28S ribosomal RNA peptidyl transferase center (28S rRNA PTC) (28S rRNA PTC)

The 28S ribosomal RNA (rRNA) peptidyl transferase center (PTC) is the catalytic core of the eukaryotic 60S ribosomal subunit, functioning as a ribozyme to facilitate peptide bond formation during protein translation (NCBI, 2023). Located within the highly conserved V domain of the 28S rRNA, it is responsible for the fundamental chemical reaction of life: the synthesis of proteins from amino acids. This site is a major target for Ribosome-Inactivating Proteins (RIPs) such as ricin, abrin, and Shiga toxins, which irreversibly inactivate the ribosome by depurinating a specific adenine residue in the sarcin/ricin loop (PubMed, 2021). In therapeutic development, the PTC is targeted by immunotoxins designed to kill malignant cells by halting their protein production. However, because the 28S rRNA is present in all eukaryotic cells, drugs targeting this site must be precisely delivered to avoid severe systemic toxicity. Understanding the PTC's structure is also vital for addressing ribosomopathies and certain viral infections that hijack the host's translational machinery (Nature, 2020).

Other names

Peptidyl transferase centerPTC28S rRNA catalytic siteLarge ribosomal subunit active site

Inhibition of protein synthesis via N-glycosidase activity on the sarcin/ricin loop or steric hindrance of the peptidyl transferase reaction (PubMed, 2021).