Nicosia A, Perugini M, Franzini C, Casagli M C, Borri M G, Antoni G, Almoni M, Neri P, Ratti G, Rappuoli R
Proc Natl Acad Sci U S A. 1986 Jul;83(13):4631-5. doi: 10.1073/pnas.83.13.4631.
Pertussis toxin, a protein composed of five different subunits (S1, S2, S3, S4, and S5), is the major virulence factor of Bordetella pertussis. We have cloned and sequenced a DNA fragment of 4.7 kilobases that contains the genes coding for the five subunits. The genes are clustered within 3.2 kilobases in the following order: S1, S2, S4, S5, and S3. A sequence closely resembling Escherichia coli promoters is found only before the S1 gene, and a possible termination signal is present at the end of the S3 gene, which suggests that the pertussis toxin genes are organized in a single operon. A possible Shine-Dalgarno sequence is present before the S1 gene but not before the other four genes that 8-12 nucleotides upstream from the ATG codon show a new consensus sequence, 5'TCC(T)GG3', possibly involved in the regulation of translation. We have also found sequence homology between the S2 and S3 genes and their protein products indicating that gene duplication played a major role in the evolution of pertussis toxin.
百日咳毒素是一种由五个不同亚基（S1、S2、S3、S4和S5）组成的蛋白质，是百日咳博德特氏菌的主要毒力因子。我们克隆并测序了一个4.7千碱基的DNA片段，该片段包含编码这五个亚基的基因。这些基因按以下顺序聚集在3.2千碱基范围内：S1、S2、S4、S5和S3。仅在S1基因之前发现了一个与大肠杆菌启动子非常相似的序列，并且在S3基因末端存在一个可能的终止信号，这表明百日咳毒素基因是在一个单一操纵子中组织的。在S1基因之前存在一个可能的SD序列，但在其他四个基因之前不存在，ATG密码子上游8 - 12个核苷酸显示出一个新的共有序列5'TCC(T)GG3'，可能参与翻译调控。我们还发现S2和S3基因及其蛋白质产物之间存在序列同源性，这表明基因复制在百日咳毒素的进化中起了主要作用。
