The crystal structure of a heptameric archaeal Sm protein: Implications for the eukaryotic snRNP core

被引：93

作者：

Mura, C

Cascio, D

Sawaya, MR

Eisenberg, DS

机构：

[1] Univ Calif Los Angeles, Dept Energy Lab Struct Biol & Mol Med, Inst Mol Biol, Los Angeles, CA 90095 USA

[2] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 2001年 / 98卷 / 10期

关键词：

D O I：

10.1073/pnas.091102298

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Sm proteins form the core of small nuclear ribonucleoprotein particles (snRNPs), making them key components of several mRNA-processing assemblies, including the spliceosome. We report the 1.75-Angstrom crystal structure of SmAP, an Sm-like archaeal protein that forms a heptameric ring perforated by a cationic pore. In addition to providing direct evidence for such an assembly in eukaryotic snRNPs, this structure (i) shows that SmAP homodimers are structurally similar to human Sm heterodimers, (ii) supports a gene duplication model of Sm protein evolution, and (iii) offers a model of SmAP bound to single-stranded RNA (ssRNA) that explains Sm binding-site specificity. The pronounced electrostatic asymmetry of the SmAP surface imparts directionality to putative SmAP-RNA interactions.

引用

页码：5532 / 5537

页数：6

共 37 条

[1] A doughnut-shaped heteromer of human Sm-like proteins binds to the 3′-end of U6 snRNA, thereby facilitating U4/U6 duplex formation in vitro [J].