美国耶鲁大学医学院Joan A. Steitz研究组取得最新进展。他们揭示通过poly（A）尾部3′-末端结合袋和poly（A）-RNA相互作用的其他方式稳定RNA。相关论文于2021年1月7日发表于国际顶尖学术期刊《科学》。

水稻hAT转座子mRNA与poly（A）28复合的双ENE的2.89-Å分辨率晶体结构揭示了与poly（A）相互作用的多种模式，包括主要凹槽三重螺旋、扩展的微小凹槽与RNA 双螺旋的相互作用，一个基于五元组的基序，将poly（A）从次要凹槽关联转变为主要凹槽的三重螺旋，以及一个poly（A）3′-末端结合袋。他们的发现既扩展了与RNA长距离相互作用所涉及的基序，又提供了关于聚腺苷酸化如何保护RNA极端3′末端的见解。

据悉，Poly（A）尾部添加到各种RNA的3'末端是高度保守的修饰，在细胞RNA功能中起着核心作用。核表达元件（ENEs）是顺式作用的RNA元件，通过将多尾部隔离在RNA三链体结构中来稳定它们。

附：英文原文

Title: RNA stabilization by a poly(A) tail 3-end binding pocket and other modes of poly(A)-RNA interaction

Author: Seyed-Fakhreddin Torabi, Anand T. Vaidya, Kazimierz T. Tycowski, Suzanne J. DeGregorio, Jimin Wang, Mei-Di Shu, Thomas A. Steitz, Joan A. Steitz

Issue&Volume: 2021/01/07

Abstract: Poly(A) tail addition to the 3 end of a wide range of RNAs is a highly conserved modification that plays a central role in cellular RNA function. Elements for nuclear expression (ENEs) are cis-acting RNA elements that stabilize poly(A) tails by sequestering them in RNA triplex structures. A 2.89- resolution crystal structure of a double ENE from a rice hAT transposon mRNA complexed with poly(A)28 reveals multiple modes of interaction with poly(A), including major-groove triple helices, extended minor-groove interactions with RNA double helices, a quintuple-base motif that transitions poly(A) from minor-groove associations to major-groove triple helices, and a poly(A) 3-end binding pocket. Our findings both expand the repertoire of motifs involved in long-range RNA interactions and provide insights into how polyadenylation can protect an RNA’s extreme 3 end.

DOI: 10.1126/science.abe6523

Source: https://science.sciencemag.org/content/early/2021/01/07/science.abe6523