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Appl Environ Microbiol. 1996 January; 62(1): 80–86.
PMCID: PMC167775

A Bacillus thuringiensis insecticidal crystal protein with a high activity against members of the family Noctuidae.


The full characterization of a novel insecticidal crystal protein, named Cry9Ca1 according to the revised nomenclature for Cry proteins, from Bacillus thuringiensis serovar tolworthi is reported. The crystal protein has 1,157 amino acids and a molecular mass of 129.8 kDa. It has the typical features of the Lepidoptera-active crystal proteins such as five conserved sequence blocks. Also, it is truncated upon trypsin digestion to a toxic fragment of 68.7 kDa by removal of 43 amino acids at the N terminus and the complete C-terminal half after conserved sequence block 5. The 68.7-kDa fragment is further degraded to a nontoxic 55-kDa fragment. The crystal protein has a fairly broad spectrum of activity against lepidopteran insects, including members of the families Pyralidae, Plutellidae, Sphingidae, and Noctuidae. A 50% lethal concentration of less than 100 ng/cm2 of diet agar was found for diamondback moth, European corn borer, cotton bollworm, and beet armyworm. It is the first insecticidal crystal protein with activity against cutworms. No activity was observed against some beetles, such as Colorado potato beetle. The protein recognizes a receptor different from that recognized by Cry1Ab5 in Ostrinia nubilalis and Plutella xylostella. In Spodoptera exigua and P. xylostella, it binds to a receptor which is also recognized by Cry1Cax but with a lower affinity. In these insects, Cry1Cax probably binds with a higher affinity to an additional receptor which is not recognized by Cry9Ca1. Elimination of a trypsin cleavage site which is responsible for the degradation to a nontoxic fragment did result in protease resistance but not in increased toxicity against O. nubilalis.

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Selected References

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  • Arantes O, Lereclus D. Construction of cloning vectors for Bacillus thuringiensis. Gene. 1991 Dec 1;108(1):115–119. [PubMed]
  • Bosch D, Schipper B, van der Kleij H, de Maagd RA, Stiekema WJ. Recombinant Bacillus thuringiensis crystal proteins with new properties: possibilities for resistance management. Biotechnology (N Y) 1994 Sep;12(9):915–918. [PubMed]
  • Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. [PubMed]
  • Brinkmann U, Pai LH, FitzGerald DJ, Pastan I. Alteration of a protease-sensitive region of Pseudomonas exotoxin prolongs its survival in the circulation of mice. Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):3065–3069. [PubMed]
  • Ho SN, Hunt HD, Horton RM, Pullen JK, Pease LR. Site-directed mutagenesis by overlap extension using the polymerase chain reaction. Gene. 1989 Apr 15;77(1):51–59. [PubMed]
  • Höfte H, Whiteley HR. Insecticidal crystal proteins of Bacillus thuringiensis. Microbiol Rev. 1989 Jun;53(2):242–255. [PMC free article] [PubMed]
  • Maxam AM, Gilbert W. Sequencing end-labeled DNA with base-specific chemical cleavages. Methods Enzymol. 1980;65(1):499–560. [PubMed]
  • Travers RS, Martin PA, Reichelderfer CF. Selective Process for Efficient Isolation of Soil Bacillus spp. Appl Environ Microbiol. 1987 Jun;53(6):1263–1266. [PMC free article] [PubMed]
  • Van Rie J, Jansens S, Höfte H, Degheele D, Van Mellaert H. Receptors on the brush border membrane of the insect midgut as determinants of the specificity of Bacillus thuringiensis delta-endotoxins. Appl Environ Microbiol. 1990 May;56(5):1378–1385. [PMC free article] [PubMed]
  • Wu D, Cao XL, Bai YY, Aronson AI. Sequence of an operon containing a novel delta-endotoxin gene from Bacillus thuringiensis. FEMS Microbiol Lett. 1991 Jun 1;65(1):31–35. [PubMed]
  • Yanisch-Perron C, Vieira J, Messing J. Improved M13 phage cloning vectors and host strains: nucleotide sequences of the M13mp18 and pUC19 vectors. Gene. 1985;33(1):103–119. [PubMed]

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