targeted_by targeted_by_antibiotic part_of lincosamide antibiotic streptogramin antibiotic streptogramin A antibiotic lincomycin clindamycin targeted_by targeted_by_antibiotic azidamfenicol chloramphenicol phenicol antibiotic thiamphenicol florfenicol pristinamycin IA quinupristin virginiamycin M1 pleuromutilin antibiotic madumycin II griseoviridin dalfopristin pristinamycin IB virginiamycin S2 pristinamycin IC vernamycin C patricin A patricin B ostreogrycin B3 50S ribosomal subunit ribonucleic acid antibiotic sensitive peptidyl transferase (23S rRNA) ARO:3000754 antibiotic_resistance The bacterial 23S rRNA, at the P site of the 50S subunit, has peptidyl transferase activity and is responsible for peptide synthesis and elongation.