In enzymology, an arginyltransferase is an enzyme that catalyzes the chemical reaction L-arginyl-tRNA + protein ⇌ {\displaystyle \rightleftharpoons } tRNA + L-arginyl-proteinThus, the two substrates of this enzyme are L-arginyl-tRNA and protein, whereas its two products are tRNA and L-arginyl-protein. Wikipedia