title: GcvR interacts with GcvA to inhibit activation of the Escherichia coli glycine cleavage operon.
abstract: The Escherichia coli glycine cleavage enzyme system, encoded by the gcvTHP operon, catalyses the oxidative cleavage of glycine to CO(2), NH(3) and a one-carbon methylene group. Transcription of the gcv operon is positively regulated by GcvA and negatively regulated by GcvA and GcvR. Using a LexA-based system for analysing protein heterodimerization, it is shown that GcvR interacts directly with GcvA in vivo to repress gcvTHP expression. Several mutations in either gcvA or gcvR that result in a loss of gcv repression also result in a loss of GcvA/GcvR heterodimerization. Finally, it is shown that the C-terminal half of GcvA is involved in its interaction with GcvR, whilst the entire GcvR protein appears to be necessary for heterodimerization.
authors.affiliation: Department of Microbiology, The University of Iowa, Iowa City, IA 52242, USA1.
authors.forename: Angela C
authors.initials: AC
authors.lastname: Ghrist
authors.affiliation: Department of Microbiology, The University of Iowa, Iowa City, IA 52242, USA1.
authors.forename: Gary
authors.initials: G
authors.lastname: Heil
authors.affiliation: Department of Microbiology, The University of Iowa, Iowa City, IA 52242, USA1.
authors.forename: George V
authors.initials: GV
authors.lastname: Stauffer
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D009097:Multienzyme Complexes / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D009876:Operon; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014166:Transferases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C095454:GcvA protein, E coli; C095455:GcvR protein, E coli; D009097:Multienzyme Complexes; D012097:Repressor Proteins; D014157:Transcription Factors; C064525:glycine cleavage system; D000594:Amino Acid Oxidoreductases; D014166:Transferases