Microcalorimetric study of elongation factor Tu from Thermus thermophilus in nucleotide-free, GDP and GTP forms and in the presence of elongation factor Ts

Biochim Biophys Acta. 2002 Apr 29;1596(2):357-65. doi: 10.1016/s0167-4838(02)00225-x.

Abstract

Elongation factor (EF) Tu undergoes profound nucleotide-dependent conformational changes in its functional cycle. The thermodynamic parameters of the different Thermus thermophilus EF-Tu forms, its domains I, II/III and III, were determined by microcalorimetry. Thermal transitions of the EF-Tu.GDP and EF-Tu.guanosine-5'-[beta,gamma-imido]triphosphate have a cooperative two-state character. Nucleotide removal affected the cooperativity of the thermal transition of EF-Tu. Microcalorimetric measurements of nucleotide-free EF-Tu and its separated domains showed that domains II/III have the main stabilizing role for the whole protein. Despite the fact that strong interactions between elongation factors Tu and Ts from T. thermophilus at 20 degrees C exist, the thermal transition of neither protein in the complex was significantly affected.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calorimetry, Differential Scanning
  • Guanosine Diphosphate / chemistry
  • Guanosine Triphosphate / chemistry
  • Peptide Elongation Factor Tu / chemistry*
  • Peptide Elongation Factors / chemistry
  • Temperature
  • Thermodynamics
  • Thermus thermophilus / metabolism*

Substances

  • Peptide Elongation Factors
  • elongation factor Ts
  • Guanosine Diphosphate
  • Guanosine Triphosphate
  • Peptide Elongation Factor Tu