Small ribosomal subunit protein uS4 (uS4)

Small ribosomal subunit protein uS4 is a highly conserved structural component of the small subunit of the ribosome. In prokaryotes like Escherichia coli, it is known as 30S ribosomal protein S4 and plays a critical role in initiating assembly by binding directly to 16S rRNA and nucleating formation of the body of the 30S subunit. It also participates in maintaining translational fidelity and regulating translation initiation. In eukaryotes, homologous proteins exist with similar functions but different nomenclature (e.g., RPS9). The bacterial form is an established target for several classes of antibiotics that inhibit translation by interfering with its function or structure.

Other names

30S ribosomal protein S4 (in prokaryotes, especially Escherichia coli)RPS9 (in eukaryotes, including humans and mice)ramA (gene synonym in E. coli)

Drugs such as tetracyclines bind to the small ribosomal subunit protein uS4 or its associated rRNA, inhibiting bacterial translation and thus blocking protein synthesis.