Catalyzes the conversion of acetaldehyde or propanal to acetyl-CoA or propanoyl-CoA, respectively, using NAD(+) and coenzyme A. The aldehyde substrates can be directly channeled from the aldolase TTHB246 to the dehydrogenase TTHB247. Is the final enzyme in the meta-cleavage pathway for the degradation of aromatic compounds. acetaldehyde + CoA + NAD(+) = acetyl-CoA + H(+) + NADH CoA + NAD(+) + propanal = H(+) + NADH + propanoyl-CoA The catalytic efficiency is similar when using acetaldehyde or propanaldehyde as substrate. Has a half-life of only 1.6 hours at 50 degrees Celsius. When TTHB247 is in complex with TTHB246, its half-life is increased by approximately 4 hours. Monomer. Can also form a heterotetramer composed of two aldolase (TTHB246) and two dehydrogenase (TTHB247) subunits. Upon complex formation, the aldolase shows a 5-fold increase in substrate affinity, while the dehydrogenase shows a 3-fold decrease; the kcat values of each enzyme are reduced by 2-fold when they are in a complex. Belongs to the acetaldehyde dehydrogenase family.