Bacterial 30S ribosomal subunit (16S rRNA A-site and ribosomal protein S12) (30S A-site/S12)

The bacterial 30S ribosomal subunit, specifically the 16S rRNA A-site and its associated protein S12, constitutes the essential decoding center of the bacterial translation machinery (Carter et al., 2000, Nature). This complex is responsible for the accurate selection of aminoacyl-tRNA molecules based on the mRNA codon sequence, a process vital for protein synthesis (Ogle et al., 2001, Science). Ribosomal protein S12 (rpsL) is crucial for maintaining the fidelity of this process, as it stabilizes the "closed" conformation of the 30S subunit during cognate tRNA recognition (UniProt P0A7M2). This site is the primary target for aminoglycoside antibiotics, such as streptomycin and gentamicin, which bind to the A-site and induce conformational changes that lead to mRNA misreading and the production of aberrant proteins (StatPearls, 2023). These disruptions are bactericidal, making the 30S A-site/S12 complex a critical target for treating severe infections caused by Gram-negative bacteria and Mycobacterium tuberculosis (PubMed: 11557144). Resistance often arises through mutations in the rpsL gene or the 16S rRNA, which decrease drug affinity while potentially altering translational speed and accuracy (PubMed: 10760218).

Other names

Decoding center16S rRNA A-siterpsL-16S rRNA complexAminoacyl-tRNA binding site30S decoding site

Inhibition of protein synthesis through the induction of mRNA misreading and the stabilization of the aminoacyl-tRNA in the A-site, which prevents effective translocation.