C-terminal Cysteines of CueR Act as Auxiliary Metal Site Ligands upon HgII Binding—A Mechanism To Prevent Transcriptional Activation by Divalent Metal Ions?

Ria K. Balogh, Béla Gyurcsik, Éva Hunyadi-Gulyás, Juliana Schell, Peter W. Thulstrup, Lars Hemmingsen, Attila Jancsó

Research output: Contribution to journalArticle

Abstract

Intracellular CuI is controlled by the transcriptional regulator CueR, which effectively discriminates between monovalent and divalent metal ions. It is intriguing that HgII does not activate transcription, as bis-thiolate metal sites exhibit high affinity for HgII. Here the binding of HgII to CueR and a truncated variant, ΔC7-CueR, without the last 7 amino acids at the C-terminus including a conserved CCHH motif is explored. ESI-MS demonstrates that up to two HgII bind to CueR, while ΔC7-CueR accommodates only one HgII. 199mHg PAC and UV absorption spectroscopy indicate HgS2 structure at both the functional and the CCHH metal site. However, at sub-equimolar concentrations of HgII at pH 8.0, the metal binding site displays an equilibrium between HgS2 and HgS3, involving cysteines from both sites. We hypothesize that the C-terminal CCHH motif provides auxiliary ligands that coordinate to HgII and thereby prevents activation of transcription.

Original languageEnglish
JournalChemistry - A European Journal
DOIs
Publication statusAccepted/In press - Jan 1 2019

Fingerprint

Metal ions
Cysteine
Metals
Chemical activation
Ligands
Transcription
Binding sites
Ultraviolet spectroscopy
Absorption spectroscopy
Amino acids
Binding Sites
Amino Acids

Keywords

  • coordination modes
  • CueR metalloregulatory protein
  • mercury
  • metal ion selectivity
  • perturbed angular correlation (PAC) spectroscopy

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

Cite this

@article{49ef5329a2844a0599f2e3ded129e006,
title = "C-terminal Cysteines of CueR Act as Auxiliary Metal Site Ligands upon HgII Binding—A Mechanism To Prevent Transcriptional Activation by Divalent Metal Ions?",
abstract = "Intracellular CuI is controlled by the transcriptional regulator CueR, which effectively discriminates between monovalent and divalent metal ions. It is intriguing that HgII does not activate transcription, as bis-thiolate metal sites exhibit high affinity for HgII. Here the binding of HgII to CueR and a truncated variant, ΔC7-CueR, without the last 7 amino acids at the C-terminus including a conserved CCHH motif is explored. ESI-MS demonstrates that up to two HgII bind to CueR, while ΔC7-CueR accommodates only one HgII. 199mHg PAC and UV absorption spectroscopy indicate HgS2 structure at both the functional and the CCHH metal site. However, at sub-equimolar concentrations of HgII at pH 8.0, the metal binding site displays an equilibrium between HgS2 and HgS3, involving cysteines from both sites. We hypothesize that the C-terminal CCHH motif provides auxiliary ligands that coordinate to HgII and thereby prevents activation of transcription.",
keywords = "coordination modes, CueR metalloregulatory protein, mercury, metal ion selectivity, perturbed angular correlation (PAC) spectroscopy",
author = "Balogh, {Ria K.} and B{\'e}la Gyurcsik and {\'E}va Hunyadi-Guly{\'a}s and Juliana Schell and Thulstrup, {Peter W.} and Lars Hemmingsen and Attila Jancs{\'o}",
year = "2019",
month = "1",
day = "1",
doi = "10.1002/chem.201902940",
language = "English",
journal = "Chemistry - A European Journal",
issn = "0947-6539",
publisher = "Wiley-VCH Verlag",

}

TY - JOUR

T1 - C-terminal Cysteines of CueR Act as Auxiliary Metal Site Ligands upon HgII Binding—A Mechanism To Prevent Transcriptional Activation by Divalent Metal Ions?

AU - Balogh, Ria K.

AU - Gyurcsik, Béla

AU - Hunyadi-Gulyás, Éva

AU - Schell, Juliana

AU - Thulstrup, Peter W.

AU - Hemmingsen, Lars

AU - Jancsó, Attila

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Intracellular CuI is controlled by the transcriptional regulator CueR, which effectively discriminates between monovalent and divalent metal ions. It is intriguing that HgII does not activate transcription, as bis-thiolate metal sites exhibit high affinity for HgII. Here the binding of HgII to CueR and a truncated variant, ΔC7-CueR, without the last 7 amino acids at the C-terminus including a conserved CCHH motif is explored. ESI-MS demonstrates that up to two HgII bind to CueR, while ΔC7-CueR accommodates only one HgII. 199mHg PAC and UV absorption spectroscopy indicate HgS2 structure at both the functional and the CCHH metal site. However, at sub-equimolar concentrations of HgII at pH 8.0, the metal binding site displays an equilibrium between HgS2 and HgS3, involving cysteines from both sites. We hypothesize that the C-terminal CCHH motif provides auxiliary ligands that coordinate to HgII and thereby prevents activation of transcription.

AB - Intracellular CuI is controlled by the transcriptional regulator CueR, which effectively discriminates between monovalent and divalent metal ions. It is intriguing that HgII does not activate transcription, as bis-thiolate metal sites exhibit high affinity for HgII. Here the binding of HgII to CueR and a truncated variant, ΔC7-CueR, without the last 7 amino acids at the C-terminus including a conserved CCHH motif is explored. ESI-MS demonstrates that up to two HgII bind to CueR, while ΔC7-CueR accommodates only one HgII. 199mHg PAC and UV absorption spectroscopy indicate HgS2 structure at both the functional and the CCHH metal site. However, at sub-equimolar concentrations of HgII at pH 8.0, the metal binding site displays an equilibrium between HgS2 and HgS3, involving cysteines from both sites. We hypothesize that the C-terminal CCHH motif provides auxiliary ligands that coordinate to HgII and thereby prevents activation of transcription.

KW - coordination modes

KW - CueR metalloregulatory protein

KW - mercury

KW - metal ion selectivity

KW - perturbed angular correlation (PAC) spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85074420724&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85074420724&partnerID=8YFLogxK

U2 - 10.1002/chem.201902940

DO - 10.1002/chem.201902940

M3 - Article

AN - SCOPUS:85074420724

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

ER -