Prediction-based protein engineering of domain I of Cry2A entomocidal toxin of Bacillus thuringiensis for the enhancement of toxicity against lepidopteran insects.
Issues relating to sustenance of the usefulness of genetically modified first generation Bt crop plants in the farmer's field are of great concern for crop scientists. Additional biotechnological strategies need to be in place to safeguard the possibility for yield loss of Bt crop by other lepidopteran insects that are insensitive to the Cry1A toxin, and also against the possibility for emergence of resistant insects. In this respect, Cry2A toxin has figured as a prospective candidate to be the second toxin to offer the required protection along with Cry1A. In the present study, the entomocidal potency of Cry2A toxin was enhanced through knowledge-based protein engineering of the toxin molecule. Deletion of 42 amino acid residues from the N-terminal end of the peptide followed by the replacement of Lys residues by nonpolar amino acids in the putative transmembrane region including the introduction of Pro resulted in a 4.1-6.6-fold increase in the toxicity of the peptide against three major lepidopteran insect pests of crop plants.
Mandal
Chandi C
CC
IIT - BREF Biotek, Indian Institute of Technology, Kharagpur-721 302, India.
Gayen
Srimonta
S
Basu
Asitava
A
Ghosh
Kalyan S
KS
Dasgupta
Swagata
S
Maiti
Mrinal K
MK
Sen
Soumitra K
SK
D000595:Amino Acid Sequence; D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry*; D001427:Bacterial Toxins / Q000737:chemistry*; D004731:Endotoxins / Q000737:chemistry*; D017353:Gene Deletion; D006460:Hemolysin Proteins / Q000737:chemistry*; D007814:Larva / Q000378:metabolism; D007915:Lepidoptera; D008239:Lysine / Q000737:chemistry; D008871:Microvilli / Q000378:metabolism; D008969:Molecular Sequence Data; D017354:Point Mutation; D011487:Protein Conformation; D015202:Protein Engineering / Q000379:methods; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D008239:Lysine