Catalyzes the pyridoxal-dependent decarboxylation of aspartate to produce beta-alanine. Has weak activity with glutamate. H(+) + L-aspartate = beta-alanine + CO2 kcat is 0.075 sec(-1) at 28 degrees Celsius. kcat is 0.008 sec(-1) at 37 degrees Celsius. Cofactor biosynthesis; (R)-pantothenate biosynthesis; beta-alanine from L-aspartate: step 1/1. Deletion mutant cannot grow in minimal medium. Belongs to the group II decarboxylase family.