Small ribosomal subunit protein uS13 (uS13)

Small ribosomal subunit protein uS13 is a conserved structural and functional component of the ribosome's small subunit (40S in eukaryotes, 30S in prokaryotes)[1][5][6]. In humans, it is encoded by the **RPS18** gene and commonly referred to as 40S ribosomal protein S18[1]. uS13 is involved in proper assembly and function of the ribosomal small subunit, playing key roles in *mRNA decoding* and *RNA binding* during translation initiation and elongation[5][6]. In bacteria, uS13 is specifically involved in binding fMet-tRNA, essential for the initiation of protein synthesis[5]. Its position at the top of the head of the small subunit allows it to contact several helices of the ribosomal RNA (16S in bacteria, 18S in eukaryotes)[7][8][9]. While critical for cell viability, uS13 itself is not a classical therapeutic target in humans. However, it and neighboring proteins in the small subunit are essential for antibiotics targeting bacterial translation, with compounds like edeine binding within the initiation complex and inhibiting translation[3]. Eukaryote-specific extensions and interactions of uS13 contribute to the unique architecture and functional complexity of the eukaryotic ribosome[2][4]. No established biomarkers or significant safety concerns are directly attributed to modulation of uS13, though inhibition of ribosomal biogenesis or function can have widespread cytotoxic effects. Caveats: - Direct drug targeting and biomarker roles are primarily relevant to antimicrobial agents against bacteria; uS13 is not selected as a specific drug target in humans[1][3]. - Name mappings differ between species (e.g., S18 in humans versus S13 in bacteria), but “uS13” is a cross-species, standardized nomenclature[1][5].

Other names

40S ribosomal protein S18 (in humans)Ribosomal protein S13RPS18 (gene, humans)Ke-3Ke3D6S218E

Inhibition of protein synthesis (by stabilization/disruption of ribosomal function or mRNA decoding; relevant for antibiotics targeting the bacterial ribosome)[3]; Direct RNA binding, facilitating translation initiation