Bacterial 30S ribosomal subunit (30S subunit)

The Bacterial 30S ribosomal subunit is the smaller component of the prokaryotic 70S ribosome, consisting of 16S ribosomal RNA and approximately 21 ribosomal proteins, with a molecular mass of about 0.85 MDa. It plays essential roles in translation by binding messenger RNA (mRNA), decoding the genetic code through codon-anticodon interactions with transfer RNAs (tRNAs), maintaining the mRNA reading frame, and facilitating translocation with the 50S subunit. The subunit recognizes the Shine-Dalgarno sequence upstream of the start codon via its 16S rRNA, binds initiation factors (IF-1, IF-2, IF-3), and positions f-Met-tRNA at the P-site for initiation. Structural studies reveal dynamic domains (head, platform, body) with key proteins like S1 (stabilizing mRNA), uS11, bS21, and interactions with antibiotics that disrupt these processes. In disease, it serves as a primary antibacterial target, as drugs binding the subunit inhibit bacterial protein synthesis without significantly affecting eukaryotic 80S ribosomes. High-resolution cryo-EM and X-ray structures (down to 2 Å) detail rRNA modifications, protein contacts, and drug binding sites, aiding antibiotic design.

Other names

Prokaryotic small ribosomal subunitsmall subunit of the 70S ribosome

Interfere with decoding, interfere with translocation