Sakamoto H, Bellalou J, Sebo P, Ladant D
Unité de Biochimie des Régulations Cellulaires, Institut Pasteur, Paris, France.
J Biol Chem. 1992 Jul 5;267(19):13598-602.
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.
百日咳博德特氏菌钙调蛋白依赖性腺苷酸环化酶（CyaA）是一种由1706个氨基酸残基组成的毒素，具有溶血活性。我们构建了产生缺乏腺苷酸环化酶活性的修饰CyaA的百日咳博德特氏菌突变株。我们的结果表明，这种修饰的CyaA表现出与野生型毒素相同的溶血活性，从而证明溶血活性与腺苷酸环化酶活性无关。此外，构建了产生缺乏催化结构域（第1 - 373位氨基酸残基）的CyaA的百日咳博德特氏菌和大肠杆菌菌株。截短的蛋白表现出与野生型毒素相当的溶血活性，从而确定仅羧基末端的1332个氨基酸残基具有溶血活性。这些发现共同表明，腺苷酸环化酶活性和溶血活性位于分子的两个不同区域（分别约为第1 - 400位氨基酸和第401 - 1706位氨基酸），并且CyaA的这两个区域在功能上是独立的。
