4D6X

Crystal structure of the receiver domain of NtrX from Brucella abortus

4D6X の概要

• エントリーDOI: 10.2210/pdb4d6x/pdb
• 分子名称: BACTERIAL REGULATORY, FIS FAMILY PROTEIN, IMIDAZOLE (3 entities in total)
• 機能のキーワード: signaling protein, brucellosis, two-component system, response regulator, rec domain, microaerobisis
• 由来する生物種: BRUCELLA ABORTUS
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 65537.62

構造登録者

Klinke, S.,Fernandez, I.,Carrica, M.C.,Otero, L.H.,Goldbaum, F.A. (登録日: 2014-11-18, 公開日: 2015-07-08, 最終更新日: 2023-12-20)

主引用文献

Fernandez, I.,Otero, L.H.,Klinke, S.,Carrica, M.C.,Goldbaum, F.A.
Snapshots of Conformational Changes Shed Light Into the Ntrx Receiver Domain Signal Transduction Mechanism
J.Mol.Biol., 427:3258-, 2015

PubMed Abstract: Brucella abortus is an important pathogenic bacterium that has to overcome oxygen deficiency in order to achieve a successful infection. Previously, we proved that a two-component system formed by the histidine kinase NtrY and the response regulator NtrX is essential to achieve an adaptive response to low oxygen tension conditions. Even though the relevance of this signaling pathway has already been demonstrated in other microorganisms, its molecular activation mechanism has not yet been described in detail. In this article, we report the first crystal structures from different conformations of the NtrX receiver domain from B. abortus, and we propose a sequence of events to explain the structural rearrangements along the activation process. The analysis of the structures obtained in the presence of the phosphoryl group analog beryllofluoride led us to postulate that changes in the interface formed by the α4 helix and the β5 strand are important for the activation, producing a reorientation of the α5 helix. Also, a biochemical characterization of the NtrX receiver domain enzymatic activities was performed, describing its autophosphorylation and autodephosphorylation kinetics. Finally, the role of H85, an important residue, was addressed by site-directed mutagenesis. Overall, these results provide significant structural basis for understanding the response regulator activation in this bacterial two-component system.

PubMed: 26113057
DOI: 10.1016/J.JMB.2015.06.010

実験手法

X-RAY DIFFRACTION (2.11 Å)