The promoter activity of isovaleryl-CoA dehydrogenase-encoding gene (ivdA) from Aspergillus oryzae is strictly repressed by glutamic acid.

We cloned the isovaleryl-CoA dehydrogenase (IVD)-encoding gene from Aspergillus oryzae. The promoter of ivdA was subjected to beta-glucuronidase (GUS) reporter assays in which certain amino acids were used as a major carbon source. L-leucine most strongly induced GUS-activity, while in the case of L-glutamate, significantly low activity was found, indicating that ivdA transcription was strongly repressed by glutamic acid.