Bacterial 70S ribosome (30S subunit decoding center) (30S decoding center)

The bacterial 70S ribosome is a complex ribonucleoprotein machine responsible for protein synthesis, consisting of a large 50S subunit and a small 30S subunit (Ogle et al., 2001, Science). The decoding center, located within the 30S subunit and primarily composed of 16S ribosomal RNA (rRNA), is the site where the fidelity of translation is maintained by ensuring correct codon-anticodon pairing (Ogle et al., 2001, Science). This site is a major therapeutic target for several classes of antibiotics, including aminoglycosides and tetracyclines (Kohanski et al., 2010, Nature Reviews Microbiology). Aminoglycosides bind to the A-site of the 16S rRNA, causing conformational changes that lead to the incorporation of incorrect amino acids and the production of mistranslated proteins (Kohanski et al., 2010, Nature Reviews Microbiology). Tetracyclines sterically block the attachment of aminoacyl-tRNA to the A-site, thereby preventing the elongation of the polypeptide chain (Chopra & Roberts, 2001, Microbiology and Molecular Biology Reviews). Because mitochondrial ribosomes share structural similarities with bacterial ribosomes, drugs targeting this site can sometimes cause host toxicity, such as ototoxicity or nephrotoxicity (Ahmad et al., 2023, StatPearls). Resistance to these drugs often arises through mutations in the 16S rRNA or through the action of aminoglycoside-modifying enzymes (Chopra & Roberts, 2001, Microbiology and Molecular Biology Reviews). Understanding the structural nuances of the decoding center is vital for developing new antibiotics that can overcome emerging bacterial resistance mechanisms.

Other names

30S ribosomal subunitA-site of the 30S subunit16S rRNA decoding siteBacterial decoding centerSmall ribosomal subunit decoding center

Drugs targeting the 30S decoding center primarily inhibit protein synthesis by either physically blocking the binding of aminoacyl-tRNA to the A-site or by inducing conformational changes in the 16S rRNA that lead to the misreading of the genetic code and subsequent production of non-functional or toxic proteins (Kohanski et al., 2010, Nature Reviews Microbiology; Chopra & Roberts, 2001, Microbiology and Molecular Biology Reviews).