Watanabe K, Asai K, Oshima T, Kuchino Y
J Biochem. 1981 Nov;90(5):1259-66. doi: 10.1093/oxfordjournals.jbchem.a133590.
The nucleotide sequence of initiator tRNA (tRNAiMet) from Euphausia sperba, which was harvested in the Antarctic Sea, was determined to be pA-G-C-A-G-A-G-U-m1G-m2G-C-G-C-A-G-U-G-G-A-A-G-C-G-U-m2G-C-U-G-G-G-C-C-C-A-U-t6 A-A-C-C-C-A-G-A-G-m7G-U-C-G-G-U-A-G-A-psi-C-G-m1A-A-A-C-U-A-C-U-C-U-C-U-G-C-U-A -C-C-AOH by using post-labeling methods recently developed. The nucleotide sequence was very similar to that of mammalian tRNAiMet except for changes in six bases and three modifications: C16, U55, D47 and m5C48 are replaced by U16, psi 55 and unmodified U47 and C48, respectively. A50-U64 and G52-C62 base pairs of mammalian tRNAiMet are reversed in Euphausia tRNAiMet. In addition, the G49-C65 pair of the former is replaced by a less stable G49-U65 pair in Euphausia tRNAiMet. The sequence homology was compared between Euphausia tRNAiMet and over ten different species of eucaryotic tRNAiMet so far sequenced. The melting temperature of Euphausia tRNAiMet was 72.5 degrees C, which is 4.2 degrees C and 8.3 degrees C lower than those of rat liver and yeast tRNAiMet's, respectively. The origin of the thermal instability of Euphausia tRNAiMet is discussed in comparison of its secondary structure compared with those of other eucaryotic tRNAiMet's.
利用最近开发的后标记法，测定了在南极海域捕获的晶磷虾起始tRNA（tRNAiMet）的核苷酸序列为pA-G-C-A-G-A-G-U-m1G-m2G-C-G-C-A-G-U-G-G-A-A-G-C-G-U-m2G-C-U-G-G-G-C-C-C-A-U-t6A-A-C-C-C-A-G-A-G-m7G-U-C-G-G-U-A-G-A-psi-C-G-m1A-A-A-C-U-A-C-U-C-U-C-U-G-C-U-A-C-C-AOH。该核苷酸序列与哺乳动物的tRNAiMet非常相似，只是有六个碱基发生了变化以及三个修饰有所不同：C16、U55、D47和m5C48分别被U16、psi 55、未修饰的U47和C48取代。哺乳动物tRNAiMet的A50-U64和G52-C62碱基对在晶磷虾tRNAiMet中发生了颠倒。此外，前者的G49-C65碱基对在晶磷虾tRNAiMet中被稳定性较低的G49-U65碱基对所取代。将晶磷虾tRNAiMet与目前已测序的十多种不同真核生物tRNAiMet的序列同源性进行了比较。晶磷虾tRNAiMet的解链温度为72.5℃，分别比大鼠肝脏和酵母tRNAiMet的解链温度低4.2℃和8.3℃。通过将晶磷虾tRNAiMet的二级结构与其他真核生物tRNAiMet的二级结构进行比较，探讨了晶磷虾tRNAiMet热不稳定性的起源。
