Affinity labeling of the ribonucleic acid component adjacent to the peptidyl recognition center of peptidyl transferase in Escherichia coli ribosomes.

N-Iodacetylphenylalanyl-tRNA was used as an affinity label for localizing the RNA components intimately related to the peptidyl transferase activity of Escherichia coli ribosomesmthis analogue could specifically alkylate a unique nucleotide chain of 23-S RNA. The alkylation was strongly enhanced by poly(U), and was dependent on the presence of both 50- and 30-S subunits; Chloramphenicol inhibited the reaction, wheras blasticidin S stimulated it. The alkylated RNA base was found to be adenine. The nucleotide chain attacked by N-iodoacetylphenylalanyl-tRNA seemed to be localized at or near to the peptidyl recognition center of peptidyl transferase.