Exotoxin A of Pseudomonas aeruginosa: evidence that domain I functions in receptor binding.
We have constructed defined deletions in the structural gene of Pseudomonas aeruginosa exotoxin A (ETA) in order to probe the function of Domain I of this protein. Three forms of the gene containing specific deletions were expressed in a strain of Escherichia coli K12 with lesions in the htpR and Ion genes; extracts containing the gene products were tested for ADP-ribosylation activity, cytotoxicity, and ability to protect sensitive cells from the cytotoxic action of authentic ETA. Two of the mutant ETAs gave concentration-dependent protection against authentic ETA, and protection correlated with the presence of the bulk of Domain I. The results support the notion that Domain I functions in binding the toxin to specific cell-surface receptors.
Guidi-Rontani
C
C
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115.
Collier
R J
RJ
D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D002352:Carrier Proteins; D002872:Chromosome Deletion; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics; D005098:Exotoxins / Q000235:genetics* / Q000378:metabolism; D005796:Genes; D005798:Genes, Bacterial; D007700:Kinetics; D009154:Mutation; D010957:Plasmids; D011485:Protein Binding; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D011956:Receptors, Cell Surface; D011950:Receptors, Cholinergic / Q000378:metabolism*; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D002352:Carrier Proteins; D004262:DNA Restriction Enzymes; D005098:Exotoxins; D011956:Receptors, Cell Surface; D011950:Receptors, Cholinergic; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C027553:Pseudomonas exotoxin binding protein, mouse