The Crystal Structure of the Intact E. coli ReIBE Toxin-Antitoxin Complex Provides the Structural Basis for Conditional Cooperativity

被引：85

作者：

Boggild, Andreas ^{[1
]}

Sofos, Nicholas ^{[1
]}

Andersen, Kasper R. ^{[1
]}

Feddersen, Ane ^{[1
]}

Easter, Ashley D. ^{[2
]}

Passmore, Lori A. ^{[2
]}

Brodersen, Ditlev E. ^{[1
]}

机构：

[1] Aarhus Univ, Ctr mRNP Biogenesis & Metab, Dept Mol Biol & Genet, DK-8000 Aarhus C, Denmark

[2] MRC Lab Mol Biol, Cambridge CB2 0QH, England

来源：

STRUCTURE | 2012年 / 20卷 / 10期

基金：

新加坡国家研究基金会; 英国医学研究理事会;

关键词：

RELE; TRANSCRIPTION; RECOGNITION; MECHANISM; CLEAVAGE; SYSTEM;

D O I：

10.1016/j.str.2012.08.017

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The bacterial relBE locus encodes a toxin-antitoxin complex in which the toxin, RelE, is capable of cleaving mRNA in the ribosomal A site cotranslationally. The antitoxin, RelB, both binds and inhibits RelE, and regulates transcription through operator binding and conditional cooperativity controlled by RelE. Here, we present the crystal structure of the intact Escherichia coli RelB(2)E(2) complex at 2.8 angstrom resolution, comprising both the RelB-inhibited RelE and the RelB dimerization domain that binds DNA. RelE and RelB associate into a V-shaped heterotetrameric complex with the ribbon-helix-helix (RHH) dimerization domain at the apex. Our structure supports a model in which relO is optimally bound by two adjacent RelB(2)E heterotrimeric units, and is not compatible with concomitant binding of two RelB(2)E(2) heterotetramers. The results thus provide a firm basis for understanding the model of conditional cooperativity at the molecular level.

引用

页码：1641 / 1648

页数：8

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