Anti-queuine tRNA-ribosyltransferase 1 antibodies enable researchers to detect and measure the queuine tRNA-ribosyltransferase 1 antigen in biological samples. This target is a reported synonym of the QTRT1 gene, which encodes queuine tRNA-ribosyltransferase catalytic subunit 1. This protein is a known catalytic subunit of the queuine tRNA-ribosyltransferase (TGT) that catalyzes the base-exchange of a guanine (G) residue with queuine (Q) at position 34 (anticodon wobble position) in tRNAs with GU(N) anticodons (tRNA-Asp, -Asn, -His and -Tyr), resulting in the hypermodified nucleoside queuosine (7-(((4,5-cis-dihydroxy-2-cyclopenten-1-yl)amino)methyl)-7-deazaguanosine). The human version of queuine tRNA-ribosyltransferase 1 has a canonical amino acid length of 403 residues and a protein mass of 44 kilodaltons. It is reported to be localized in the membrane, mitochondria, and cytoplasm of cells and notably expressed in many tissues, such as the cerebral cortex, testis, and adrenal gland. Other names for this target antigen include TGT, 43-KD subunit, TGT, catalytic subunit, and guanine insertion enzyme.