Pleiotropic effects of mutations at positions 13 and 914 inEscherichia coli16S ribosomal RNA

Abstract

Mutations at position 13 or 914 of Escherichia coli 16S ribosomal RNA exert pleiotropic effects on protein synthesis. They interfere with the binding of streptomycin, a translational miscoding drug, to the ribosomes. They increase translational fidelity, and this effect can be related to a perturbation of the higher order structure of the 530 stem–loop, a key region for tRNA selection. In contrast, the structure of the decoding center is not perturbed. The mutations also affect translational initiation, slowing down the formation of the 30S initiation complex. This effect can be related to a destabilization of the pseudoknot helix (17–19/916–918), at the convergence of the three major domains of 16S ribosomal RNA.Key words: ribosomal RNA, translational accuracy, translational initiation.