Effect of salt concentration on TTF-1 HD binding to specific and non-specific DNA sequences

Biochem Biophys Res Commun. 1993 Dec 15;197(2):632-8. doi: 10.1006/bbrc.1993.2526.

Abstract

The Thyroid Transcription factor 1 (TTF-1) recognizes specific DNA sequences by a Homeodomain (TTF-1 HD). The TTF-1 HD DNA-binding properties with both specific and non-specific DNA sequences were investigated. TTF-1 HD exists as a monomer in solution and as a monomer binds DNA. At 75 mM KCl, its relative binding affinity with a specific DNA sequence is about 50 fold higher than with a non-specific DNA sequence. Increase of KCl concentration reduces the apparent binding affinity both to specific and non-specific DNA sequences. However, non-specific binding is more sensitive than specific binding to the increase of salt concentration. When DNA-binding reactions are performed at temperature and salt concentration close to the intracellular environment, TTF-1 HD binds the specific sequence with an affinity at least 1000 fold higher respect to the non-specific sequence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Cattle
  • Chromatography, Gel
  • Cloning, Molecular
  • DNA / metabolism*
  • DNA-Binding Proteins / metabolism*
  • Kinetics
  • Molecular Sequence Data
  • Nuclear Proteins / biosynthesis
  • Nuclear Proteins / isolation & purification
  • Nuclear Proteins / metabolism*
  • Oligodeoxyribonucleotides
  • Osmolar Concentration
  • Potassium Chloride / pharmacology
  • Promoter Regions, Genetic
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Thermodynamics
  • Thyroid Nuclear Factor 1
  • Transcription Factors / biosynthesis
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*

Substances

  • DNA-Binding Proteins
  • Nuclear Proteins
  • Oligodeoxyribonucleotides
  • Recombinant Proteins
  • Thyroid Nuclear Factor 1
  • Transcription Factors
  • Potassium Chloride
  • DNA