Catalyzes the oxidative deamination of D-amino acids. Has broad substrate specificity; is mostly active on D-proline, and to a lesser extent, on several other D-amino acids such as D-alanine, D-phenylalanine and D-serine. Mediates electron transport from D-proline to coenzyme Q1 in vitro, and is involved in the electron transport chain from D-proline to the c-type cytochrome in vivo. a D-alpha-amino acid + a quinone + H2O = a 2-oxocarboxylate + a quinol + NH4(+) Belongs to the DadA oxidoreductase family.