大肠杆菌4.5S RNA保守结构域IV的结晶及初步X射线分析

Crystallization and preliminary X-ray analysis of the conserved domain IV of Escherichia coli 4.5S RNA.

作者信息

Jovine L, Hainz T, Oubridge C, Nagai K

机构信息

MRC Laboratory of Molecular Biology, Cambridge CB2 2QH, England.

出版信息

Acta Crystallogr D Biol Crystallogr. 2000 Aug;56(Pt 8):1033-7. doi: 10.1107/s0907444900006910.

DOI:10.1107/s0907444900006910

PMID:10944346

Abstract

4.5S RNA forms with Ffh protein the prokaryotic signal recognition particle (SRP), a highly conserved ribonucleoprotein complex essential for protein secretion. It also independently binds to elongation factor G (EF-G) in the ribosome and has a function in a subset of translocation events that is transient but required for viability. Crystals of three different constructs encompassing the conserved domain IV of 4.5S RNA, containing the recognition elements for both Ffh and EF-G, were obtained. Native X-ray diffraction data were collected for two crystal forms under cryogenic cooling conditions. The best crystals are of a 45 nt construct, diffract anisotropically to 2.6 A resolution using synchrotron radiation and belong to space group P3(2)21, with unit-cell parameters a = b = 69.1, c = 84.6 A and a single RNA molecule per asymmetric unit.

摘要

4.5S RNA与Ffh蛋白形成原核信号识别颗粒（SRP），这是一种高度保守的核糖核蛋白复合物，对蛋白质分泌至关重要。它还能独立结合核糖体中的延伸因子G（EF-G），并在一部分易位事件中发挥作用，这种作用是短暂的，但对细胞存活是必需的。获得了三种不同构建体的晶体，这些构建体包含4.5S RNA的保守结构域IV，其中含有与Ffh和EF-G的识别元件。在低温冷却条件下收集了两种晶体形式的原生X射线衍射数据。最佳晶体是一个45个核苷酸的构建体，使用同步辐射各向异性地衍射到2.6埃分辨率，属于空间群P3(2)21，晶胞参数a = b = 69.1，c = 84.6埃，每个不对称单元有一个RNA分子。