FAD-dependent oxidoreductase; part of the gene cluster that mediates the biosynthesis of the antibiotic 2,4-dihydroxy-3-methyl-6-(2-oxopropyl)benzaldehyde (DHMBA) and its derivatives (PubMed:22510154, PubMed:23001671). The direct non-reducing polyketide synthase dbaI product is 2,4-dihydroxy-3-methyl-6-(2-oxopropyl)benzaldehyde (DHMBA), produced by condensation of one acetyl-CoA starter unit with 4 malonyl-CoA units and one methylation step (PubMed:22510154). The FAD-dependent monooxygenase dbaH is responsible for the synthesis of yellow pigments derived from the oxidation of DHMBA (PubMed:23001671). The roles of dbaB, C, E and F have still to be determined (Probable). Secondary metabolite biosynthesis. Deletion of the conserved eukaryotic csnE deneddylase subunit of the COP9 signalosome leading to defect in protein degradation results in the activation of the silenced dba gene cluster (PubMed:23001671). Expression is positively regulated by the dba cluster specific transcription factors dbaA and dbaG (PubMed:23001671). Expression is also controlled by the transcription factor flbB (PubMed:25701285). Reduces the amounts of DHMDA produced. Belongs to the beta-cyclopiazonate dehydrogenase family.