A MUTATION AT THE UNIVERSALLY CONSERVED POSITION-529 IN ESCHERICHIA-COLI 16S RIBOSOMAL-RNA CREATES A FUNCTIONAL BUT HIGHLY ERROR-PRONE RIBOSOME

A base substitution of G to U was constructed at position 529 in Esche richia coli 16S rRNA. The U529 mutant ribosomes were functional and pr esent on polysomes but were highly error prone and caused a progressiv e loss of cell viability. They displayed elevated levels of readthroug h of stop codons and frameshifting, and an increase in thermal sensiti vity of beta-galactosidase, suggestive of missense errors. These resul ts demonstrate that the universally conserved G529 is involved in tRNA selection at the A site during protein synthesis.