Bruce A G, Atkins J F, Gesteland R F
Proc Natl Acad Sci U S A. 1986 Jul;83(14):5062-6. doi: 10.1073/pnas.83.14.5062.
The expression of certain normal genes requires a specific ribosomal frameshift event because the mRNA has the coding information for one protein in two different reading frames. One of several possible mechanisms for this involves recognition of a nontriplet codon by a noncognate tRNA. The AGUC-decoding Escherichia coli tRNASer3 reads a GCA alanine codon to cause a -1 frameshift. Replacement of the anticodon of tRNAPhe with the anticodon of tRNASer3 allows the constructed tRNA to cause this frameshifting. By altering the anticodon loop nucleotides at positions 33-36 in the constructed tRNAPhe molecules, the tRNA was found to recognize a 2-base codon. Instead of the usual anticodon, positions 34-36, the nucleotides in positions 34 and 35 form essential base pairs with the first two positions of the alanine codon. The uridine in position 36 is also required but not for base pairing.
某些正常基因的表达需要特定的核糖体移码事件，因为信使核糖核酸（mRNA）在两种不同的阅读框中具有一种蛋白质的编码信息。实现这一过程的几种可能机制之一涉及非同源转运核糖核酸（tRNA）对非三联体密码子的识别。解码AGUC的大肠杆菌tRNASer3读取丙氨酸密码子GCA从而导致-1移码。用tRNASer3的反密码子替换tRNAPhe的反密码子，使得构建的tRNA能够引发这种移码。通过改变构建的tRNAPhe分子中第33 - 36位的反密码子环核苷酸，发现该tRNA能够识别二碱基密码子。在位置34 - 36处，并非通常的反密码子，而是位置34和35处的核苷酸与丙氨酸密码子的前两个位置形成必需的碱基对。位置36处的尿苷也是必需的，但并非用于碱基配对。
