Pseudouridylate synthase that catalyzes pseudouridylation of tRNAs and mRNAs (PubMed:15772074, PubMed:24722331). Acts on positions 27/28 in the anticodon stem and also positions 34 and 36 in the anticodon of an intron containing tRNA (PubMed:24722331). Also catalyzes pseudouridylation of mRNAs: mediates pseudouridylation of mRNAs with the consensus sequence 5'-UGUAG-3' (PubMed:31477916, PubMed:35051350). Acts as a regulator of pre-mRNA splicing by mediating pseudouridylation of pre-mRNAs at locations associated with alternatively spliced regions (PubMed:35051350). Pseudouridylation of pre-mRNAs near splice sites directly regulates mRNA splicing and mRNA 3'-end processing (PubMed:35051350). Involved in regulation of nuclear receptor activity through pseudouridylation of SRA1 mRNA (PubMed:24722331). a uridine in tRNA = a pseudouridine in tRNA uridine(38/39/40) in tRNA = pseudouridine(38/39/40) in tRNA a uridine in mRNA = a pseudouridine in mRNA Monomer (PubMed:23707380, PubMed:24722331). Forms a complex with RARG and the SRA1 RNA in the nucleus (By similarity). Widely expressed (PubMed:15108122). High levels of expression found in brain and skeletal muscle (PubMed:15108122). The disease is caused by variants affecting the gene represented in this entry. Belongs to the tRNA pseudouridine synthase TruA family.