This family includes mitochondrial D-glutamate cyclase which converts D-glutamate to 5-oxo-D-proline [1]. This family also includes numerous uncharacterised proteins from bacteria.

1: D-Glutamate is metabolized in the heart mitochondria. Ariyoshi M, Katane M, Hamase K, Miyoshi Y, Nakane M, Hoshino A, Okawa Y, Mita Y, Kaimoto S, Uchihashi M, Fukai K, Ono K, Tateishi S, Hato D, Yamanaka R, Honda S, Fushimura Y, Iwai-Kanai E, Ishihara N, Mita M, Homma H, Matoba S; Sci Rep. 2017;7:43911. PMID:28266638