[A promoter responsible for over-expression of cholera toxin B subunit in cholera toxin A subunit structure gene].
A promoter sequence, which promotes the transcription of cholera toxin B subunit gene, was found in cholera toxin A subunit structure gene. The transcription starts at the adenine Located at +833, that is 456bp upstream to the A of the initiation codon ATG of cholera toxin B gene. Under the control of the promoter, cholera toxin B subunit was over-expressed as high as 200 mg/L at an optimized culture condition. The chloramphenicol acetyl transferase gene and beta-galactosidase could also be efficiently expressed under the direction of the promoter. This promoter may be responsible for the 6 fold and 7 fold higher expression level of cholera toxin B subunit than cholera toxin A subunit in V. cholerae and Escheria coli respectively. The over-expression of CTB may be useful in preparing vaccine against cholera and facilitating the construction of peptide-bearing immunogenic hybrid proteins.
Cao
C
C
Institute of Biotechnology, Academy of Military Medical Sciences, Beijing.
Shi
C
C
Li
P
P
Ma
Q
Q
D001483:Base Sequence; D002772:Cholera Toxin / Q000235:genetics*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic
D002772:Cholera Toxin