Acts as a N-succinylamino acid racemase (NSAR) that catalyzes the racemization of N-succinyl-L-phenylglycine (PubMed:24872444). Also converts 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC) to 2-succinylbenzoate (OSB) (PubMed:24872444). Catalyzes both N-succinylamino acid racemization and OSB synthesis at equivalent rates (PubMed:24872444). However, NSAR activity is probably the protein's biological function, because menaquinone biosynthesis genes are missing in this species (Probable). (1R,6R)-6-hydroxy-2-succinyl-cyclohexa-2,4-diene-1-carboxylate = 2-succinylbenzoate + H2O Binds 1 divalent metal cation per subunit. kcat is 33 sec(-1) with N-succinyl-L-phenylglycine as substrate (PubMed:24872444). kcat is 6.1 sec(-1) with SHCHC as substrate (PubMed:24872444). Homooctamer. Tetramer of dimers. Belongs to the mandelate racemase/muconate lactonizing enzyme family. MenC type 2 subfamily.