In enzymology, a diaminopimelate epimerase (EC 5.1.1.7) is an enzyme that catalyzes the chemical reaction LL-2,6-diaminoheptanedioate meso-diaminoheptanedioate Hence, this enzyme has one substrate, LL-2,6-diaminoheptanedioate, and one product, . This enzyme belongs to the family of isomerases, specifically those racemases and epimerases acting on amino acids and derivatives. The systematic name of this enzyme class is LL-2,6-diaminoheptanedioate 2-epimerase. This enzyme participates in lysine biosynthesis.