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

The bacterial 16S ribosomal RNA decoding A-site is a highly conserved region within the 30S ribosomal subunit essential for the fidelity of genetic translation (Ogle et al., 2001, Science). Its primary biological function is to monitor the complementarity between the mRNA codon and the tRNA anticodon, ensuring that only the correct aminoacyl-tRNA is accepted into the ribosome (Vicens & Westhof, 2001, Structure). This site is the principal pharmacological target for aminoglycoside antibiotics, which bind to the internal loop of the A-site and lock the decoding residues, A1492 and A1493, in an "out" conformation (Magnet & Blanchard, 2005, Chemical Reviews). This interaction causes the ribosome to misread the genetic code, leading to the synthesis of mistranslated, truncated, or non-functional proteins that ultimately compromise the bacterial cell membrane and cause cell death (Kohanski et al., 2007, Cell). Clinically, this target is vital for treating severe infections caused by Gram-negative and some Gram-positive bacteria, although its utility is often limited by the emergence of resistance mechanisms such as 16S rRNA methyltransferases (Doi et al., 2016, Journal of Infection and Chemotherapy).

Other names

16S rRNA decoding site30S A-siteAminoacyl-tRNA binding siteDecoding center

Binding to the 16S rRNA A-site to induce codon misreading and inhibit ribosomal translocation, leading to defective protein synthesis and bacterial cell death (Magnet & Blanchard, 2005, Chemical Reviews).