In enzymology, a leucine—tRNA ligase (EC 6.1.1.4) is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are ATP, L-leucine, and tRNA(Leu), whereas its 3 products are AMP, diphosphate, and L-leucyl-tRNA(Leu).
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-leucine:tRNALeu ligase (AMP-forming).
This enzyme participates in valine, leucine and isoleucine biosynthesis and aminoacyl-trna biosynthesis.
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1WKB, 1WZ2, 2AJG, 2AJH, and 2AJI.