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 N-succinyl-D/L-phenylalanine (PubMed:25875730). Can catalyze the racemization of a broad range of N-acylamino acids, including N-acetyl-D-methionine, N-formyl-D/L-methionine, N-formyl-D/L-norleucine, N-formyl-D/L-aminobutyric acid, N-formyl-D/L-norvaline, N-formyl-D/L-homophenylalanine, N-carbamoyl-D-methionine and N-carbamoyl-D-norleucine (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 Shows highest activity in vitro with Co(2+) and Ni(2+). kcat is 74.6 sec(-1) with N-formyl-D-methionine as substrate. kcat is 52.9 sec(-1) with N-formyl-L-methionine as substrate. kcat is 12.3 sec(-1) with N-formyl-D-norleucine as substrate. kcat is 8.0 sec(-1) with N-formyl-L-norleucine as substrate. kcat is 15.2 sec(-1) with N-formyl-D-aminobutyric acid as substrate. kcat is 11.6 sec(-1) with N-formyl-L-aminobutyric acid as substrate. kcat is 11.2 sec(-1) with N-formyl-D-norvaline as substrate. kcat is 19.6 sec(-1) with N-formyl-L-norvaline as substrate. kcat is 88.4 sec(-1) with N-formyl-D-homophenylalanine as substrate. kcat is 85.5 sec(-1) with N-formyl-L-homophenylalanine as substrate. Optimum pH is 8.0-8.5. Optimum temperature is 55-65 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.