Bacillus thuringiensis, insecticidal crystal

Lambert, B., H. Hofte, K. Annys, S. Jansens, P. Soetaert, and M. Peferoen. 1992. Novel Bacillus thuringiensis insecticidal crystal protein with a silent activity against coleopteran larvae. Appl. Environ. Microbiol. 58 2536-2542. 

Noteborn, HPJ, M.E. Bienenmann-Ploum, J.H.J. van den Berg, G.M. Alink, L. Zolla, A. Reynaerts, M. Pensa, and H.A. Kuiper. 1995. Safety assessment of the Bacillus thuringiensis insecticidal crystal protein CRYIA(b) expressed in tomato. In Engel, K.-H., G.R. Takeoka, and R. Teranishi (Eds.), Genetically Modified Foods Safety Issues. American Chemical Society, Washington, DC. p 134-147. 

Tran, L.B., V. Vachon, J-L. Schwartz, and R. Laprade. 2001. Differential effects of pH on the pore-forming properties of Bacillus thuringiensis insecticidal crystal toxins. Appl. Environ. Microbiol. 67 4488-4494. 

The bacterium Bacillus thuringiensis forms an internal crystal that contains a number of insecticidal protein toxins. When eaten by the insect, the crystal dissolves in the midgut, the toxin mixture is released, and the proteins are cleaved into active forms. The toxins bind specifically to midgut cells and assemble a pore that leads to disintegration of the cells, gut paralysis, and death. B. thuringiensis strains have toxins specific for caterpillars, beetles, or flies. They have little or no effect on mammals. 

Bacillus thuringiensis Berliner (commonly known as Bt) is an insecticidal bacterium discovered in the early 20th century. The commercial Bt products are powders containing a mixture of dried spores and crystalline 8-endotoxin, but some contain only the toxin component. Both spores and toxin crystals are produced within the bacterial vegetative cell by Bt (Figure 4.12). Currently, there are six strains that possess specific activity against different insect species as follows ... 

Li JD, Carroll J, Ellar DJ (1991) Crystal structure of insecticidal delta-endotoxin from Bacillus thuringiensis at 2.5 A resolution. In Nature 353 815-821. 

Process of Action of Dipteran-Specific Insecticidal Crystal Proteins from Bacillus thuringiensis subsp. 

Bauer, L. S. 1995. Resistance A threat to the insecticidal crystal proteins of Bacillus thuringiensis. Fla. Entomol. 78 414-443. 

Clairmont, F.R., R.E. Milne, V.T. Pham, M.B. Carriere, and H. Kaplan. 1998. Role of DNA in the activation of the CrylA insecticidal crystal protein from Bacillus thuringiensis. J. Biol. Chem. 273 9292-9296. 

Dankocsik, C., W.P. Donovan, and C.S. Jany. 1990. Activation of a cryptic crystal protein gene of Bacillus thuringiensis subspecies kurstaki by gene fusion and determination of the crystal protein insecticidal specificity. Mol. Microbiol. 4 2087-2094. 

Eschriche, B., N. de Decker, J. Van Rie, S. Jansens, and E. van Kerkhove. 1998. Changes in permeability of brush border membrane vesicles from Spodoptera littoralis midgut induced by insecticidal crystal proteins from Bacillus thuringiensis. Appl. Environ. Microbiol. 64 1563-1565. 

Escriche, B., J. Ferre, and F.J. Silva. 1997. Occurrence of a common binding site in Mamestra brassicae, Phthorimaea operculella, and Spodoptera exigua for the insecticidal crystal proteins CrylA from Bacillus thuringiensis. Insect Biochem. Mol. Biol. 27 651-656. 

Estada, U. and J. Ferre. 1994. Binding of insecticidal crystal proteins of Bacillus thuringiensis to the midgut brush border membrane of the cabbage looper, Trichoplusia ni (Hiibner) (Lepidoptera Noctuidae), and selection for resistance to one of the crystal proteins. Appl. Environ. Microbiol. 60 3840-3846. 

Grochulski, P., L. Masson, S. Borisova, M. Pusztai-Carey, J.L. Schwartz, R. Broussear, and M. Cygler. 1995. Bacillus thuringiensis CrylA(a) insecticidal toxin crystal structure and channel formation. J. Mol. Biol. 

Hofte, H. and H.R. Whiteley. 1989. Insecticidal crystal proteins of Bacillus thuringiensis. Microbiol. Rev. 53 242-255. 

Ellis, R.T., B.A. Stockhoff, L. Stamp, H.E. Schnepf, G.E. Schwab, M. Kunth, J. Russell, G.A. Cardineau, and K.E. Narva. 2002. Novel Bacillus thuringiensis binary insecticidal crystal proteins active on western corn rootwoom, Diabrotica virgifera virgifera LeConte. App. Environ. Microbiol. 68 1137-1145. 

Herman, R.A., P.N. Scherer, D.L. Young, C.A. Mihaliak, T. Meade, A.T. Woodsworth, B.A. Stockhoff, and K.E. Narva. 2002. Binary insecticidal crystal protein from Bacillus thuringiensis, strain PS149B1 effects of individual protein components and mixtures in laboratory bioassays. J. Econ. Entomol. 95 635-639. 

Stelman, S. 2000. Comparison of the Amino Acid Sequence of the Bacillus thuringiensis Strain PS149B1 13.6 kDa and 43.8 kDa Insecticidal Crystal Proteins to Known Protein Allergens Lab Project Number GH-C 5140. Unpublished study prepared by Dow AgroSciences LLC. 188 p. 

Teixeira, D. 2001. Assessment of Chronic Toxicity of Diet Containing Bacillus thuringiensis PS149B1 Insecticidal Crystal Protein To Collembola Folsomia Candida)-. Lab Project Number 12550.6142 011106. Unpublished study prepared by Springborn Laboratories, Inc. 35 p. 

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