[A new model of translational control of gene expression in polycistron++ of AB5 entrerotoxin].
The expression level of the B subunit gene of cholera toxin (ctx) and E. coli heat labile toxin (ltx) is five to seven times more than that of A subunit gene. In these studies, a 80 basepair translation regulation element was found located in the structure gene of A gene of both toxin operon which consists of three translation initiation region. Site-directed mutation of the initiation codon of TIR3 resulted in the 9 time decrease of the expression of the downstream cistron which was translational coupled with A gene. The results indicated that translation from the internal of A gene and translation coupling are responsible for the differential expression level of the A and B gene of AB5 enterotoxin.
Cao
C
C
Institute of Biotechnology, Academy of Military Medical Sciences, Beijing, China.
Li
P
P
Wang
P
P
Li
J Z
JZ
Shi
C H
CH
Ma
Q J
QJ
D001427:Bacterial Toxins / Q000235:genetics*; D001483:Base Sequence; D002772:Cholera Toxin / Q000235:genetics*; D004768:Enterotoxins / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009876:Operon; D014176:Protein Biosynthesis
D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D002772:Cholera Toxin; C027538:heat-labile enterotoxin, E coli