TY - JOUR
T1 - Design and construction of a synthetic Bacillus thuringiensis Cry4Aa gene
T2 - Hyperexpression in Escherichia coli
AU - Hayakawa, Tohru
AU - Howlader, Mohammad Tofazzal Hossain
AU - Yamagiwa, Masashi
AU - Sakai, Hiroshi
N1 - Funding Information:
Acknowledgement We are grateful to the Dainihon Jochugiku Co., Ltd. for providing us with eggs of C. pipiens. This work was supported by a grant from the Program for Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN), Japan and by research grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
PY - 2008/10
Y1 - 2008/10
N2 - Cry4Aa produced by Bacillus thuringiensis is a dipteran-specific toxin and is, therefore, of great interest for developing a bioinsecticide to control mosquitoes. However, the expression of Cry4Aa in Escherichia coli is relatively low, which is a major disadvantage in its development as a bioinsecticide. In this study, to establish an effective production system, a 1,914-bp modified gene (cry4Aa-S1) encoding Cry4Aa was designed and synthesized in accordance with the G+C content and codon preference of E. coli genes without altering the encoded amino acid sequence. The cry4Aa-S1 gene allowed a significant improvement in expression level, over five-fold, compared to that of the original cry4Aa gene. The product of the cry4Aa-S1 gene showed the same level of insecticidal activity against Culex pipiens larvae as that from cry4Aa. This suggested that unfavorable codon usage was one of the reasons for poor expression of cry4Aa in E. coli, and, therefore, changing the cry4Aa codons to accord with the codon usage in E. coli led to efficient production of Cry4Aa. Efficient production of Cry4Aa in E. coli can be a powerful measure to prepare a sufficient amount of Cry4Aa protein for both basic analytical and applied researches.
AB - Cry4Aa produced by Bacillus thuringiensis is a dipteran-specific toxin and is, therefore, of great interest for developing a bioinsecticide to control mosquitoes. However, the expression of Cry4Aa in Escherichia coli is relatively low, which is a major disadvantage in its development as a bioinsecticide. In this study, to establish an effective production system, a 1,914-bp modified gene (cry4Aa-S1) encoding Cry4Aa was designed and synthesized in accordance with the G+C content and codon preference of E. coli genes without altering the encoded amino acid sequence. The cry4Aa-S1 gene allowed a significant improvement in expression level, over five-fold, compared to that of the original cry4Aa gene. The product of the cry4Aa-S1 gene showed the same level of insecticidal activity against Culex pipiens larvae as that from cry4Aa. This suggested that unfavorable codon usage was one of the reasons for poor expression of cry4Aa in E. coli, and, therefore, changing the cry4Aa codons to accord with the codon usage in E. coli led to efficient production of Cry4Aa. Efficient production of Cry4Aa in E. coli can be a powerful measure to prepare a sufficient amount of Cry4Aa protein for both basic analytical and applied researches.
KW - Bacillus thuringiensis
KW - Bioinsecticide
KW - Cry4Aa
KW - Escherichia coli
KW - Hyperexpression
KW - Synthetic gene
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U2 - 10.1007/s00253-008-1560-9
DO - 10.1007/s00253-008-1560-9
M3 - Article
C2 - 18751699
AN - SCOPUS:53249124647
VL - 80
SP - 1033
EP - 1037
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
SN - 0175-7598
IS - 6
ER -