A CONSERVED SECONDARY STRUCTURAL MOTIF IN 23S RIBOSOMAL-RNA DEFINES THE SITE OF INTERACTION OF AMICETIN, A UNIVERSAL INHIBITOR OF PEPTIDE-BOND FORMATION

The binding site and probable site of action have been determined for the universal antibiotic amicetin which inhibits peptide bond formatio n. Evidence from in vivo mutants, site-directed mutations and chemical footprinting all implicate a highly conserved moth in the secondary s tructure of the 23S-like rRNA close to the central circle of domain V. We infer that this motif lies at, or close to, the catalytic site in the peptidyl transfer centre. The binding site of amicetin is the firs t of a group of functionally related hexose-cytosine inhibitors to be localized on the ribosome.