title: The role of ribosomal conformation in protein biosynthesis: the streptomycin-ribosome interaction.
abstract: The role played by ribosomal conformation in codon-anticodon recognition has been studied using streptomycin as a probe, inasmuch as streptomycin is known to cause misreading of the genetic code. Changes in ribosomal structure have been followed by the method of hydrogen-tritium exchange. The results show that streptomycin induces two types of change in the hydrogen exchange pattern. At low molar ratios of streptomycin to ribosomes, a stimulation of the hydrogen exchange rate ("loosening" of ribosomal structure) is observed, with a small inhibition of polypeptide synthesis. As the streptomycin: ribosome ratio is increased, a maximum exchange rate is reached, after which the rate decreases ("tightening" of structure); in this region, inhibition of peptide synthesis increases sharply, and misreading of the code begins. None of these effects is observed with streptomycin-resistant ribosomes.
mesh_terms: D004926:Escherichia coli / Q000378:metabolism; D005815:Genetic Code; D006859:Hydrogen / Q000378:metabolism; D011119:Polynucleotides; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000187:drug effects / Q000502:physiology*; D013307:Streptomycin / Q000378:metabolism* / Q000494:pharmacology; D014316:Tritium; D014500:Uracil Nucleotides
chemical_list: D011119:Polynucleotides; D014500:Uracil Nucleotides; D014316:Tritium; D006859:Hydrogen; D013307:Streptomycin