Converts 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC) to 2-succinylbenzoate (OSB) (By similarity). Also acts as a N-succinylamino acid racemase (NSAR) that catalyzes the racemization of various N-succinylamino acids, including N-succinyl-alanine and N-succinyl-phenylalanine (Ref.1). Can catalyze the racemization of a broad range of N-acylamino acids, including N-acetyl-methionine, N-acetyl-phenylalanine, N-carbamoyl-methionine, N-formyl-D-methionine, N-formyl-D-norleucine and N-carbamoyl-D-norleucine (Ref.1, PubMed:25875730). May be a bifunctional enzyme involved in menaquinone biosynthesis and in an irreversible pathway for the conversion of D- to L-amino acids, thereby facilitating the survival and/or growth of the organism (By similarity). (1R,6R)-6-hydroxy-2-succinyl-cyclohexa-2,4-diene-1-carboxylate = 2-succinylbenzoate + H2O N(alpha)-acetyl-D-methionine = N(alpha)-acetyl-L-methionine N-acetyl-D-phenylalanine = N-acetyl-L-phenylalanine Shows highest activity in vitro with Co(2+), Mn(2+) and Ni(2+). kcat is 43 sec(-1) with N-succinyl-L-alanine as substrate. kcat is 15 sec(-1) with N-succinyl-D-alanine as substrate. kcat is 5 sec(-1) with N-succinyl-L-phenylalanine as substrate. kcat is 2 sec(-1) with N-succinyl-D-phenylalanine as substrate. kcat is 22 sec(-1) with N-acetyl-L-methionine as substrate. kcat is 20 sec(-1) with N-acetyl-D-methionine as substrate. kcat is 16 sec(-1) with N-acetyl-L-phenylalanine as substrate. kcat is 10 sec(-1) with N-acetyl-D-phenylalanine as substrate. kcat is 2 sec(-1) with N-carbamoyl-L-methionine as substrate. kcat is 2 sec(-1) with N-carbamoyl-D-methionine as substrate. Optimum pH is 8.0. Optimum temperature is 55 degrees Celsius. Quinol/quinone metabolism; 1,4-dihydroxy-2-naphthoate biosynthesis; 1,4-dihydroxy-2-naphthoate from chorismate: step 4/7. Quinol/quinone metabolism; menaquinone biosynthesis. Homotetramer. Belongs to the mandelate racemase/muconate lactonizing enzyme family. MenC type 2 subfamily.