr. D. 57 (8): 1101–1109. doi:10.1107/S0907444901008186. PMID 11468393.
  4. ↑ Grochulski P, Masson L, Borisova S, Pusztai-Carey M, Schwartz JL, Brousseau R, Cygler M (December 1995). "Bacillus thuringiensis CryIA(a) insecticidal toxin: crystal structure and channel formation". J. Mol. Biol. 254 (3): 447–64. doi:10.1006/jmbi.1995.0630. PMID 7490762.
  5. ↑ Galitsky N, Cody V, Wojtczak A, Ghosh D, Luft JR, Pangborn W, English L (August 2001). "Structure of the insecticidal bacterial delta-endotoxin Cry3Bb1 of Bacillus thuringiensis". Acta Crystallogr. D. 57 (Pt 8): 1101–9. doi:10.1107/S0907444901008186. PMID 11468393.

Further reading

  • Bravo, A.; Gill, S. S.; Soberón, M. (2007). "Mode of action of Bacillus thuringiensis Cry and Cyt toxins and their potential for insect control". Toxicon. 49 (4): 423–435. doi:10.1016/j.toxicon.2006.11.022. PMC 1857359. PMID 17198720.
  • Pigott, C. R.; Ellar, D. J. (2007). "Role of Receptors in Bacillus thuringiensis Crystal Toxin Activity" (PDF). Microbiology and Molecular Biology Reviews. 71 (2): 255–281. doi:10.1128/MMBR.00034-06. PMC 1899880. PMID 17554045.
  • Palma, L.; Muñoz, D. (2014). "Bacillus thuringiensis Toxins: An Overview of Their Biocidal Activity". Toxins. 6 (12): 3296–3325. doi:10.3390/toxins6123296. PMC 4280536. PMID 25514092.
This article incorporates text from the public domain Pfam and InterPro: IPR015790


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