In enzymology, a tryptophan–tRNA ligase (EC 6.1.1.2) is an enzyme that catalyzes the chemical reaction
ATP + L-tryptophan + tRNATrp ⇌ {\displaystyle \rightleftharpoons } AMP + diphosphate + L-tryptophyl-tRNATrp The 3 substrates of this enzyme are ATP, L-tryptophan, and tRNATrp, whereas its 3 products are AMP, diphosphate, and L-tryptophyl-tRNATrp. This enzyme belongs to the family of ligases, to be specific those forming carbon–oxygen bonds in aminoacyl-tRNA and related compounds. The systematic name of this enzyme class is L-tryptophan:tRNATrp ligase (AMP-forming). Other names in common use include tryptophanyl-tRNA synthetase, L-tryptophan-tRNATrp 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.
Structural studies As of late 2007, 21 structures have been solved for this class of enzymes, with PDB accession codes PDB: 1D2R, PDB: 1I6K, PDB: 1I6L, PDB: 1I6M, PDB: 1M83, PDB: 1MAU, PDB: 1MAW, PDB: 1MB2, PDB: 1O5T, PDB: 1R6T, PDB: 1R6U, PDB: 1ULH, PDB: 1YIA, PDB: 1YID, PDB: 2A4M, PDB: 2AKE, PDB: 2AZX, PDB: 2DR2, PDB: 2G36, PDB: 2IP1, and PDB: 2OV4.
References
DAVIE EW, KONINGSBERGER VV, LIPMANN F (1956). "The isolation of a tryptophan-activating enzyme from pancreas". Arch. Biochem. Biophys. 65 (1): 21–38. doi:10.1016/0003-9861(56)90173-4. PMID 13373404. Preddie EC (1969). "Tryptophanyl transfer ribonucleic acid synthetase from bovine pancreas. II. The chemically different subunits". J. Biol. Chem. 244 (14): 3958–68. doi:10.1016/S0021-9258(17)36442-6. PMID 5805407. Wong KK, Meister A, Moldave K (1959). "Enzymic formation of ribonucleic acid-amino acid from synthetic aminoacyladenylate and ribonucleic acid". Biochim. Biophys. Acta. 36 (2): 531–533. doi:10.1016/0006-3002(59)90196-9. PMID 13845797.
