Identification of the mammalian queuine transfer RNA ribosyltransferase complex and characterisation of QTRT1 gene-trap mice deficient in queuosine modified transfer RNA

Abstract

Queuine, or Q-base, is a modified form of 7-deazaguanine that is synthesised de novo by eubacteria, but which is obtained from food or the gut flora by eukaryotes. Q-base is enzymatically inserted into the wobble position of transfer RNA molecules tRNA Asp, tRNA Asn, tRNA His and tRNA Tyr through a base-for-base exchange reaction with guanine. The bacterial enzyme that performs this reaction is tRNA guanine transglycosylase (TGT) and is a 42kDa protein in Escherichia coli and Zymomonus mobilis.