Li S J, Wu J J, Marshall A G
Biochemistry. 1987 Mar 24;26(6):1578-85. doi: 10.1021/bi00380a014.
A "common-arm" fragment from wheat germ (Triticum aestivum) 5S RNA has been produced by enzymatic cleavage with RNase T1 and sequenced via autoradiography of electrophoresis gels for the end-labeled fragments obtained by further RNase T1 partial digestion. The existence, base pair composition, and base pair sequence of the common arm are demonstrated for the first time by means of proton 500-MHz nuclear magnetic resonance. From Mg2+ titration, temperature variation, ring current calculations, sequence comparisons, and proton homonuclear Overhauser enhancement experiments, additional base pairs in the common arm of the eukaryotic 5S RNA secondary structure are detected. Two base pairs, G41 X C34 and A42 X U33 in the hairpin loop, could account for the lack of binding between the conserved GAAC segment of 5S RNA and the conserved Watson-Crick-complementary GT psi C segment of tRNAs.
从小麦胚芽（普通小麦）5S RNA中通过核糖核酸酶T1酶切产生了一个“共有臂”片段，并通过对经进一步核糖核酸酶T1部分消化获得的末端标记片段进行电泳凝胶放射自显影测序。首次借助500兆赫质子核磁共振证实了共有臂的存在、碱基对组成和碱基对序列。通过镁离子滴定、温度变化、环流计算、序列比较和质子同核Overhauser增强实验，在真核生物5S RNA二级结构的共有臂中检测到了额外的碱基对。发夹环中的两个碱基对G41×C34和A42×U33，可能解释了5S RNA保守的GAAC区段与tRNA保守的沃森-克里克互补GTψC区段之间缺乏结合的原因。
