Enhanced toxicity of Bacillus thuringiensis Cry3A δ‐endotoxin in coleopterans by mutagenesis in a receptor binding loop
- 9 May 2000
- journal article
- Published by Wiley in FEBS Letters
- Vol. 473 (2) , 227-232
- https://doi.org/10.1016/s0014-5793(00)01505-2
Abstract
We used site-directed mutagenesis to modify the Bacillus thuringiensis cry3A gene in amino acid residues 350-354. Two mutant toxins, A1 (R(345)A,Y(350)F,Y(351)F) and A2 (R(345)A,DeltaY(350), DeltaY(351)), showed significantly improved toxicity against Tenebrio molitor (yellow mealworm). The mutant toxin A1 was also more potent against both Leptinotarsa decemlineata (Colorado potato beetle) and Chrysomela scripta (cottonwood leaf beetle), while A2 displayed enhanced toxicity only in L. decemlineata. Competitive binding assays of L. decemlineata brush border membrane vesicles (BBMV) revealed that binding affinities for the A1 and A2 mutant toxins were ca. 2.5-fold higher than for the wild-type Cry3 toxin. Similar binding assays with C. scripta BBMV revealed a ca. 5-fold lower dissociation rate for the A1 mutant as compared to that of Cry3A.Keywords
This publication has 52 references indexed in Scilit:
- N-acetylgalactosamine on the putative insect receptor aminopeptidase N is recognised by a site on the domain III lectin-like fold of a Bacillus thuringiensis insecticidal toxinJournal of Molecular Biology, 1999
- Functional Significance of Loops in The Receptor Binding Domain ofBacillus thuringiensisCryIIIA δ-EndotoxinJournal of Molecular Biology, 1996
- Bacillus thuringiensisCrylA(a) Insecticidal Toxin: Crystal Structure and Channel FormationJournal of Molecular Biology, 1995
- Domain-III Exchanges of Bacillus thuringiensisCryIA Toxins Affect Binding to Different Gypsy Moth Midgut ReceptorsBiochemical and Biophysical Research Communications, 1995
- Evolution of Resistance to Bacillus ThuringiensisAnnual Review of Entomology, 1994
- Comparison of a Structural and a Functional EpitopeJournal of Molecular Biology, 1993
- The toxicity of twoBacillus thuringiensis δ-endotoxins to gypsy moth larvae is inversely related to the affinity of binding sites on midgut brush border membranes for the toxinsCellular and Molecular Life Sciences, 1990
- Improved M13 phage cloning vectors and host strains: nucleotide sequences of the M13mpl8 and pUC19 vectorsGene, 1985
- Neue Ergebnisse überBacillus thuringiensis var.tenebrionis unter besonderer Berücksichtigung seiner Wirkung auf den Kartoffelkäfer (Leptinotarsa decemlineata)Journal of Pest Science, 1984
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970