STRUCTURE OF LICL CORE PARTICLES OF 50 S RIBOSOMAL-SUBUNITS FROM ESCHERICHIA-COLI BY ELECTRON-MICROSCOPY

  • 1 January 1978
    • journal article
    • research article
    • Vol. 18 (2), 309-319
Abstract
The structure of 50 S E. coli ribosomal subunits was studied by EM as these particles were gradually depleted of proteins by incubation with 0.5-6.0 M LiCl. Changes observed in the structure of the depleted subunits were correlated with the location of the deleted ribosomal proteins on the control 50 S particle. These changes were particularly striking in the crown region, the site of a considerable number of the proteins necessary for the biological activity of the 50 S subunit. Protein L 16, the first to be removed by the LiCl treatment, was essential for the structural integrity of the large subunit through interactions with ribosomal proteins residing in the left-hand side crest and the interface. Based on EM evidence, a scheme was proposed for the structural changes accompanying the stepwise unfolding of the 50 S E. coli subunit by LiCl.