Inactivation of the Escherichia coli heat-labile enterotoxin by in vitro mutagenesis of the A-subunit gene.
In vitro mutagenesis of the LTA gene, encoding the A subunit of the Escherichia coli heat-labile enterotoxin, has been used to obtain A subunits deficient in enzymic activity. One inactive A-subunit mutant which contained two amino acid substitutions, was shown to associate with native B subunits to form a holotoxoid lacking toxin activity. A serine to phenylalanine mutation appears to be responsible for the loss of toxicity.
Harford
S
S
Fermentation Development Department, Glaxochem, Ulverston.
Dykes
C W
CW
Hobden
A N
AN
Read
M J
MJ
Halliday
I J
IJ
D000595:Amino Acid Sequence; D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D001483:Base Sequence; D001681:Biological Assay; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D015246:Deoxyribonuclease EcoRI; D015252:Deoxyribonucleases, Type II Site-Specific; D004768:Enterotoxins / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D007082:Ileum / Q000378:metabolism; D007163:Immunosorbent Techniques; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D011817:Rabbits
D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C027538:heat-labile enterotoxin, E coli; D015246:Deoxyribonuclease EcoRI; C025580:endodeoxyribonuclease XBAI; D015252:Deoxyribonucleases, Type II Site-Specific