In enzymology, an aspartyltransferase () is an enzyme that catalyzes the chemical reaction L-asparagine + hydroxylamine NH3 + L-aspartylhydroxamate Thus, the two substrates of this enzyme are L-asparagine and hydroxylamine, whereas its two products are NH3 and L-aspartylhydroxamate. This enzyme belongs to the family of transferases, specifically the aminoacyltransferases. The systematic name of this enzyme class is L-asparagine:hydroxylamine gamma-aspartyltransferase. Other names in common use include beta-aspartyl transferase, and aspartotransferase. References EC 2.3.2 Enzymes of unknown structure