title: Bordetella pertussis adenylate cyclase toxin. Structural and functional independence of the catalytic and hemolytic activities.
abstract: The Bordetella pertussis calmodulin-dependent adenylate cyclase (CyaA) is a 1706-residue-long toxin, endowed with hemolytic activity. We have constructed B. pertussis mutant strains producing modified CyaAs devoid of adenylate cyclase activity. Our results show that such modified CyaAs display hemolytic activity identical to the wild-type toxin, thus demonstrating that the hemolytic activity is independent of the adenylate cyclase activity. Furthermore, B. pertussis and Escherichia coli strains producing CyaA lacking the catalytic domain (residues 1-373) were constructed. The truncated protein exhibits hemolytic activity comparable to the wild-type toxin, thus establishing that the carboxyl-terminal 1332 residues alone are endowed with hemolytic activity. Together, these findings show that adenylate cyclase and hemolytic activities are located in two distinct regions of the molecule (respectively, approximately amino acids 1-400 and 401-1706) and that the two regions of CyaA are functionally independent.
authors.affiliation: Unité de Biochimie des Régulations Cellulaires, Institut Pasteur, Paris, France.
authors.forename: H
authors.initials: H
authors.lastname: Sakamoto
authors.forename: J
authors.initials: J
authors.lastname: Bellalou
authors.forename: P
authors.initials: P
authors.lastname: Sebo
authors.forename: D
authors.initials: D
authors.lastname: Ladant
mesh_terms: D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001886:Bordetella pertussis / Q000201:enzymology* / Q000235:genetics; D002384:Catalysis; D002470:Cell Survival / Q000187:drug effects; D002876:Chromosomes, Bacterial; D004269:DNA, Bacterial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006461:Hemolysis; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D010957:Plasmids; D012756:Sheep; D010566:Virulence Factors, Bordetella / Q000235:genetics* / Q000633:toxicity
chemical_list: D037361:Adenylate Cyclase Toxin; D004269:DNA, Bacterial; D010566:Virulence Factors, Bordetella; D000262:Adenylyl Cyclases