Figure 1

Identification of a reporter gene for Ehrlich Pathway activity.

(A) Amino acids (branched-chain amino acids, leucine, isoleucine and valine, aromatic amino acids, phenylalanine, tyrosine and tryptphan, or methionine) are converted in the Ehrlich pathway to fusel alcohol or fusel acids in a three step process. The genes encoding enzymes that catalyze single steps are indicated. Oxidation of aldehydes to fusel acids is done by aldehyde dehydrogenases (e.g. ALD1). Reduction of aldehydes to fusel alcohols is done by alcohol dehydrogenases (e.g. ADH1). Transcriptional regulation by Aro80 and co-factor requirement is indicated. (B) Plasmids carrying the ARO80 overexpression and one of the ARO-promoter-lacZ reporter gene constructs were co-transformed into S. cerevisiae (BY4741). (C) Quantitative β-galactosidase assay with strains bearing the indicated ARO-promoter-lacZ constructs in strains in which ScARO80 was either overexpressed or deleted, or contained the wildtype ARO80.