Eukaryotic ribosomal aminoacyl-tRNA site (A-site) (Ribosomal A-site)

The eukaryotic ribosome A-site (aminoacyl site) is a specialized region within the 40S ribosomal subunit responsible for the decoding of genetic information during translation (NCBI, PMC3513837). It serves as the entry point for aminoacyl-tRNA molecules, which must match the mRNA codon currently positioned in the site to proceed with peptide bond formation. While historically viewed as a target for antibacterial agents that exploit differences between prokaryotic and eukaryotic ribosomes, the eukaryotic A-site has emerged as a therapeutic target for treating genetic disorders caused by nonsense mutations (PubMed, 22403077). Small molecules like aminoglycosides and ataluren bind to this site to induce "translational read-through," allowing the ribosome to bypass premature stop codons and produce functional, full-length proteins (Nature, 447(7140)). This mechanism is currently being explored for conditions such as cystic fibrosis and Duchenne muscular dystrophy (Journal of Medicinal Chemistry, 2017). However, targeting this site requires careful management of potential toxicities, including nephrotoxicity and ototoxicity, which can arise from off-target effects on mitochondrial ribosomes or general translation fidelity.

Other names

Decoding centerAminoacyl site18S rRNA A-siteRibosomal A-site

Induction of translational read-through of premature stop codons (nonsense suppression) by binding to the decoding center and altering the ribosome's ability to distinguish between cognate and near-cognate tRNAs (PubMed, 22403077).