3G7Z

CcdB dimer in complex with two C-terminal CcdA domains

3G7Z の概要

• エントリーDOI: 10.2210/pdb3g7z/pdb
• 関連するPDBエントリー: 1VUB 1X75 2adl 2h3a 2VUB 2ZOR 3VUB 4VUB
• 分子名称: Cytotoxic protein ccdB, Protein ccdA (3 entities in total)
• 機能のキーワード: alpha+beta, sh3 domain, intrinsically disordered, toxin-toxin repressor complex, toxin/toxin repressor
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 32196.67

構造登録者

De Jonge, N.,Loris, R.,Garcia-Pino, A.,Buts, L. (登録日: 2009-02-11, 公開日: 2009-08-11, 最終更新日: 2023-09-06)

主引用文献

De Jonge, N.,Garcia-Pino, A.,Buts, L.,Haesaerts, S.,Charlier, D.,Zangger, K.,Wyns, L.,De Greve, H.,Loris, R.
Rejuvenation of CcdB-Poisoned Gyrase by an Intrinsically Disordered Protein Domain.
Mol.Cell, 35:154-163, 2009

PubMed Abstract: Toxin-antitoxin modules are small regulatory circuits that ensure survival of bacterial populations under challenging environmental conditions. The ccd toxin-antitoxin module on the F plasmid codes for the toxin CcdB and its antitoxin CcdA. CcdB poisons gyrase while CcdA actively dissociates CcdB:gyrase complexes in a process called rejuvenation. The CcdA:CcdB ratio modulates autorepression of the ccd operon. The mechanisms behind both rejuvenation and regulation of expression are poorly understood. We show that CcdA binds consecutively to two partially overlapping sites on CcdB, which differ in affinity by six orders of magnitude. The first, picomolar affinity interaction triggers a conformational change in CcdB that initiates the dissociation of CcdB:gyrase complexes by an allosteric segmental binding mechanism. The second, micromolar affinity binding event regulates expression of the ccd operon. Both functions of CcdA, rejuvenation and autoregulation, are mechanistically intertwined and depend crucially on the intrinsically disordered nature of the CcdA C-terminal domain.

PubMed: 19647513
DOI: 10.1016/j.molcel.2009.05.025

実験手法

X-RAY DIFFRACTION (2.351 Å)