Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In enzymology, a valine-tRNA ligase (EC 6.1.1.9) is an enzyme that catalyzes the chemical reaction. ATP + L-valine + tRNAVal rightleftharpoons AMP + diphosphate + L-valyl-tRNAVal. The 3 substrates of this enzyme are ATP, L-valine, and tRNA(Val), whereas its 3 products are AMP, diphosphate, and L-valyl-tRNA(Val). This enzyme belongs to the family of ligases, specifically those forming carbon-oxygen bonds in aminoacyl-tRNA and related compounds. The systematic name of this enzyme class is L-valine:tRNAVal ligase (AMP-forming). Other names in common use include valyl-tRNA synthetase, valyl-transfer ribonucleate synthetase, valyl-transfer RNA synthetase, valyl-transfer ribonucleic acid synthetase, valine transfer ribonucleate ligase, and valine translase. This enzyme participates in valine, leucine and isoleucine biosynthesis and aminoacyl-trna biosynthesis.