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ENZYME entry: EC

Accepted Name
glutamate--tRNA(Gln) ligase
Alternative Name(s)
nondiscriminating glutamyl-tRNA synthetase
Reaction catalysed
ATP + L-glutamate + tRNA(Glx) = AMP + diphosphate + L-glutamyl-tRNA(Glx)
  • When this enzyme acts on tRNA(Glu), it catalyzes the same reaction as EC
  • It has, however, diminished discrimination, so that it can also form glutamate-tRNA(Gln).
  • This relaxation of specificity has been found to result from the absence of a loop in the tRNA that specifically recognizes the third position of the anticodon.
  • This accounts for the ability of this enzyme in, for example, Bacillus subtilis, to recognize both tRNA1(Gln) (UUG anticodon) and tRNA(Glu) (UUC anticodon) but not tRNA2(Gln) (CUG anticodon).
  • The ability of this enzyme to recognize both tRNA(Glu) and one of the tRNA(Gln) isoacceptors derives from their sharing a major identity element, a hypermodified derivative of U34 (5-methylaminomethyl-2- thiouridine).
  • The glutamyl-tRNA(Gln) is not used in protein synthesis until it is converted by EC into glutaminyl-tRNA(Gln).
PRIAM enzyme-specific profiles6.1.1.24
KEGG Ligand Database for Enzyme Nomenclature6.1.1.24
IUBMB Enzyme Nomenclature6.1.1.24
MEDLINEFind literature relating to
Rhea expert-curated reactions6.1.1.24

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