Abstract
gamma-Glutamyl-gamma-aminobutyrate hydrolase (PuuD) was purified and the properties of the enzyme were characterized. The active center of PuuD was identified as Cys-114 by site-directed mutagenesis. The expression of PuuD was induced by putrescine and O2 (substrates of the Puu pathway), while the addition of succinate or NH4Cl (products of the Puu pathway) to the medium reduced the expression of PuuD. The findings that the puuD-deficient strain accumulated gamma-glutamyl-gamma-aminobutyrate (gamma-Glu-GABA) and could not grow on putrescine as a sole nitrogen source indicate that PuuD is physiologically important as a gamma-Glu-GABA hydrolase.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Aldehyde Oxidoreductases / genetics
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Aldehyde Oxidoreductases / isolation & purification*
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Aldehyde Oxidoreductases / metabolism
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Ammonium Chloride / pharmacology
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Binding Sites / genetics
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Dipeptides / metabolism
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Escherichia coli K12 / enzymology*
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Escherichia coli K12 / genetics
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Escherichia coli K12 / growth & development
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Escherichia coli K12 / metabolism
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Gene Expression Regulation, Bacterial
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Mutagenesis, Site-Directed
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Nitrogen / metabolism
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Oxygen / pharmacology
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Putrescine / metabolism*
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Putrescine / pharmacology
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Succinic Acid / pharmacology
Substances
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Dipeptides
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Ammonium Chloride
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gamma glutamyl GABA
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Succinic Acid
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Aldehyde Oxidoreductases
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aminobutyraldehyde dehydrogenase
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Nitrogen
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Oxygen
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Putrescine