Catalyzes the final reaction in the degradation of vitamin B6 from (E)-2-(acetamidomethylene)succinate (E-2AMS) to produce succinic semialdehyde, acetate, ammonia and carbon dioxide. 2-(acetamidomethylene)succinate + H(+) + 2 H2O = acetate + CO2 + NH4(+) + succinate semialdehyde kcat is 307.3 min(-1) for 2-(acetamidomethylene)succinate. Optimum pH is 7.0. Cofactor degradation; B6 vitamer degradation. Homodimer. Belongs to the AB hydrolase superfamily.