Thermodynamic analysis reveals that GTP binding affects the interaction between the α- and γ-subunits of translation initiation factor 2

Makoto Nakakido, Yoshikazu Tanaka, Masaaki Sokabe, Kouhei Tsumoto

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Eukaryotic and archaeal translation initiation factors 2, heterotrimers that consist of α-, β-, and γ-subunits, deliver methionylated initiator tRNA to a small ribosomal subunit in a manner that depends on GTP. To evaluate correlation of the function and association of the subunits, we used isothermal titration calorimetry to analyze the thermodynamics of the interactions between the α- and γ-subunits in the presence or absence of a nonhydrolyzable GTP analog or GDP. The α-subunits bound to the γ-subunit with large heat capacity change (ΔCp) values. The ΔH and ΔCp values for the interaction between the α- and γ-subunits varied in the presence of the GTP analog but not in the presence of GDP. These results suggest that the binding of both the α-subunit and GTP changes the conformation of the switch region of the γ-subunit and increases the affinity of the γ-subunit for tRNA.

Original languageEnglish
Pages (from-to)596-599
Number of pages4
JournalBiochemical and biophysical research communications
Volume371
Issue number4
DOIs
Publication statusPublished - 2008 Jul 11
Externally publishedYes

Keywords

  • GTP
  • Thermodynamics
  • Translation initiation factor 2
  • tRNA binding

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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