Open AccessInactivation of 50S Ribosomal Subunits by 2‐Methoxy‐5‐nitrotropone
Author(s) -
Suzuka Iwao
Publication year - 1971
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1971.tb01592.x
Subject(s) - 50s , ribosome , 30s , ribosomal rna , protein subunit , ribosomal protein , chemistry , gtp' , eukaryotic ribosome , biophysics , biochemistry , stereochemistry , crystallography , biology , rna , enzyme , gene
1 Treatment of 50S ribosomal subunits with 2‐methoxy‐5‐nitrotropone results in extensive loss of their ability to synthesize polyphenylalanine, display ribosome‐dependent GTPase activity, or bind GTP to ribosomes. In contrast, 5‐nitrotroponyl 50S subunits are fully active for diphenylalanine synthesis. Thus, 2‐methoxy‐5 nitrotropone‐reactable ribosomal protein groups on the 50S subunit may be associated with translocation activity of ribosomes. 2 Sedimentation analysis of 5‐nitrotroponyl 50S subunits at 0.02 M Mg 2+ shows a slightly faster sedimenting component (54S) and their dimerized form (79S). Furthermore, the particles which are reassociated with 30S and 5‐nitrotroponyl 50S subunits are dissociated into each subunit under conditions of Mg 2+ concentration (5 mM) where most of 30S‐associated control 50S particles are still present as a 70S particle. These results appear to reflect the structural alteration of the 50S subunits caused by the treatment of 2‐methoxy‐5‐nitrotropone.