Department of Molecular, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309-0347, USA.
Proc Natl Acad Sci U S A. 2010 Mar 9;107(10):4585-9. doi: 10.1073/pnas.0912895107. Epub 2010 Feb 22.
An indispensable step in protein biosynthesis is the 2(')(3(')) aminoacylation of tRNA by aminoacyl-tRNA synthetases. Here we show that a similar activity exists in a tiny, 5-nt-long RNA enzyme with a 3-nt active center. The small ribozyme initially trans-phenylalanylates a partially complementary 4-nt RNA selectively at its terminal 2(')-ribose hydroxyl using PheAMP, the natural form for activated amino acid. The initial 2(') Phe-RNA product can be elaborated into multiple peptidyl-RNAs. Reactions do not require divalent cations, and have limited dependence on monovalent cations. Small size and minimal requirements for regiospecific translational activity strongly support the hypothesis that minuscule RNA enzymes participated in early forms of translation.
蛋白质生物合成过程中不可或缺的一步是氨酰-tRNA 合成酶对 tRNA 的 2'（3'）氨基酰化。在这里，我们展示了一种类似的活性存在于一个微小的、5 个核苷酸长的 RNA 酶中，其 3 个核苷酸的活性中心。这个小核酶最初使用苯丙氨酸 AMP（天然形式的活化氨基酸）选择性地在其末端 2' -核糖羟基上反式苯丙氨酰化部分互补的 4 个核苷酸 RNA。初始的 2' 苯丙氨酸-RNA 产物可以被进一步加工成多种肽-RNA。反应不需要二价阳离子，并且对单价阳离子的依赖性有限。小尺寸和对区域特异性翻译活性的最小要求强烈支持这样一种假说，即微小的 RNA 酶参与了早期形式的翻译。
