Haugland R A, Cline M G
Eur J Biochem. 1980 Feb;104(1):271-7. doi: 10.1111/j.1432-1033.1980.tb04425.x.
Evidence is presented for the occurrence of 5'-terminal capping structures in poly(A)-rich RNAs from oat coleoptile tissue. Similar to the cap structures in mRNA from other eukaryotic organisms, the 5' terminus of these oat coleoptile RNA molecules consists of 7-methylguanosine joined 5' to 5' with the adjacent (penultimate) nucleoside by means of three phosphate groups in two pyrophosphate linkages. The penultimate nucleoside contains primarily purine bases, but small amounts of pyrimidines (cytidine) are also detectable. Some monophosphorylated 5'-termini were also detected, however, they appear to occur as a result of RNA degradation. In addition to the 5 cap, oat RNA molecules are also post-transcriptionally modified with a low frequency of N6-methylations of internal adenosines.
有证据表明燕麦胚芽鞘组织富含多聚腺苷酸的RNA中存在5'-末端帽状结构。与其他真核生物mRNA中的帽状结构相似，这些燕麦胚芽鞘RNA分子的5'末端由7-甲基鸟苷通过两个焦磷酸键中的三个磷酸基团与相邻（倒数第二个）核苷以5'至5'相连。倒数第二个核苷主要含有嘌呤碱基，但也可检测到少量嘧啶（胞苷）。还检测到了一些单磷酸化的5'-末端，然而，它们似乎是RNA降解的结果。除了5'帽，燕麦RNA分子在转录后还会进行内部腺苷N6-甲基化修饰，但其频率较低。
