Abstract
Xanthobacter flavus employs two fructosebisphosphatase (FBPase)-sedoheptulosebisphosphatase (SBPase) enzymes. One of these is constitutively expressed and has a high FBPase-to-SBPase ratio. The alternative enzyme, which is encoded by cbbF, is induced during autotrophic growth. The cbbF gene was expressed in Escherichia coli, and the FBPase was purified to homogeneity. The purified enzyme has a specific FBPase activity of 114 mumol/min/mg of protein, a Michaelis constant for fructosebisphosphate of 3 microM, and a low FBPase-to-SBPase ratio. CbbF was activated by ATP and inhibited by Ca2+.
MeSH terms
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Adenosine Triphosphate / pharmacology
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Calcium / pharmacology
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Enzyme Activation
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Escherichia coli / genetics
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Fructose-Bisphosphatase / drug effects
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Fructose-Bisphosphatase / genetics
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Fructose-Bisphosphatase / isolation & purification
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Fructose-Bisphosphatase / metabolism*
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Fructosediphosphates / metabolism
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Gene Expression Regulation, Bacterial
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Gram-Negative Aerobic Bacteria / enzymology*
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Isoenzymes / drug effects
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Isoenzymes / genetics
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Isoenzymes / isolation & purification
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Isoenzymes / metabolism*
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Phosphoric Monoester Hydrolases / genetics
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Phosphoric Monoester Hydrolases / isolation & purification
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Phosphoric Monoester Hydrolases / metabolism*
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
Substances
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Fructosediphosphates
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Isoenzymes
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Recombinant Proteins
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Adenosine Triphosphate
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Fructose-Bisphosphatase
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Phosphoric Monoester Hydrolases
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sedoheptulose-bisphosphatase
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Calcium