In enzymology, a tryptophanâÂÂtRNA ligase () is an enzyme that catalyzes the chemical reaction
The 3 substrates of this enzyme are ATP, -tryptophan, and tRNA, whereas its 3 products are AMP, diphosphate, and -tryptophyl-tRNA.
This enzyme belongs to the family of ligases, to be specific those forming carbonâÂÂoxygen bonds in aminoacyl-tRNA and related compounds. The systematic name of this enzyme class is -tryptophan:tRNA ligase (AMP-forming). Other names in common use include tryptophanyl-tRNA synthetase, -tryptophan-tRNA ligase (AMP-forming), tryptophanyl-transfer ribonucleate synthetase, tryptophanyl-transfer ribonucleic acid synthetase, tryptophanyl-transfer RNA synthetase, tryptophanyl ribonucleic synthetase, tryptophanyl-transfer ribonucleic synthetase, tryptophanyl-tRNA synthase, tryptophan translase, and TrpRS. This enzyme participates in tryptophan metabolism and aminoacyl-tRNA biosynthesis.
As of late 2007, 21 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , , , , , , , , , , , , and .