在大肠杆菌中，多胺对mRNA翻译的影响程度决定于Shine-Dalgarno (SD)序列局部结构。与信使RNA其它区域松散配对的SD序列的局部结构受多胺的扰动较大，其局部解链的概率也较大，因而SD序列结合到核糖体RNA上并启动蛋白质翻译的概率也较大，相反，则启动mRNA翻译的概率就会较小。基于此，建立一个简单数学模型来描述这一现象，即蛋白质的表达水平是与由多胺刺激而引起mRNA的SD序列局部暴露的概率相关的。结果显示，模型与实验结果相符的很好。

We established a simple mathematical model that the degree of polyamine stimulation of mRNA translation was dependent on the structure of the Shine-Dalgarno (SD) sequence in Escherichia coli. Loose base pairing of the SD sequence with other regions of mRNA caused strong polyamine stimulation, while intense base pairing of the SD sequence with other regions of the mRNA resulted in insignificant weak polyamine stimulation. The result suggested that the protein expression level was relative to the exposure probability of the SD sequence from its base paired state by the polyamine stimulation. The model agreed well with the experimental analysis.