A CoA-acylating aldehyde dehydrogenase required for optimal 1,2-propanediol (1,2-PD) degradation. Optimizes growth in the bacterial microcompartment (BMC) dedicated to 1,2-PD degradation by minimizing propionaldehyde toxicity. NAD(+) and NADH are regenerated internally within the Pdu BMC by the PduP and PduQ enzymes, which reduce NAD(+) and oxidize NADH respectively, although there must also be cofactor transport across the BMC (By similarity). Directly targeted to the BMC (PubMed:24933391). Expression of a cosmid containing the full 21-gene pdu operon in E.coli allows E.coli to grow on 1,2-propanediol (1,2-PD) with the appearance of bacterial microcompartments (BMC) in its cytoplasm. The 1,2-PD-specific bacterial microcompartment (BMC) concentrates low levels of 1,2-PD catabolic enzymes, concentrates volatile reaction intermediates thus enhancing pathway flux and keeps the level of toxic, mutagenic propionaldehyde low. CoA + NAD(+) + propanal = H(+) + NADH + propanoyl-CoA Polyol metabolism; 1,2-propanediol degradation. Interacts with PduK, probably with its BMC-containing N-terminus (PubMed:24933391). Interacts with shell proteins PduA and PduJ, interacts with PduQ (By similarity). The N-terminal 18 residues form an alpha-helix which targets this enzyme and foreign proteins (tested with mCherry, pea ascorbate peroxidase and pyruvate decarboxylase) to the BMC. Ethanogenic BMCs can be made in E.coli by targeting pyruvate decarboxylase (pdc) and alcohol dehydrogenase (adh) to them. PduP(1-18)-Pdc and PduD(1-18)-Adh strains targeted to the BMC (PduA, PduB, PduJ, PduK, PduN, PduU) make significantly more ethanol than strains where Pdc and Adh are not targeted to the BMC. Belongs to the EutE/PduP family.