The TFE-induced transient native-like structure of the intrinsically disordered σ₄⁷⁰ domain of Escherichia coli RNA polymerase

Eur Biophys J. 2014 Dec;43(12):581-94. doi: 10.1007/s00249-014-0987-4. Epub 2014 Sep 27.

Abstract

The transient folding of domain 4 of an E. coli RNA polymerase σ⁷⁰ subunit (rECσ₄⁷⁰) induced by an increasing concentration of 2,2,2-trifluoroethanol (TFE) in an aqueous solution was monitored by means of CD and heteronuclear NMR spectroscopy. NMR data, collected at a 30% TFE, allowed the estimation of the population of a locally folded rECσ₄⁷⁰ structure (CSI descriptors) and of local backbone dynamics ((15)N relaxation). The spontaneous organization of the helical regions of the initially unfolded protein into a TFE-induced 3D structure was revealed from structural constraints deduced from (15)N- to (13)C-edited NOESY spectra. In accordance with all the applied criteria, three highly populated α-helical regions, separated by much more flexible fragments, form a transient HLHTH motif resembling those found in PDB structures resolved for homologous proteins. All the data taken together demonstrate that TFE induces a transient native-like structure in the intrinsically disordered protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • DNA-Directed RNA Polymerases / chemistry*
  • DNA-Directed RNA Polymerases / metabolism
  • Dose-Response Relationship, Drug
  • Escherichia coli / enzymology*
  • Intrinsically Disordered Proteins / chemistry*
  • Intrinsically Disordered Proteins / metabolism
  • Molecular Dynamics Simulation
  • Movement / drug effects
  • Protein Folding / drug effects
  • Protein Structure, Tertiary / drug effects
  • Trifluoroethanol / pharmacology*

Substances

  • Intrinsically Disordered Proteins
  • Trifluoroethanol
  • DNA-Directed RNA Polymerases