A Study on the Secondary Structure of the Metalloregulatory Protein CueR: Effect of pH, Metal Ions and DNA

Balogh, Ria K. and Németh, Eszter and Jones, Nykola C. and Hoffmann, Søren Vrønning and Jancsó, Attila and Gyurcsik, Béla (2021) A Study on the Secondary Structure of the Metalloregulatory Protein CueR: Effect of pH, Metal Ions and DNA. EUROPEAN BIOPHYSICS JOURNAL : WITH BIOPHYSICS LETTERS, 50 (3-4). pp. 491-500. ISSN 0175-7571 (print); 1432-1017 (online)

Text 52_Balogh_EurBiophysJ_2021_50_491.pdf Restricted to Repository staff only Download (1MB)

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 efect of change in pH, temperature, and the presence of specifc or non-specifc 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.

Actions (login required)

Edit Item