EC 6.3.5.7

Reaction: ATP + glutamyl-tRNA^Gln + L-glutamine = ADP + phosphate + glutaminyl-tRNA^Gln + L-glutamate

Other name(s): Glu-AdT; Glu-tRNA^Gln amidotransferase; glutamyl-tRNA^Gln amidotransferase; Glu-tRNA^Gln:L-glutamine amido-ligase (ADP-forming)

Systematic name: glutamyl-tRNA^Gln:L-glutamine amido-ligase (ADP-forming)

Comments: In systems lacking discernible glutamine—tRNA ligase (EC 6.1.1.18), glutamyl-tRNA^Gln is formed by a two-enzyme system. In the first step, a nondiscriminating ligase (EC 6.1.1.24, glutamate—tRNA^Gln ligase) mischarges tRNA^Gln with glutamate, forming glutamyl-tRNA^Gln. The glutamyl-tRNA^Gln is not used in protein synthesis until the present enzyme converts it into glutaminyl-tRNA^Gln (glutamyl-tRNA^Glu is not a substrate for this reaction). Ammonia or asparagine can substitute for the preferred substrate glutamine.

Links to other databases: BRENDA, EXPASY, KEGG, CAS registry number: 52232-48-1

References:

1. Horiuchi, K.Y., Harpel, M.R., Shen, L., Luo, Y., Rogers, K.C. and Copeland, R.A. Mechanistic studies of reaction coupling in Glu-tRNA^Gln amidotransferase. Biochemistry 40 (2001) 6450-6457. [PMID: 11371208]

2. Curnow, A.W., Tumbula, D.L., Pelaschier, J.T., Min, B. and Söll, D. Glutamyl-tRNA^Gln amidotransferase in Deinococcus radiodurans may be confined to asparagine biosynthesis. Proc. Natl. Acad. Sci. USA 95 (1998) 12838-12843. [PMID: 9789001]

3. Ibba, M. and Söll, D. Aminoacyl-tRNA synthesis. Annu. Rev. Biochem. 69 (2000) 617-650. [PMID: 10966471]