Identification of a common domain in calmodulin-activated eukaryotic and bacterial adenylate cyclases.
Bordetella pertussis and Bacillus anthracis, two taxonomically distinct bacteria, secrete adenylate cyclase toxins that are activated by the eukaryotic protein calmodulin. The two enzymes contain a well-conserved stretch of 24 amino acid residues [Escuyer et al. (1988) Gene 71, 293-298]. Antibodies have been obtained against two synthetic heptadecapeptides, covering part of the conserved sequences. The anti-peptide antibodies specifically reacted in Western blots with the rat brain adenylate cyclase as well as with the two bacterial enzymes. Anti-rat brain adenylate cyclase serum contained antibodies that were retained by the immobilized peptides, and the affinity-purified antibodies yielded the same recognition pattern of the eukaryotic enzyme as did the unfractionated serum. These results indicate that the eukaryotic adenylate cyclase contains an epitope closely related to that specified by the conserved bacterial sequence. The synthetic peptides and the bacterial adenylate cyclases appeared to compete for ATP (KD of the ATP-peptide complex ca. 0.2 mM), suggesting that the conserved sequence may be part of the substrate binding site in these two enzymes.
Goyard
S
S
Département de Biochimie et Génétique Moléculaire, Institut Pasteur, Paris, France.
Orlando
C
C
Sabatier
J M
JM
Labruyere
E
E
d'Alayer
J
J
Fontan
G
G
van Rietschoten
J
J
Mock
M
M
Danchin
A
A
Ullmann
A
A
D000262:Adenylyl Cyclases / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D001408:Bacillus anthracis / Q000201:enzymology*; D001665:Binding Sites; D015153:Blotting, Western; D001886:Bordetella pertussis / Q000201:enzymology*; D001921:Brain / Q000201:enzymology*; D002147:Calmodulin / Q000502:physiology; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D051381:Rats; D013045:Species Specificity
D002147:Calmodulin; D000939:Epitopes; D010446:Peptide Fragments; D000262:Adenylyl Cyclases