Interaction of transfer RNA with 50S ribosomal subunits of Escherichia coli in absence of templates.
The equilibrium constant of a complex of tRNA with the 50S ribosomal subunit was measured in the absence of a template. It was shown that the stability of the complex increases with an increase in the concentration of Mg2+, it decreases with an increase in the concentration of univalent ions, and does not depend on the pH of the medium in the range of 7.0-8.2. Removal of the 3'-terminal nucleoside of tRNA weakens the association approximately 40-fold; the subsequent successive splitting off of another three nucleotides has little effect on the association constant. In 90% 2H2O the stability of the complex increases approximately four-fold, which points to the large contribution of the hydrogen bonds to the free energy of the interaction. The tetranucleotide TphiCG competes slightly with tRNA for sites on the 50S subparticles; this means that the TphiC segment of tRNA does not play an important role in the formation of the complex under investigation.
D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002414:Cations, Monovalent; D003903:Deuterium / Q000494:pharmacology; D004926:Escherichia coli; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology; D009841:Oligonucleotides / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013698:Templates, Genetic; D013816:Thermodynamics
D002414:Cations, Monovalent; D009841:Oligonucleotides; D012343:RNA, Transfer; D003903:Deuterium; D008274:Magnesium