Tzareva N V, Makhno V I, Boni I V
M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow.
FEBS Lett. 1994 Jan 10;337(2):189-94. doi: 10.1016/0014-5793(94)80271-8.
In an attempt to understand how Escherichia coli ribosomes recognize the initiator codon on mRNAs lacking the Shine-Dalgarno (SD) sequence, we have studied 30S initiation complex formation in extension inhibition (toeprinting) experiments using (-SD)mRNAs which are known to be reliably translated in E. coli: the plant viral messenger A1MV RNA 4 and two chimaeric mRNAs coding for beta-glucuronidase (GUS) and bearing the 5'-untranslated sequence of TMV RNA (omega) or the omega-derived sequence (CAA)n as 5'-leaders. Ribosomal protein S1 and IF3 have been found to be indispensable for translational initiation. Protein S1 appears to be a key recognition element. S1 binds to sequences within the leaders of (-SD)mRNAs thus providing their affinity to E. coli ribosomes.
为了了解大肠杆菌核糖体如何识别缺乏Shine-Dalgarno（SD）序列的mRNA上的起始密码子，我们在延伸抑制（足迹法）实验中研究了30S起始复合物的形成，该实验使用了已知在大肠杆菌中能可靠翻译的（-SD）mRNA：植物病毒信使A1MV RNA 4和两个编码β-葡萄糖醛酸酶（GUS）的嵌合mRNA，它们带有烟草花叶病毒RNA（ω）的5'-非翻译序列或ω衍生序列（CAA）n作为5'-前导序列。已发现核糖体蛋白S1和IF3对于翻译起始是必不可少的。蛋白S1似乎是关键的识别元件。S1与（-SD）mRNA前导序列内的序列结合，从而赋予它们对大肠杆菌核糖体的亲和力。
