EC 2.4.99.17     
Accepted name: S-adenosylmethionine:tRNA ribosyltransferase-isomerase
Reaction: S-adenosyl-L-methionine + 7-aminomethyl-7-carbaguanosine34 in tRNA = L-methionine + adenine + epoxyqueuosine34 in tRNA
Glossary: 7-aminomethyl-7-carbaguanine = preQ1 = 7-aminomethyl-7-deazaguanine
epoxyqueosine = oQ
Other name(s): QueA enzyme; queuosine biosynthesis protein QueA
Systematic name: S-adenosyl-L-methionine:7-aminomethyl-7-deazaguanosine ribosyltransferase (ribosyl isomerizing; L-methionine, adenine releasing)
Comments: The reaction is a combined transfer and isomerization of the ribose moiety of S-adenosyl-L-methionine to the modified guanosine base in the wobble position in tRNAs specific for Tyr, His, Asp or Asn. It is part of the queuosine biosynthesis pathway.
References:
1.  Slany, R.K., Bosl, M., Crain, P.F. and Kersten, H. A new function of S-adenosylmethionine: the ribosyl moiety of AdoMet is the precursor of the cyclopentenediol moiety of the tRNA wobble base queuine. Biochemistry 32 (1993) 7811–7817. [PMID: 8347586]
2.  Slany, R.K., Bosl, M. and Kersten, H. Transfer and isomerization of the ribose moiety of AdoMet during the biosynthesis of queuosine tRNAs, a new unique reaction catalyzed by the QueA protein from Escherichia coli. Biochimie 76 (1994) 389–393. [PMID: 7849103]
3.  Kinzie, S.D., Thern, B. and Iwata-Reuyl, D. Mechanistic studies of the tRNA-modifying enzyme QueA: a chemical imperative for the use of AdoMet as a "ribosyl" donor. Org. Lett. 2 (2000) 1307–1310. [PMID: 10810734]
4.  Van Lanen, S.G. and Iwata-Reuyl, D. Kinetic mechanism of the tRNA-modifying enzyme S-adenosylmethionine:tRNA ribosyltransferase-isomerase (QueA). Biochemistry 42 (2003) 5312–5320. [PMID: 12731872]
5.  Mathews, I., Schwarzenbacher, R., McMullan, D., Abdubek, P., Ambing, E., Axelrod, H., Biorac, T., Canaves, J.M., Chiu, H.J., Deacon, A.M., DiDonato, M., Elsliger, M.A., Godzik, A., Grittini, C., Grzechnik, S.K., Hale, J., Hampton, E., Han, G.W., Haugen, J., Hornsby, M., Jaroszewski, L., Klock, H.E., Koesema, E., Kreusch, A., Kuhn, P., Lesley, S.A., Levin, I., Miller, M.D., Moy, K., Nigoghossian, E., Ouyang, J., Paulsen, J., Quijano, K., Reyes, R., Spraggon, G., Stevens, R.C., van den Bedem, H., Velasquez, J., Vincent, J., White, A., Wolf, G., Xu, Q., Hodgson, K.O., Wooley, J. and Wilson, I.A. Crystal structure of S-adenosylmethionine:tRNA ribosyltransferase-isomerase (QueA) from Thermotoga maritima at 2.0 Å resolution reveals a new fold. Proteins 59 (2005) 869–874. [PMID: 15822125]
6.  Grimm, C., Ficner, R., Sgraja, T., Haebel, P., Klebe, G. and Reuter, K. Crystal structure of Bacillus subtilis S-adenosylmethionine:tRNA ribosyltransferase-isomerase. Biochem. Biophys. Res. Commun. 351 (2006) 695–701. [PMID: 17083917]
[EC 2.4.99.17 created 2012]