兔肝细胞质起始转运核糖核酸中G-T-φ-C-G(A)序列被G-A-U-C-G-取代。

Simsek M, Petrissant G, Rajbhandary U L

Proc Natl Acad Sci U S A. 1973 Sep;70(9):2600-4. doi: 10.1073/pnas.70.9.2600.

Eukaryotic cytoplasmic initiator tRNAs lack the sequence G-T-Psi-C-G(A)-, which is in every tRNA of known sequence that is active in protein biosynthesis. In initiator tRNA of yeast cytoplasm, which is the only eukaryotic initiator tRNA of known sequence, this sequence is replaced by G-A-U-C-G-. We now report the sequence of a 30-nucleotide-long, 3'-terminal fragment of cytoplasmic initiator tRNA of rabbit liver obtained by specific cleavage of the tRNA at the site occupied by the modified nucleoside, 7-methyl guanosine. We show (i) that in rabbit-liver initiator tRNA also, the sequence G-T-Psi-C-G(A)- is replaced by G-A-U-C-G- and (ii) that the sequences of loop IV of both the yeast and rabbit-liver cytoplasmic initiator tRNAs are identical, A-U-C-G-m(1)-A-A-A-.

真核细胞质起始tRNA缺乏序列G-T-ψ-C-G(A)-，而在已知序列的、在蛋白质生物合成中具有活性的每一种tRNA中都存在该序列。在酵母细胞质起始tRNA（这是已知序列的唯一真核起始tRNA）中，该序列被G-A-U-C-G-所取代。我们现在报道了通过在修饰核苷7-甲基鸟苷占据的位点对兔肝细胞质起始tRNA进行特异性切割而获得的一个30个核苷酸长的3'-末端片段的序列。我们发现：（i）在兔肝起始tRNA中，序列G-T-ψ-C-G(A)-同样被G-A-U-C-G-所取代；（ii）酵母和兔肝细胞质起始tRNA的环IV序列相同，即A-U-C-G-m(1)-A-A-A-。