4UHK

Crystal structure of the receiver domain of CpxR from E. coli (phosphorylated)

4UHK の概要

• エントリーDOI: 10.2210/pdb4uhk/pdb
• 関連するPDBエントリー: 4UHJ 4UHS 4UHT
• 分子名称: TRANSCRIPTIONAL REGULATORY PROTEIN CPXR, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: transcription
• 由来する生物種: ESCHERICHIA COLI
• 細胞内の位置: Cytoplasm : P0AE88
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 46998.62

構造登録者

Mechaly, A.E.,Alzari, P.M.A. (登録日: 2015-03-24, 公開日: 2016-04-13, 最終更新日: 2017-06-21)

主引用文献

Mechaly, A.E.,Soto Diaz, S.,Sassoon, N.,Buschiazzo, A.,Betton, J.M.,Alzari, P.M.
Structural Coupling between Autokinase and Phosphotransferase Reactions in a Bacterial Histidine Kinase.
Structure, 25:939-944.e3, 2017

PubMed Abstract: Bacterial two-component systems consist of a sensor histidine kinase (HK) and a response regulator (RR). HKs are homodimers that catalyze the autophosphorylation of a histidine residue and the subsequent phosphoryl transfer to its RR partner, triggering an adaptive response. How the HK autokinase and phosphotransferase activities are coordinated remains unclear. Here, we report X-ray structures of the prototypical HK CpxA trapped as a hemi-phosphorylated dimer, and of the receiver domain from the RR partner, CpxR. Our results reveal that the two catalytic reactions can occur simultaneously, one in each protomer of the asymmetric CpxA dimer. Furthermore, the increase of autokinase activity in the presence of phosphotransfer-impaired CpxR put forward the idea of an allosteric switching mechanism, according to which CpxR binding to one CpxA protomer triggers autophosphorylation in the second protomer. The ensuing dynamical model provides a mechanistic explanation of how HKs can efficiently orchestrate two catalytic reactions involving large-scale protein motions.

PubMed: 28552574
DOI: 10.1016/j.str.2017.04.011

実験手法

X-RAY DIFFRACTION (2.6 Å)