|
1
|
Balogh RK, Németh E, Jones NC, Hoffmann SV, Jancsó A, Gyurcsik B. A study on the secondary structure of the metalloregulatory protein CueR: effect of pH, metal ions and DNA. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2021; 50:491-500. [PMID: 33907862 DOI: 10.1007/s00249-021-01539-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/13/2021] [Accepted: 04/14/2021] [Indexed: 11/30/2022]
Abstract
The response of CueR towards environmental changes in solution was investigated. CueR is a bacterial metal ion selective transcriptional metalloregulator protein, which controls the concentration of copper ions in the cell. Although several articles have been devoted to the discussion of the structural and functional features of this protein, CueR has not previously been extensively characterized in solution. Here, we studied the effect of change in pH, temperature, and the presence of specific or non-specific binding partners on the secondary structure of CueR with circular dichroism (CD) spectroscopy. A rather peculiar reversible pH-dependent secondary structure transformation was observed, elucidated and supplemented with pKa estimation by PROPKA and CpHMD simulations suggesting an important role of His(76) and His(94) in this process. CD experiments revealed that the presence of DNA prevents this structural switch, suggesting that DNA locks CueR in the α-helical-rich form. In contrast to the non-cognate metal ions HgII, CdII and ZnII, the presence of the cognate AgI ion affects the secondary structure of CueR, most probably by stabilizing the metal ion and DNA-binding domains of the protein.
Collapse
Affiliation(s)
- Ria K Balogh
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged, 6720, Hungary
| | - Eszter Németh
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged, 6720, Hungary.,Institute of Enzymology, Genome Stability Research Group, Research Centre for Natural Sciences, Magyar tudósok körútja 2, Budapest, 1117, Hungary
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000, Aarhus C, Denmark
| | - Søren Vrønning Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000, Aarhus C, Denmark
| | - Attila Jancsó
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged, 6720, Hungary
| | - Béla Gyurcsik
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged, 6720, Hungary.
| |
Collapse
|