Prolyl 3-hydroxylase that catalyzes 3-hydroxylation of 'Pro-62' of small ribosomal subunit uS12 (rps23), thereby regulating protein translation termination efficiency. Involved in stress granule formation. 2-oxoglutarate + [ribosomal protein uS12]-L-proline + O2 = [ribosomal protein uS12]-(3S)-3-hydroxy-L-proline + CO2 + succinate Binds 1 Fe(2+) ion per subunit. Monomer. Belongs to the TPA1 family.