Catalyzes the synthesis of beta-citryl-L-glutamate and N-acetyl-L-aspartyl-L-glutamate. Beta-citryl-L-glutamate is synthesized more efficiently than N-acetyl-L-aspartyl-L-glutamate. ATP + citrate + L-glutamate = ADP + beta-citrylglutamate + H(+) + phosphate ATP + L-glutamate + N-acetyl-L-aspartate = ADP + H(+) + N-acetyl-L-aspartyl-L-glutamate + phosphate Binds 2 magnesium or manganese ions per subunit. Strongly expressed in brain and testis. Expressed in eyes, thymus, lung, kidney, skeletal muscle, spleen, skin and heart. Expressed in neurons of the neocortex, the gray matter and Purkinje cells. N-acetyl-L-aspartyl-L-glutamate (NAAG) is the most abundant dipeptide present in vertebrate central nervous system (CNS). Beta-citryl-L-glutamate, a structural analog of NAAG, is present in testis and immature brain. Belongs to the RimK family. Extended N-terminus.