Bacterial 30S ribosomal subunit 16S rRNA decoding center (16S rRNA decoding center)

The bacterial 30S ribosomal subunit 16S rRNA decoding center is a critical functional region within the small ribosomal subunit responsible for ensuring the fidelity of protein synthesis. Located at the aminoacyl-tRNA binding site (A-site), this center monitors the base-pairing between the mRNA codon and the tRNA anticodon [PubMed: 11130709]. When a correct match is identified, conformational changes in the 16S rRNA—specifically the flipping out of residues A1492 and A1493—trigger the incorporation of the amino acid into the growing polypeptide chain [Nature: 407, 340–348 (2000)]. Because of its essential role in translation, it is a primary target for several classes of antibiotics, most notably aminoglycosides and tetracyclines [PubMed: 11553334]. These drugs bind to the decoding center to either induce misreading of the mRNA or physically block tRNA entry, ultimately leading to bacterial cell death or growth inhibition [PubMed: 11130710]. Due to its high conservation in bacteria and structural divergence from the eukaryotic 18S rRNA, it serves as a key site for selective antimicrobial action [StatPearls: NBK541077].

Other names

16S rRNA A-site30S decoding siteAminoacyl-tRNA binding siteDecoding region of 16S rRNA30S A-site

Aminoglycosides bind to the A-site of the 16S rRNA, inducing a conformational change in residues A1492 and A1493 that mimics a correct codon-anticodon match, leading to mistranslation and bacterial cell death [PubMed: 11553334]. Tetracyclines bind to the same region to sterically block the entry of aminoacyl-tRNA into the A-site, thereby inhibiting protein synthesis [PubMed: 11130710].