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Fig. 1 Glycosyl queuosines in mammalian cytoplasmic tRNAs (A and B) Secondary structures of human tRNATyr (A) and tRNAAsp (B) harboring galQ and manQ at position 34, respectively. The Q side chain is colored blue, and galactose and mannose moieties are colored red and green, respectively. (C) Biogenesis of Q-tRNAs and glycosyl-Q-tRNAs in eukaryotes. tRNAs for Tyr, Asp, His, and Asn are modified by the QTRT1/QTRT2 heterodimer to form Q34. Q34 of tRNATyr is further galactosylated to form galQ34 by QTGAL in the presence of UDP-galactose (UDP-gal), while Q34 of tRNAAsp is further mannnosylated to form manQ34 by QTMAN in the presence of GDP-mannose (GDP-man). (D and F) Detection of QTGAL (D) or QTMAN (F) activity in rat liver lysates. Extracted-ion chromatograms (XICs) of Q-containing fragments (upper) and galQ-(D) or manQ-(F) containing fragments (lower) of human tRNATyr (D) or E. coli tRNAAsp (F) digested by RNase T1 in the presence of crude lysate with or without UDP-gal (D) or GDP-man (F). (E and G) CID spectrum of galQ- (E) or manQ- (G) containing fragment. c and y series product ions are assigned. >p, 2′, 3′-cyclic phosphate. m2A, 2-methyladenosine. See also Figure S1, Figure S10, Figure S11, Figure S12.
Reprinted from Cell, 186(25), Zhao, X., Ma, D., Ishiguro, K., Saito, H., Akichika, S., Matsuzawa, I., Mito, M., Irie, T., Ishibashi, K., Wakabayashi, K., Sakaguchi, Y., Yokoyama, T., Mishima, Y., Shirouzu, M., Iwasaki, S., Suzuki, T., Suzuki, T., Glycosylated queuosines in tRNAs optimize translational rate and post-embryonic growth, 5517-5535.e24, Copyright (2023) with permission from Elsevier. Full text @ Cell