Picken R N, Mazaitis A J, Maas W K, Rey M, Heyneker H
Infect Immun. 1983 Oct;42(1):269-75. doi: 10.1128/iai.42.1.269-275.1983.
Previously, the gene for heat-stable enterotoxin II (STII) has been mapped by transposon Tn5 insertion mutagenesis in the chimeric R-Ent plasmid pCG86 (Mazaitis, A. J., R. Maas, and W. K. Maas, J. Bacteriol. 145:97-105, 1981). DNA segments containing this gene were cloned from the wild-type and STII-insertion-mutant plasmid. The position of the Tn5 insertion was determined, and a 530-base-pair-long segment of the wild-type plasmid corresponding to the Tn5 insertion site was sequenced. An open reading frame for the STII gene was identified and is characterized by typical promoter and ribosome binding site sequences. The deduced STII structural gene codes for a protein 71 amino acids long, including a typical signal peptide of 23 amino acids and a mature protein of 48 amino acids. The size and overall structure of STII are similar to those of STI, but the amino acid compositions of the two heat-stable enterotoxins are completely different.
以前，热稳定肠毒素II（STII）基因已通过转座子Tn5插入诱变定位在嵌合R-Ent质粒pCG86中（马扎伊蒂斯，A. J.，R. 马斯，和W. K. 马斯，《细菌学杂志》145:97 - 105，1981年）。从野生型和STII插入突变体质粒中克隆了含有该基因的DNA片段。确定了Tn5插入的位置，并对野生型质粒中对应于Tn5插入位点的一段530个碱基对长的片段进行了测序。鉴定出了STII基因的一个开放阅读框，其特征为典型的启动子和核糖体结合位点序列。推导的STII结构基因编码一种71个氨基酸长的蛋白质，包括一个23个氨基酸的典型信号肽和一个48个氨基酸的成熟蛋白。STII的大小和整体结构与STI相似，但两种热稳定肠毒素的氨基酸组成完全不同。
