Bacterial 23S ribosomal RNA peptidyl transferase center (PTC) (23S rRNA PTC)

The Bacterial 23S ribosomal RNA peptidyl transferase center (PTC) is the catalytic core of the 50S large ribosomal subunit, serving as the site where peptide bond formation occurs during protein synthesis (Polikanov et al., 2012, PubMed). It is a ribozyme, meaning the catalytic activity is mediated by RNA rather than protein components (Nissen et al., 2000, Science). This site is the primary target for several major classes of antibiotics, including macrolides, oxazolidinones, lincosamides, and chloramphenicol (Wilson, 2014, Nature Reviews Microbiology). These therapeutic agents work by binding to the 23S rRNA, either directly blocking the peptidyl transferase reaction or sterically obstructing the exit tunnel for the growing polypeptide chain (Dunkle et al., 2010, PNAS). Because the PTC is essential for bacterial viability, it is a highly effective target for treating a wide range of bacterial infections (StatPearls, 2023). However, its structural similarity to human mitochondrial ribosomes can lead to off-target effects and clinical safety concerns such as bone marrow suppression (Ames et al., 2002, Antimicrobial Agents and Chemotherapy). Resistance to these drugs often develops through specific mutations in the 23S rRNA or through enzymatic modifications like methylation, which hinder drug binding (Vester & Douthwaite, 2001, Antimicrobial Agents and Chemotherapy).

Other names

Peptidyl transferase centerPTC23S rRNA50S ribosomal subunit catalytic siteRibosomal peptidyltransferase

Inhibition of bacterial protein synthesis by binding to the 23S rRNA within the 50S ribosomal subunit, thereby blocking peptide bond formation or sterically hindering the passage of the nascent peptide chain through the exit tunnel (Wilson, 2014, Nature Reviews Microbiology).