Bacterial ribosome A-site RNA

Bacterial ribosome A-site RNA refers to a highly conserved region within the 16S ribosomal RNA (rRNA) of the small (30S) subunit of the bacterial ribosome that serves as the aminoacyl-tRNA (A) binding site. This site is critical for ensuring the accuracy (fidelity) of translation by facilitating correct codon-anticodon pairing between mRNA and incoming aminoacyl-tRNA[2][6]. The A-site's structure features bulged nucleotides (notably A1492 and A1493 in E. coli numbering) that flip out to inspect codon-anticodon pairing, switching between 'off' and 'on' conformational states to regulate translation[2]. The A-site is a prominent target for several classes of antibiotics—including aminoglycosides and tetracyclines—which bind specifically to this RNA pocket, disrupting normal translation, promoting miscoding, or preventing tRNA binding[4][5][6]. The essential function and unique structural features of the bacterial A-site make it one of the most validated and exploited targets for antibacterial drug development, although conserved elements in eukaryotic and mitochondrial ribosomes present safety concerns regarding off-target effects and toxicity[4][5][6].

Other names

Ribosomal A-site RNADecoding center A-site RNA16S rRNA A-siteAminoacyl-tRNA acceptor site

Inhibition of protein synthesis via binding to the A-site and disruption of decoding (aminoglycosides promote misreading or block translocation) Blockage of tRNA binding (tetracyclines prevent aminoacyl-tRNA from accessing the A-site)