Minor enzyme contributing to the isomerization of uridine to pseudouridine (pseudouridylation) of specific mitochondrial mRNAs (mt- mRNAs) such as COXI and COXIII mt-mRNAs (PubMed:27974379, PubMed:31477916). As a component of a functional protein-RNA module, consisting of RCC1L, NGRN, RPUSD3, RPUSD4, TRUB2, FASTKD2 and 16S mitochondrial ribosomal RNA (16S mt-rRNA), controls 16S mt-rRNA abundance and is required for intra-mitochondrial translation (PubMed:27667664). Also catalyzes pseudouridylation of some tRNAs, including synthesis of pseudouridine(55) from uracil-55, in the psi GC loop of a subset of tRNAs (PubMed:33023933). {ECO:0000269|PubMed:27667664, ECO:0000269|PubMed:27974379, ECO:0000269|PubMed:31477916, ECO:0000269|PubMed:33023933}. This is the function of Ensembl gene identifier ENSG00000167112 (TRUB2, TruB pseudouridine synthase family member 2).