Glaser P, Danchin A, Ladant D, Barzu O, Ullmann A
Départment de Biochimie et Génétique Moléculaire, Institut Pasteur, Paris, France.
Tokai J Exp Clin Med. 1988;13 Suppl:239-52.
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.
利用腺苷酸环化酶 - 钙调蛋白相互作用作为工具，将百日咳博德特氏菌的cya基因克隆到一个携带高表达钙调蛋白质粒的cya缺陷型大肠杆菌菌株中。该基因核苷酸序列的测定表明，腺苷酸环化酶作为一个由1706个氨基酸组成的大前体被合成。钙调蛋白刺激的催化活性存在于氨基末端的400个氨基酸中，而前体的1300个氨基酸羧基末端部分具有溶血活性。具有催化活性的43 kDa形式的腺苷酸环化酶由两个结构域组成：25 kDa的N末端结构域包含催化位点，18 kDa的C末端结构域携带主要的钙调蛋白结合位点。在百日咳博德特氏菌、炭疽芽孢杆菌和大鼠脑腺苷酸环化酶之间建立的免疫相关性表明，这些钙调蛋白刺激酶的中央结构域有共同的进化起源。腺苷酸环化酶 - 溶血素双功能蛋白（环溶血素）的分泌需要另外三个与cya基因相邻的基因表达。这四个基因似乎形成一个单一的操纵子。双功能蛋白的分泌机制应与大肠杆菌α - 溶血素所描述的机制相似。
