Bacterial 16S ribosomal RNA decoding site (A-site) (16S rRNA A-site)

The bacterial 16S ribosomal RNA (rRNA) A-site, located within the 30S small ribosomal subunit, is the essential decoding center responsible for ensuring the accuracy of protein synthesis (Vicens & Westhof, 2003, ChemBioChem). During translation, this site facilitates the specific interaction between the mRNA codon and the corresponding aminoacyl-tRNA anticodon (Ogle et al., 2001, Science). It is a clinically significant therapeutic target for several classes of antibiotics, most notably aminoglycosides and tetracyclines (StatPearls, 2023). Aminoglycosides bind to the A-site's internal loop, stabilizing an 'active' conformation that allows non-cognate tRNAs to be accepted, resulting in lethal mistranslation (PubMed, PMID: 11588250). Tetracyclines, conversely, sterically hinder the binding of aminoacyl-tRNA to the A-site, thereby halting peptide chain elongation (Chopra & Roberts, 2001, Microbiol Mol Biol Rev). Because of the structural similarity between bacterial 16S rRNA and human mitochondrial 12S rRNA, drugs targeting this site can sometimes cause side effects such as ototoxicity and nephrotoxicity (Guan et al., 2000, Hum Mol Genet).

Other names

16S rRNA aminoacyl-tRNA site30S ribosomal subunit A-siteBacterial decoding region16S rRNA decoding center

Inhibition of bacterial protein synthesis through the induction of mRNA misreading or the physical blockade of aminoacyl-tRNA binding to the decoding center.