title: Catabolite repression of Escherichia coli heat-stable enterotoxin activity.
abstract: The Escherichia coli heat-stable enterotoxin (ST) coded for by plasmid pYK007 (Apr ST+) showed a dependence for cyclic adenosine 3',5'-monophosphate (cAMP) to express ST activity in an adenyl cyclase (cya) deletion mutant; no ST activity was detected in the presence of cAMP in a cAMP receptor protein (crp) deletion mutant or in a double deletion mutant (delta cya delta crp). The cya-crp effect on ST activity could not be accounted for by a modification of the copy number of plasmid deoxyribonucleic acid per chromosome equivalent or by an alteration in the secretion of an active intracellular enterotoxin.
mesh_terms: D001427:Bacterial Toxins / Q000235:genetics*; D002872:Chromosome Deletion; D004768:Enterotoxins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005786:Gene Expression Regulation; D005796:Genes; D009154:Mutation; D010957:Plasmids; D011953:Receptors, Cyclic AMP / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D011953:Receptors, Cyclic AMP