Open AccessInfluence of Guanine Nucleotides and Elongation Factors on Interaction of Release Factors with the Ribosome
Author(s) -
Warren P. Tate,
Arthur L. Beaudet,
C. Thomas Caskey
Publication year - 1973
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.70.8.2350
Subject(s) - ribosome , gtpase , reticulocyte , biochemistry , gtp' , elongation factor , ef tu , initiation factor , ribosomal rna , transfer rna , biology , chemistry , rna , enzyme , gene
Release of formylmethionine from the reticulocyte ribosomal substrate, f[3 H]Met-tRNA·ribosome, is promoted by reticulocyte release factor (RF). The initial rate of this reaction is stimulated by GTP but inhibited by GDPCP. Formation of an RF·UA[3 H]A2 ·ribosome complex is a measure of the binding of reticulocyte RF to the ribosome, and the recovery of this complex is increased by GDPCP and, to a lesser extent, GTP. These studies suggest that GTP is involved in the initial association of RF with the ribosome and that hydrolysis of the γ-phosphate of the guanine nucleotide is required at a subsequent rate-limiting step. The ribosomal-dependent fMet-tRNA hydrolysis and GTPase activities of reticulocyte RF are inhibited when elongation factor (EF)-2 is bound to the respective ribosomal substrate in the presence of fusidic acid and GDP. When EF-G is bound to the f[3 H]Met-tRNA·AUG·ribosome substrate with fusidic acid and GDP, the fMet-tRNA hydrolysis activity ofEscherichia coli RF-1 and RF-2 is also inhibited. The binding of reticulocyte RF andE. coli RF-1 or RF-2 to their respective ribosomes is prevented when fusidic acid·EF-2/EF-G·GDP·ribosome complexes are used.