title: Isolation of a negative control mutant of the nitrogen assimilation control protein, NAC, in Klebsiella aerogenes.
abstract: A negative control mutant of the nitrogen assimilation control protein, NAC, has been isolated. Mutants with the leucine at position 111 changed to a nonhydrophobic residue activate transcription from hut and ure promoters, but fail to repress gdhA expression. This failure does not result from failure to bind to either of the two sites required for gdhA repression, but the binding at those sites is altered in the mutant. It appears that the NAC negative control mutants fail to form the complex structures (probably tetramers) formed by wild-type NAC at the gdhA promoter.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor 48109-1048, USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Janes
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Rosario
authors.forename: Robert A
authors.initials: RA
authors.lastname: Bender
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D021902:Enterobacter aerogenes / Q000235:genetics* / Q000378:metabolism; D004794:Enzyme Repression / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D018698:Glutamic Acid / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011401:Promoter Regions, Genetic; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D014508:Urea / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C072712:NAC protein, bacteria; D015534:Trans-Activators; D014157:Transcription Factors; D018698:Glutamic Acid; D006639:Histidine; D014508:Urea