Description:
<jats:p>Polyphenol oxidases are involved in aurone biosynthesis but the gene responsible for 4‐deoxyaurone formation in <jats:italic>Asteraceae</jats:italic> was so far unknown. Three novel full‐length cDNA sequences were isolated from <jats:italic>Coreopsis grandiflora</jats:italic> with sizes of 1.80 kb (<jats:italic>cgAUS1</jats:italic>) and 1.85 kb (<jats:italic>cgAUS2a</jats:italic>, <jats:italic>2b</jats:italic>), encoding for proteins of 68–69 kDa, respectively. <jats:italic>cgAUS1</jats:italic> is preferably expressed in young petals indicating a specific role in pigment formation. The 58.9 kDa AUS1 holoproenzyme, was recombinantly expressed in <jats:italic>E. coli</jats:italic> and purified to homogeneity. The enzyme shows only diphenolase activity, catalyzing the conversion of chalcones to aurones and was characterized by SDS–PAGE and shot‐gun type nanoUHPLC–ESI‐MS/MS.</jats:p>