With S4 and S5 plays an important role in translational accuracy. Located at the interface of the 30S and 50S subunits (By similarity). Part of the 30S ribosomal subunit. Exons 2 and 3 are cis-spliced, while a trans-splicing reaction is required to link exons 1 and 2. Belongs to the universal ribosomal protein uS12 family.