Figure 1.
The QTRT enzyme recognizes 7-deazaguanine derivatives as substrates. (A) The QTRT catalyzed ribosyltransferase reaction removes a nuclear encoded guanine base from position 34 of G34U35N36 tRNA and inserts the queuine micronutrient in its place, in an energy-independent, base-for-base exchange reaction. (B) Structure of adenine and simple deazaguanine derivatives used in tRNA incorporation assays. (C) Nucleobases (50 μM) were assessed for their ability to displace [3H] Guanine from pre-labeled tRNATyr (10 μM) catalyzed by the QTRT enzyme (100 nM). Data are mean ± SD (n = 3). Representative of two independent experiments.