THE SINGLE PSEUDOURIDINE RESIDUE IN ESCHERICHIA-COLI 16S RNA IS LOCATED AT POSITION-516

The number and location of pseudouridine residues in Escherichia coli 16S ribosomal RNA has been determined by a combination of direct and i ndirect methods. Only one residue was found, at position 516. This sit e is at the 5'-end of one of the three most highly conserved long sequ ences of this RNA molecule. A number of experimental findings have str ongly implicated this loop in the fidelity of codon recognition by A-s ite bound tRNA. By virtue of its location, we suggest that Psi 516 may also play a role in maintaining the fidelity of protein synthesis.