Acts as a N-succinylamino acid racemase (NSAR) that catalyzes the racemization of N-succinyl-phenylglycine and N-succinyl-methionine (PubMed:14705949, PubMed:24955846). Can catalyze the racemization of a broad range of N-acylamino acids, including N-acetyl-D/L-methionine, N-propionyl-D/L-methionine, N-butyryl-D/L-methionine and N-chloroacetyl-L-valine (PubMed:7766084, PubMed:10194342, PubMed:14705949, PubMed:23130969). Also converts 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC) to 2-succinylbenzoate (OSB) (PubMed:10194342, PubMed:14705949, PubMed:24955846). Catalyzes both N-succinylamino acid racemization and OSB synthesis at equivalent rates (PubMed:14705949, PubMed:24955846). NSAR is probably the biological function of this enzyme (Probable). N(alpha)-acetyl-D-methionine = N(alpha)-acetyl-L-methionine (1R,6R)-6-hydroxy-2-succinyl-cyclohexa-2,4-diene-1-carboxylate = 2-succinylbenzoate + H2O Binds 1 divalent metal cation per subunit (PubMed:15134446). Enhanced by the addition of divalent metal ions such as Co(2+), Mn(2+) and Fe(2+) (PubMed:7766084). Inhibited by EDTA and sulfhydryl reagents such as p-chloromercuribenzoic acid (PubMed:7766084). Both OSBS and NAAAR activities are inhibited competitively by salicylhydroxamate (PubMed:10194342). kcat is 110 sec(-1) with N-succinyl-R/S-methionine as substrate (PubMed:14705949). kcat is 190 sec(-1) with N-succinyl-R/S-phenylglycine as substrate (PubMed:14705949). kcat is 42 sec(-1) with N-succinyl-L-phenylglycine as substrate (PubMed:24955846). kcat is 20 sec(-1) with N-acetyl-L-methionine as substrate (PubMed:23130969). kcat is 14 sec(-1) with N-acetyl-D-methionine as substrate (PubMed:23130969). kcat is 4.8 sec(-1) with N-acetyl-R-methionine as substrate (PubMed:14705949). kcat is 6.4 sec(-1) with N-acetyl-S-methionine as substrate (PubMed:14705949). kcat is 11.7 sec(-1) with N-acetyl-S-methionine as substrate (PubMed:10194342). kcat is 41 sec(-1) with N-acetyl-D-(4-fluoro)phenylglycine as substrate (PubMed:23130969). kcat is 97 sec(-1) with N-acetyl-allylglycine as substrate (PubMed:23130969). kcat is 120 sec(-1) with SHCHC as substrate (PubMed:10194342, PubMed:14705949). kcat is 46 sec(-1) with SHCHC as substrate (PubMed:24955846). Optimum pH is 7.5. Optimum temperature is 50 degrees Celsius. Stable at 55 degrees Celsius for 30 min. Homooctamer. The active-site cavity can accommodate both the hydrophobic substrate for the OSBS reaction and the substrates for the racemase activity. Accommodation of the components of the N-acyl linkage appears to be the reason that this enzyme is capable of a racemization reaction on these substrates, whereas the orthologous OSBS from E.coli lacks this functionality. Variants with increased racemase activity could be used on an industrial scale for the production of enantiomerically pure alpha-amino acids. Belongs to the mandelate racemase/muconate lactonizing enzyme family. MenC type 2 subfamily.