Bordetella pertussis adenylate cyclase: the gene and the protein.
Using the adenylate cyclase-calmodulin interaction as a tool, the B. pertussis cya gene was cloned in a cya defective E. coli strain harbouring a plasmid which expressed high levels of calmodulin. The determination of the nucleotide sequence of the gene showed that adenylate cyclase is synthesized as a large precursor of 1706 amino acids. The calmodulin-stimulated catalytic activity resides in the amino-terminal 400 amino acids whereas the 1300 amino acid carboxy-terminal part of the precursor is endowed with haemolytic activity. The catalytically active 43 kDa form of adenylate cyclase is organized in two domains: the N-terminal domain of 25 kDa harbors the catalytic site, and the 18 kDa C-terminal domain carries the main calmodulin-binding site. Immunological relatedness established between B. pertussis, B. anthracis and rat brain adenylate cyclases suggests a common evolutionary origin of a central domain of these calmodulin-stimulated enzymes. The secretion of the adenylate cyclase-haemolysin bifunctional protein (cyclolysin) requires the expression of three additional genes, contiguous to the cya gene. These four genes appear to form a single operon. The mechanism of secretion of the bifunctional protein should be similar to that described for E. coli alpha-haemolysin.
Glaser
P
P
Départment de Biochimie et Génétique Moléculaire, Institut Pasteur, Paris, France.
Danchin
A
A
Ladant
D
D
Barzu
O
O
Ullmann
A
A
D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001886:Bordetella pertussis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D002147:Calmodulin / Q000494:pharmacology; D005798:Genes, Bacterial; D007120:Immunochemistry; D008969:Molecular Sequence Data; D009876:Operon; D011498:Protein Precursors / Q000235:genetics; D013329:Structure-Activity Relationship
D037361:Adenylate Cyclase Toxin; D001426:Bacterial Proteins; D002147:Calmodulin; D011498:Protein Precursors; D000262:Adenylyl Cyclases