Abstract
A total of 41 mutants lacking NADP L-glutamate dehydrogenase (NADP-GDH) activity have been studied. All the mutations were located at the gdhA locus within 0-1% recombination of gdhAI. Two mutants, gdhAI and gdhA2, out of five examined, produced cross-reacting material which neutralized NADP-GDH anti-serum. The mutant gdhA9 has altered Km values for all five substrates: ammonium, alpha-ketoglutarate, l-glutamate, NADPH and NADP. The mutant gdhA20 had temperature-sensitive growth, abnormal ammonium-regulation characteristics and thermolabile NADP-GDH activity. These results show that gdhA is the structural gene for NADP-GDH.
MeSH terms
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Aldehyde Oxidoreductases / metabolism
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Ammonia / metabolism
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Aspergillus nidulans / enzymology*
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Aspergillus nidulans / metabolism
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Cell-Free System
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Chromosome Mapping
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Crosses, Genetic
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Electrophoresis, Starch Gel
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Genes*
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Genetic Complementation Test
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Glutamate Dehydrogenase / biosynthesis*
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Glutamate Dehydrogenase / metabolism
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Glutamates / metabolism
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Ketoglutaric Acids / metabolism
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Mutation
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NADP / metabolism
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Nitrate Reductases / metabolism
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Nitrates / metabolism
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Nitrosoguanidines
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Recombination, Genetic
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Stereoisomerism
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Thiourea / metabolism
Substances
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Glutamates
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Ketoglutaric Acids
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Nitrates
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Nitrosoguanidines
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NADP
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Ammonia
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Aldehyde Oxidoreductases
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Glutamate Dehydrogenase
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Nitrate Reductases
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Thiourea