RT Journal Article SR Electronic(1) A1 Dickinson, J. Richard A1 Dawes, Ian W.YR 1992 T1 The catabolism of branched-chain amino acids occurs via 2-oxoacid dehydrogenase in Saccharomyces cerevisiae JF Microbiology, VO 138 IS 10 SP 2029 OP 2033 DO https://doi.org/10.1099/00221287-138-10-2029 PB Microbiology Society, SN 1465-2080, AB Saccharomyces cerevisiae possesses 2-oxoacid dehydrogenase (EC 1.2.4.4) similar to that found in mammalian cells. The activity is readily detected in cells which have been cultured in a minimal medium containing a branched-chain amino acid. Mutants defective in lipoamide dehydrogenase also lack 2-oxoacid dehydrogenase and are thus unable to catabolize branched-chain amino acids: 2-oxoacids accumulate in the cultures of these cells. The 2-oxoacid dehydrogenase activity is distinct from both 2-oxoglutarate dehydrogenase and pyruvate dehydrogenase, because it could not be detected in assay conditions which permitted the measurement of 2-oxoglutarate dehydrogenase and vice versa. In addition, a strain lacking 2-oxoglutarate dehydrogenase (kgd1::URA3) retained 2-oxoacid dehydrogenase as did a mutant specifically lacking pyruvate dehydrogenase (pda1::Tn5ble). In complex media the specific activity of this enzyme is highest in YEP (yeast extract-peptone)-glycerol and lowest in YEP-acetate and YEP-fructose. 2-Oxoacid dehydrogenase could not be detected in cells which had been transferred to sporulation medium. These results suggest that in S. cerevisiae the catabolism of branched-chain amino acids occurs via 2-oxoacid dehydrogenase, not via the ‘Ehrlich Pathway’., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-138-10-2029