Edens L, Heslinga L, Klok R, Ledeboer A M, Maat J, Toonen M Y, Visser C, Verrips C T
Gene. 1982 Apr;18(1):1-12. doi: 10.1016/0378-1119(82)90050-6.
The structural gene of the sweet-tasting plant protein (prepro)thaumatin was cloned and expressed in Escherichia coli. Expression was effected under control of lac and trp promoter/operator systems and through the use of bacterial ribosome-binding sites. The naturally occurring thaumatin II represents a processed form. The primary translation product, preprothaumatin, of the cloned mRNA-derived cDNA contains extensions at both the amino terminus and the carboxy terminus. The amino terminal extension of 22 amino acids is hydrophobic and very much resembles an excretion-related signal sequence. The six amino acids-long carboxy terminal extension is very acidic in character, in contrast to the overall highly basic thaumatin molecule. The possible role of such an acidic tail with respect to compartmentalization is discussed.
甜味植物蛋白（前体）奇异果甜蛋白的结构基因被克隆并在大肠杆菌中表达。表达是在乳糖和色氨酸启动子/操纵子系统的控制下，并通过使用细菌核糖体结合位点来实现的。天然存在的奇异果甜蛋白II代表一种加工形式。克隆的源自mRNA的cDNA的初级翻译产物，即前体奇异果甜蛋白，在氨基末端和羧基末端都有延伸。22个氨基酸的氨基末端延伸是疏水的，非常类似于与排泄相关的信号序列。与整体高度碱性的奇异果甜蛋白分子相比，六个氨基酸长的羧基末端延伸在性质上是非常酸性的。讨论了这种酸性尾巴在区室化方面可能的作用。
