This superfamily entry represents the ribosomal protein S16 found in the small subunit (30S) of the ribosome, found in bacteria, plant chloroplasts and mitochondria. The gene for ribosomal protein S16 (rps16) is encoded in the chloroplast genome of most higher plants but not in Medicago truncatula and Populus alba. These 2 species have compensated for loss of the rps16 from the chloroplast genome by having a mitochondrial rps16 that can target the chloroplasts as well as mitochondria. RPS16 is essential for viability and plays an important role in the assembly of the 30S subunit.

Small subunit assembly mapping suggests that S16 binding is facilitated by prior assembly of S4, S20 and rRNA. S16 binding, in turn, facilitates binding of S5 and S12. S16 specifically interacts with rRNA, in particular with rRNA helix 21, due to its location in the narrow crevice of the 30S subunit, in close proximity to S4 and S20 proteins. In E. coli, extra-ribosomal DNAse functions have also been suggested PMID:9288907. The structured part of S16 consists of four antiparallel beta-strands, an alpha-helix, a parallel beta-strand and a second alpha-helix.

PFAM:PF00886, INTERPRO:IPR023803,PMID:10997906,PMID:18453549