The function of TSLIG3B (tRNA splicing ligase complex subunit 3B, Ensembl gene identifier ENSG00000171262) is as follows. Accessory subunit of the tRNA-splicing ligase complex that acts by directly joining spliced tRNA halves to mature-sized tRNAs by incorporating the precursor-derived splice junction phosphate into the mature tRNA as a canonical 3',5'-phosphodiester. May act as an RNA ligase with broad substrate specificity and may function toward other RNAs (PubMed:21311021, PubMed:24870230). Could regulate the expression of PRMT1, a protein arginine N-methyltransferase (PubMed:28040436). {ECO:0000269|PubMed:21311021, ECO:0000269|PubMed:24870230, ECO:0000269|PubMed:28040436}.