A protein complex that catalyzes the base-exchange of a guanine residue with queuine at the wobble position of the anticodon of tRNAs. The eukaryotic tRNA-guanine transglycosylase exists as a heterodimer of a catalytic subunit (QTRT1 in humans) and an accessory subunit (QTRT2 in humans), whereas the bacterial enzyme is homodimeric.
TGT