Cloning and characterization of a novel gene cry9Ec1 encoding lepidopteran-specific parasporal inclusion protein from a Bacillus thuringiensis serovar galleriae strain

Can J Microbiol. 2005 Nov;51(11):988-95. doi: 10.1139/w05-084.

Abstract

A novel delta-endotoxin gene from a lepidopteran-specific Bacillus thuringiensis serovar galleriae strain was cloned, and the full sequence of the cry gene was determined. The cloned 6.5-kb DNA fragment included the full sequence of the cry gene and three open reading frames located upstream of the cry gene. The gene, designated cry9Ec1, encodes a polypeptide of 1154 amino acid residues with a predicted molecular weight of 130 237. The deduced amino acid sequence of the Cry9Ec1 protein had the highest homology (77.7%) with the Cry9Ea1 protein when compared with existing Cry proteins. The expression, in an acrystalliferous B. thuringiensis strain, of the cry9Ec1 gene was high when controlled by the cyt1A2 promoter, leading to the formation of large spherical inclusions. The purified crystals from the recombinant strain were toxic when tested against two lepidopteran species, Bombyx mori and Plutella xylostella. However, the Cry9Ec1 protein gave no toxicity against Spodoptera litura, Spodoptera exigua, Plodia interpunctella, Helicoverpa zea, and Culex pipiens molestus.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacillus thuringiensis / genetics*
  • Bacillus thuringiensis / ultrastructure
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / toxicity
  • Bacterial Toxins / chemistry
  • Bacterial Toxins / genetics*
  • Bacterial Toxins / isolation & purification
  • Bacterial Toxins / toxicity
  • Base Sequence
  • Cloning, Molecular*
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Electrophoresis, Polyacrylamide Gel
  • Endotoxins / chemistry
  • Endotoxins / genetics*
  • Endotoxins / isolation & purification
  • Endotoxins / toxicity
  • Gene Expression
  • Hemolysin Proteins
  • Inclusion Bodies
  • Lepidoptera / drug effects
  • Microscopy, Electron, Transmission
  • Molecular Sequence Data
  • Molecular Weight
  • Open Reading Frames
  • Promoter Regions, Genetic
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid

Substances

  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Bacterial Toxins
  • DNA, Bacterial
  • Endotoxins
  • Hemolysin Proteins
  • insecticidal crystal protein, Bacillus Thuringiensis

Associated data

  • GENBANK/AY550111