Tags: Enzyme.
In enzymology a histidine-tRNA ligase (EC 6.1.1.21) is an enzyme that catalyzes the chemical reactionATP + L-histidine + tRNAHis AMP + diphosphate + L-histidyl-tRNAHisThe 3 substrates of this enzyme are ATP L-histidine and tRNA(His) whereas its 3 products are AMP diphosphate and L-histidyl-tRNA(His).This enzyme belongs to the family of ligases to be specific those forming carbon-oxygen bonds in aminoacyl-tRNA and related compounds.