Characterization of the sensor domain of QseE histidine kinase from Escherichia coli

Kwon Joo Yeo, Jin Wan Park, Eun Hee Kim, Young Ho Jeon, Kwang Yeon Hwang, Hae Kap Cheong

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In enterohemorrhagic Escherichia coli (EHEC), the QseEF two-component system causes attaching and effacing (AE) lesion on epithelial cells. QseE histidine kinase senses the host hormone epinephrine, sulfate, and phosphate; it also regulates QseF response regulator, which activates LEE gene that encodes AE lesion. In order to understand the recognition of ligand molecules and signal transfer mechanism in pathogenic bacteria, structural studies of the sensor domain of QseE of Escherichia coli should be conducted. In this study, we describe the overexpression, purification, and structural and biophysical properties of the sensor domain of QseE. The fusion protein had a 6×His tag at its N-terminus; this protein was overexpressed as inclusion bodies in E. coli BL21 (DE3). The protein was denatured in 7M guanidine hydrochloride and refolded by dialysis. The purification of the refolded protein was carried out using Ni-NTA affinity column and size-exclusion chromatography. Thereafter, the characteristics of the refolded protein were determined from NMR, CD, and MALS spectroscopies. In a pH range of 7.4–5.0, the folded protein existed in a monomeric form with a predominantly helical structure. 1H-15N HSQC NMR spectra shows that approximately 93% backbone amide peaks are detected at pH 5.0, suggesting that the number of backbone signals is sufficient for NMR studies. These data might provide an opportunity for structural and functional studies of the sensor domain of QseE.

Original languageEnglish
Pages (from-to)122-126
Number of pages5
JournalProtein Expression and Purification
Volume126
DOIs
Publication statusPublished - 2016 Oct 1

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Keywords

  • Histidine kinase
  • QseE
  • QseE sensor domain
  • Quorum sensing
  • Refolding

ASJC Scopus subject areas

  • Biotechnology

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