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 indirect methods. Only one residue was found, at position 516. This site is at the 5'-end of one of the three most highly conserved long sequences of this RNA molecule. A number of experimental findings have strongly implicated this loop in the fidelity of codon recognition by A-site bound tRNA. By virtue of its location, we suggest that psi 516 may also play a role in maintaining the fidelity of protein synthesis.