Developmental Biology Program, The Ohio State University, Columbus, Ohio 43210.
Plant Physiol. 1978 Nov;62(5):838-40. doi: 10.1104/pp.62.5.838.
Evidence is presented for the occurrence of 5'-terminal capping structures in the polyadenylated RNA of oat (Avena sativa) coleoptiles. These structures are composed of an inverted terminal nucleoside containing the modified base 7-methylguanine which is joined 5' to 5' with a second (penultimate) nucleoside by means of three phosphate groups in two pyrophosphate linkages. The penultimate nucleoside is joined to the remainder of the RNA molecule by a conventional 3',5' phosphodiester bond. A significant difference between the cap structures of oat coleoptile RNA and those of previously described higher eucaryotic cellular mRNAs is the lack of ribose methylations in the penultimate nucleosides of the plant RNA.
本文提出了燕麦（Avena sativa）幼茎多聚腺苷酸 RNA 中存在 5′-端加帽结构的证据。这些结构由含有修饰碱基 7-甲基鸟嘌呤的反式末端核苷酸组成，通过两个焦磷酸键中的三个磷酸基团 5' 到 5' 与第二个（倒数第二个）核苷酸连接。倒数第二个核苷酸通过常规的 3'，5' 磷酸二酯键与 RNA 分子的其余部分连接。燕麦幼茎 RNA 加帽结构与先前描述的高等真核细胞 mRNA 加帽结构的一个显著区别是植物 RNA 中倒数第二个核苷酸缺乏核糖甲基化。
