Queuine tRNA Ribosyltransferase 1 (QTRT1)

tRNA-guanine transglycosylase (TGT) synthesizes queuosine (Q), which is found in tRNAs that recognize NAU and NAC codons, encoding tyr, asn, asp, and his. Prokaryotic TGT is a single protein of 43 kD. In contrast, mammalian TGT appears to be a heterodimer consisting of a 60-kD subunit (USP14) and a 43-kD catalytic subunit (QTRT1).By database analysis, Deshpande and Katze (2001) identified the QTRT1 gene, which encodes a 403-amino acid protein with a predicted molecular mass of 44 kD. It shares significant identity with several bacterial and eukaryotic homologs.Deshpande and Katze (2001) found that transfection of a QTRT1 construct into a TGT-negative human colon adenocarcinoma line restored the ability of these cells to form Q-containing tRNA.