Ribosomal protein uS17 is one of the three primary assembly proteins (S4, S17 and S20) that stabilize the entire 5' rRNA domain and increase the global stability of the rRNA structure. uS17 is highly conserved in all three major phylogenetic divisions. In eukaryotes, the S17 ortholog of the cytoplasmic ribosome is called S11 as are those of the mitochondrial and chloroplast ribosomes. uS17 plays a critical role in both subunit assembly and translational fidelity.