Cloning and characterization of a mosquito larvicidal toxin produced during vegetative stage of Bacillus sphaericus 2297.
The mosquitocidal toxin 1 (mtx1) gene from genomic DNA of B. sphaericus strain 2297 was cloned and expressed in E. coli. DNA sequencing analysis of the cloned gene revealed a single open reading frame encoding an 870-amino acid polypeptide. Expression level of the full-length gene in E. coli was very low even though strong promoter was used or the gene was expressed as a fusion protein. Expression level was highly improved after the putative leader sequence was deleted, and the truncated gene was expressed as a fusion protein with glutathione S-transferase (GST-tMtx1). E. coli cells expressing GST-tMtx1 was highly toxic to Culex quinquefasciatus larvae and showed lower toxicity against Anopheles dirus and Aedes aegypti larvae. Enterobacter amnigenus An11, a mosquito larval gut colonizable bacteria, transformed with the cloned gene exhibited mosquito larvicidal activity. Result suggested that there is a potential to develop this protein to be used as an alternative mosquito control agent.
Promdonkoy
Boonhiang
B
National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand. boonhiang@biotec.or.th
Promdonkoy
Patcharee
P
Tanapongpipat
Sutipa
S
Luxananil
Plearnpis
P
Chewawiwat
Namchai
N
Audtho
Mongkon
M
Panyim
Sakol
S
D000818:Animals; D001407:Bacillus / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000235:genetics* / Q000494:pharmacology*; D003001:Cloning, Molecular; D009033:Culicidae / Q000187:drug effects*; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004754:Enterobacter / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D007306:Insecticides / Q000494:pharmacology; D007814:Larva / Q000187:drug effects; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D007306:Insecticides; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C046134:binB protein, Bacillus sphaericus; D005982:Glutathione Transferase