Biomaterial Database

The catabolism of branched-chain amino acids occurs via 2-oxoacid dehydrogenase in Saccharomyces cerevisiae. 1992

J R Dickinson, and I W Dawes

School of Biochemistry and Molecular Genetics, University of New South Wales, Kensington, Australia.

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'.

UI	MeSH Term	Description	Entries
D007651	Keto Acids	Carboxylic acids that contain a KETONE group.	Oxo Acids,Oxoacids,Acids, Keto,Acids, Oxo
D007655	Ketoglutarate Dehydrogenase Complex		2-Keto-4-Hydroxyglutarate Dehydrogenase,2-Oxoglutarate Dehydrogenase,2-Oxoglutarate Dehydrogenase Complex,Oxoglutarate Dehydrogenase,alpha-Ketoglutarate Dehydrogenase,alpha-Ketoglutarate Dehydrogenase Complex,2 Keto 4 Hydroxyglutarate Dehydrogenase,2 Oxoglutarate Dehydrogenase,2 Oxoglutarate Dehydrogenase Complex,Complex, 2-Oxoglutarate Dehydrogenase,Complex, Ketoglutarate Dehydrogenase,Complex, alpha-Ketoglutarate Dehydrogenase,Dehydrogenase Complex, 2-Oxoglutarate,Dehydrogenase Complex, Ketoglutarate,Dehydrogenase Complex, alpha-Ketoglutarate,Dehydrogenase, 2-Keto-4-Hydroxyglutarate,Dehydrogenase, 2-Oxoglutarate,Dehydrogenase, Oxoglutarate,Dehydrogenase, alpha-Ketoglutarate,alpha Ketoglutarate Dehydrogenase,alpha Ketoglutarate Dehydrogenase Complex
D007658	Ketone Oxidoreductases	Oxidoreductases that are specific for KETONES.	Oxidoreductases, Ketone
D008058	Dihydrolipoamide Dehydrogenase	A flavoprotein containing oxidoreductase that catalyzes the reduction of lipoamide by NADH to yield dihydrolipoamide and NAD+. The enzyme is a component of several MULTIENZYME COMPLEXES.	Lipoamide Dehydrogenase,NAD Diaphorase,NADH Diaphorase,Diaphorase (Lipoamide Dehydrogenase),Dihydrolipoyl Dehydrogenase,Glycine Decarboxylase Complex L-Protein,L-Protein, Glycine Decarboxylase Complex,Lipoamide Dehydrogenase, Valine,Lipoic Acid Dehydrogenase,Lipoyl Dehydrogenase,Valine Lipoamide Dehydrogenase,Dehydrogenase, Dihydrolipoamide,Dehydrogenase, Dihydrolipoyl,Dehydrogenase, Lipoamide,Dehydrogenase, Lipoic Acid,Dehydrogenase, Lipoyl,Dehydrogenase, Valine Lipoamide,Diaphorase, NAD,Diaphorase, NADH,Glycine Decarboxylase Complex L Protein
D009097	Multienzyme Complexes	Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.	Complexes, Multienzyme
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D011768	Pyruvate Dehydrogenase Complex	A multienzyme complex responsible for the formation of ACETYL COENZYME A from pyruvate. The enzyme components are PYRUVATE DEHYDROGENASE (LIPOAMIDE); dihydrolipoamide acetyltransferase; and LIPOAMIDE DEHYDROGENASE. Pyruvate dehydrogenase complex is subject to three types of control: inhibited by acetyl-CoA and NADH; influenced by the energy state of the cell; and inhibited when a specific serine residue in the pyruvate decarboxylase is phosphorylated by ATP. PYRUVATE DEHYDROGENASE (LIPOAMIDE)-PHOSPHATASE catalyzes reactivation of the complex. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)	Complex, Pyruvate Dehydrogenase,Dehydrogenase Complex, Pyruvate
D003470	Culture Media	Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.	Media, Culture
D000597	Amino Acids, Branched-Chain	Amino acids which have a branched carbon chain.	Branched-Chain Amino Acid,Amino Acids, Branched Chain,Acid, Branched-Chain Amino,Acids, Branched-Chain Amino,Amino Acid, Branched-Chain,Branched Chain Amino Acid,Branched-Chain Amino Acids
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker