Peptidyl transferase center of the 50S ribosomal subunit (PTC)

The peptidyl transferase center of the 50S ribosomal subunit is a highly conserved ribozyme located within domain V of the 23S ribosomal RNA in prokaryotes (or 28S rRNA in eukaryotes), which plays a crucial catalytic role in protein synthesis by facilitating peptide bond formation between adjacent amino acids during translation and catalyzing peptidyl-tRNA hydrolysis during translation termination[1][2][3][4]. The PTC is composed almost entirely of ribosomal RNA, with minimal direct input from ribosomal proteins in catalysis. It forms the core of the large ribosomal subunit’s active site, engaging with the acceptor ends of A- and P-site tRNAs to correctly orient the reactants[2][3]. Due to its essential and universal function, the PTC is the target of several major classes of antibiotics, which inhibit protein synthesis by binding to this region; resistance mutations in the PTC are clinically significant in the treatment of bacterial infections[4][5]. The importance and evolutionary ancient nature of the PTC also make it a focus of origin-of-life studies[1].

Other names

Peptidyl transferase centerPeptidyl transferase sitePT centerPTC of 23S ribosomal RNA (in prokaryotes)PTC of 28S ribosomal RNA (in eukaryotes)

Inhibition of peptide bond formation by binding to the PTC; Inhibition of peptide-tRNA release by binding to the PTC; Induction of stalling or misreading during translation by interfering with tRNA positioning; Allosteric modulation of ribosomal activity