Jucker F M, Pardi A
Department of Chemistry and Biochemistry, University of Colorado at Boulder 80309-0215, USA.
RNA. 1995 Apr;1(2):219-22.
The U-turn (uridine turn) is an RNA structural motif that contains a change in backbone direction stabilized by specific interactions across the bend. It was first identified in the anticodon loop and the T-loop of yeast tRNA(Phe) (Quigley & Rich, 1976, Science 194:796-806) and has recently also been found in the crystal structure of the hammerhead ribozyme (Pley HW, Flaherty KM, McKay DB, 1994a, Nature 372:68-74). These U-turn motifs follow a UNR consensus sequence (where N is any nucleotide and R is G or A). Here we report that the frequently occurring GNRA tetraloops also contain a U-turn motif, and we discuss the role of U-turns as abundant tertiary structural motifs in RNA.
U型转弯（尿苷转弯）是一种RNA结构基序，其包含由跨越弯曲处的特定相互作用稳定的主链方向变化。它最初在酵母tRNA（苯丙氨酸）的反密码子环和T环中被鉴定出来（奎格利和里奇，1976年，《科学》194:796 - 806），最近在锤头状核酶的晶体结构中也被发现（普利HW、弗莱厄蒂KM、麦凯DB，1994a，《自然》372:68 - 74）。这些U型转弯基序遵循UNR共有序列（其中N是任何核苷酸，R是G或A）。在此我们报告，频繁出现的GNRA四环也包含一个U型转弯基序，并且我们讨论了U型转弯作为RNA中丰富的三级结构基序的作用。
