Cloning and study of the expression of a novel cry1Ia-type gene from Bacillus thuringiensis subsp. kurstaki.
OBJECTIVE
Cloning and expression of a new cry1Ia-type gene of Bacillus thuringiensis.


RESULTS
PCR amplification, using gene cry1I-specific primers revealed the presence of such a gene in the strain BNS3 of Bacillus thuringiensis subsp. kurstaki. The cloning and sequencing from BNS3 of the cry1Ia-type gene, called crybns3-3, showed an open reading frame of 2160-bp, encoding a protein of 719 amino acid residues. Both nucleotide and amino acid sequences similarity analysis revealed that the crybns3-3 is a new cry1Ia-type gene, presenting several differences from the cry1Ia-type genes. The study of the expression of crybns3-3 by Northern blot and RT-PCR showed that it was transcribed. The expression of crybns3-3 under the control of BtI and BtII promoters revealed that Crybns3-3 would co-crystallize with the endogenous delta-endotoxins.


CONCLUSIONS
crybns3-3 is a novel cry1Ia gene isolated from B. thuringiensis subsp. kurstaki strain BNS3.


CONCLUSIONS
The characteristics of crybns3-3 indicate that it is a new cry1Ia-type gene. Amino acid residue substitutions presented in Crybns3-3 could be exploited for both toxicity and specificity studies. Crybns3-3 would interact and co-crystallize at least partially with the endogenous delta-endotoxins of BNS3, and then participate in the formation of the parasporal crystal inclusions.
Tounsi
S
S
Laboratoire des Biopesticides, Centre de Biotechnologie de Sfax, Sfax, Tunisia. samir.jaoua@cbs.rnrt.tn
Zouari
N
N
Jaoua
S
S
D001413:Bacillus thuringiensis / Q000235:genetics*; D001483:Base Sequence / Q000235:genetics; D015152:Blotting, Northern / Q000379:methods; D003001:Cloning, Molecular / Q000379:methods; D056931:Cryptochromes; D004269:DNA, Bacterial / Q000235:genetics; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000235:genetics*; D015870:Gene Expression / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization / Q000235:genetics; D017956:Photoreceptor Cells, Invertebrate; D011401:Promoter Regions, Genetic / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D043562:Receptors, G-Protein-Coupled; D015183:Restriction Mapping / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
D056931:Cryptochromes; D004269:DNA, Bacterial; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D012329:RNA, Bacterial; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila