The involvement of protein L16 on ribosomal peptidyl transferase activity

Radioactive ribosomes from Escherichia coli were treated with increasing concentrations of NH4Cl in the presence of 50% ethanol. The resulting particles were tested for peptidyl transferase activity as well as for the binding of (U)C-A-C-C-A-Leu-Ac, (U)C-A-C-C-A-Leu, chloramphenicol, lincomycin and erythromycin. At the same time the proteins present in the particles were quantitatively estimated and the amount of each related to the residual activity displayed by the treated ribosomes. It was found that the loss of protein L16 closely paralleled the inactivation of the particles implying an important role for this protein in the structure of the peptidyl transferase center.