title: Mutants of Klebsiella aerogenes lacking glutamate dehydrogenase.
abstract: A mutant of Klebsiella aerogenes lacking glutamate synthase activity (asm-200) is blocked in only one pathway of glutamate synthesis and can still use glutamate dehydrogenase to produce glutamate when ammonia in sufficient concentration, i.e., higher than 1 mM, is provided in the medium. However, a mutant that has neither glutamate synthase nor glutamate dehydrogenase activities (asm-200, gdhD1) requires glutamate. Transductants obtained by phage grown on wild-type cells of this double mutant, selected on medium containing less than 1 mM ammonia, regain glutamate synthase but not glutamate dehydrogenase. Surprisingly, these gdhD1 transductants grow as well in a variety of media as does a strain with glutamate dehydrogenase activity. Furthermore, transductions with these and other mutants indicate that the genes encoding glutamate synthase, glutamate dehydrogenase, glutamine synthetase, and citrate synthase are not closely linked.
mesh_terms: D000476:Alkanesulfonates; D000641:Ammonia / Q000378:metabolism; D002474:Cell-Free System; D002950:Citrate (si)-Synthase / Q000378:metabolism; D002951:Citrates / Q000378:metabolism; D003470:Culture Media; D005796:Genes; D005947:Glucose / Q000378:metabolism; D005969:Glutamate Dehydrogenase / Q000096:biosynthesis* / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D007709:Klebsiella / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D009153:Mutagens; D009154:Mutation; D000637:Transaminases / Q000378:metabolism; D014161:Transduction, Genetic
chemical_list: D000476:Alkanesulfonates; D002951:Citrates; D003470:Culture Media; D005971:Glutamates; D009153:Mutagens; D005973:Glutamine; D006639:Histidine; D000641:Ammonia; D005969:Glutamate Dehydrogenase; D002950:Citrate (si)-Synthase; D000637:Transaminases; D005974:Glutamate-Ammonia Ligase; D005947:Glucose