With S4 and S5 plays an important role in translational accuracy. Interacts with and stabilizes bases of the 16S rRNA that are involved in tRNA selection in the A site and with the mRNA backbone. Located at the interface of the 30S and 50S subunits, it traverses the body of the 30S subunit contacting proteins on the other side and probably holding the rRNA structure together. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit. Part of the 30S ribosomal subunit. Contacts proteins S8 and S17. May interact with IF1 in the 30S initiation complex. Belongs to the universal ribosomal protein uS12 family. Because the enzyme that would modify Asp-102 to 3-methylthioaspartic acid has not been found in the proteome of this organism, that modification is not predicted.