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PMID:1898934
| Citation |
Oppermann, FB, Schmidt, B and Steinbüchel, A (1991) Purification and characterization of acetoin:2,6-dichlorophenolindophenol oxidoreductase, dihydrolipoamide dehydrogenase, and dihydrolipoamide acetyltransferase of the Pelobacter carbinolicus acetoin dehydrogenase enzyme system. J. Bacteriol. 173:757-67 |
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| Abstract |
Dihydrolipoamide dehydrogenase (DHLDH), dihydrolipoamide acetyltransferase (DHLTA), and acetoin: 2,6-dichlorophenolindophenol oxidoreductase (Ao:DCPIP OR) were purified from acetoin-grown cells of Pelobacter carbinolicus. DHLDH had a native Mr of 110,000, consisted of two identical subunits of Mr 54,000, and reacted only with NAD(H) as a coenzyme. The N-terminal amino acid sequence included the flavin adenine dinucleotide-binding site and exhibited a high degree of homology to other DHLDHs. DHLTA had a native Mr of greater than 500,000 and consisted of subunits identical in size (Mr 60,000). The enzyme was highly sensitive to proteolytic attack. During limited tryptic digestion, two major fragments of Mr 32,500 and 25,500 were formed. Ao:DCPIP OR consisted of two different subunits of Mr 37,500 and 38,500 and had a native Mr in the range of 143,000 to 177,000. In vitro in the presence of DCPIP, it catalyzed a thiamine pyrophosphate-dependent oxidative-hydrolytic cleavage of acetoin, methylacetoin, and diacetyl. The combination of purified Ao:DCPIP OR, DHLTA, and DHLDH in the presence of thiamine pyrophosphate and the substrate acetoin or methylacetoin resulted in a coenzyme A-dependent reduction of NAD. In the strictly anaerobic acetoin-utilizing bacteria P. carbinolicus, Pelobacter venetianus, Pelobacter acetylenicus, Pelobacter propionicus, Acetobacterium carbinolicum, and Clostridium magnum, the enzymes Ao:DCPIP OR, DHLTA, and DHLDH were induced during growth on acetoin, whereas they were absent or scarcely present in cells grown on a nonacetoinogenic substrate. |
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| Keywords |
Acetoin/metabolism; Acetoin Dehydrogenase/isolation & purification; Acetoin Dehydrogenase/metabolism; Acetyltransferases/isolation & purification; Acetyltransferases/metabolism; Amino Acid Sequence; Bacteria, Anaerobic/enzymology; Chromatography, Ion Exchange; Dihydrolipoamide Dehydrogenase/isolation & purification; Dihydrolipoamide Dehydrogenase/metabolism; Dihydrolipoyllysine-Residue Acetyltransferase; Immunodiffusion; Indicators and Reagents; Kinetics; Molecular Sequence Data; Multienzyme Complexes/isolation & purification; Multienzyme Complexes/metabolism; Oxidoreductases/genetics; Oxidoreductases/isolation & purification; Oxidoreductases/metabolism; Pyruvate Dehydrogenase Complex; Sequence Homology, Nucleic Acid |
| edit table |
Significance
Annotations
| Gene product | Qualifier | GO Term | Evidence Code | with/from | Aspect | Extension | Notes | Status |
|---|---|---|---|---|---|---|---|---|
| GO:0004148: dihydrolipoyl dehydrogenase activity |
ECO:0000021: |
F |
Codes for a subunit(dihydrolipoamide dehydrogenase)that dimerizes to become the E3 subunit dihydrolipoamide dehydrogenase (DHLDH) in the acetoin dehydrogenase complex that catalyzes the conversion of acetoin to acetyl-CoA and acetaldehyde. Table 6 indicates DHLDH is only present in high activity in acetoin utilizing cultures. Fig. 4 illustrates growth of P. carbinolicus in double immunodiffusion tests that gave strong cross-reactions only between organisms capable of utilizing and degrading acetoin |
Missing: with/from | ||||
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References
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