Huang Lin, Lilley David M J
Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom.
Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom.
J Mol Biol. 2016 Feb 27;428(5 Pt A):790-801. doi: 10.1016/j.jmb.2015.09.026. Epub 2015 Oct 29.
Kink turns (k-turns) are widespread structural elements that introduce an axial bend into duplex RNA with an included angle of 50°. These mediate key tertiary interactions and bind specific proteins including members of the L7Ae family. The standard k-turn comprises a three-nucleotide bulge followed by G·A and A·G pairs. The RNA kinks by an association of the two minor grooves, stabilized by the formation of a number of key cross-strand hydrogen bonds mostly involving the adenine bases of the G·A and A·G pairs. The k-turns may be divided into two conformational classes, depending on the receptor for one of these hydrogen bonds. k-turns become folded by one of three different processes. Some, but not all, k-turns become folded in the presence of metal ions. Whether or not a given k-turn is folded under these conditions is determined by its sequence. We present a set of rules for the prediction of folding properties and the structure adopted on local sequence.
扭结转角（k-turns）是广泛存在的结构元件，可在双链RNA中引入50°夹角的轴向弯曲。它们介导关键的三级相互作用，并结合包括L7Ae家族成员在内的特定蛋白质。标准的扭结转角由一个三核苷酸凸起，其后跟着G·A和A·G碱基对组成。RNA通过两个小沟的结合而发生扭结，这通过形成一些主要涉及G·A和A·G碱基对中腺嘌呤碱基的关键跨链氢键得以稳定。根据这些氢键之一的受体，扭结转角可分为两种构象类型。扭结转角通过三种不同过程之一进行折叠。一些（但不是全部）扭结转角在金属离子存在下会发生折叠。在这些条件下给定的扭结转角是否折叠取决于其序列。我们提出了一套用于预测折叠特性以及局部序列所采用结构的规则。
