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

The 23S ribosomal RNA (rRNA) peptidyl transferase center (PTC) is the catalytic core of the bacterial 50S ribosomal subunit, functioning as a ribozyme that facilitates peptide bond formation (Polacek & Mankin, 2005, Crit Rev Biochem Mol Biol). It plays a fundamental role in translation by orienting the 3' ends of A-site and P-site tRNAs to allow the nucleophilic attack of the aminoacyl-tRNA on the peptidyl-tRNA. Due to its vital role in bacterial growth and its structural divergence from eukaryotic cytoplasmic ribosomes, the PTC is a major target for diverse classes of antibiotics, including oxazolidinones, macrolides, and lincosamides (Wilson, 2014, Cold Spring Harb Perspect Med). These agents interfere with protein synthesis by either directly inhibiting the peptidyl transferase reaction or by sterically hindering the passage of the growing polypeptide chain through the exit tunnel. Clinical challenges associated with targeting the PTC include the emergence of resistance through rRNA methylation or mutations and potential off-target effects on human mitochondrial ribosomes (Vester & Douthwaite, 2001, Antimicrob Agents Chemother). Consequently, the PTC remains a focal point for the design of novel antimicrobial agents aimed at overcoming drug-resistant pathogens.

Other names

Peptidyl transferase center50S ribosomal subunit peptidyl transferase center23S rRNA PTCRibozyme centerDomain V of 23S rRNA

Inhibition of bacterial protein synthesis by binding to the 23S rRNA within the 50S ribosomal subunit, thereby blocking peptide bond formation or obstructing the nascent peptide exit tunnel (Wilson, 2014, Cold Spring Harb Perspect Med).