Cloning and characterization of argR, a gene that participates in regulation of arginine biosynthesis and catabolism in Pseudomonas aeruginosa PAO1
Autor: | Chung-Dar Lu, Seung-Moon Park, Ahmed T. Abdelal |
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Rok vydání: | 1997 |
Předmět: |
Arginine
Operon Recombinant Fusion Proteins Molecular Sequence Data Mutant lac operon Biology Microbiology chemistry.chemical_compound Bacterial Proteins Amino Acid Sequence Cloning Molecular Molecular Biology Ornithine Carbamoyltransferase Regulator gene Base Sequence Catabolism Sequence Analysis DNA Ornithine Repressor Proteins Models Chemical Biochemistry chemistry Genes Bacterial Mutation Pseudomonas aeruginosa Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) Transposon mutagenesis Acyltransferases Research Article |
Zdroj: | Journal of Bacteriology. 179:5300-5308 |
ISSN: | 1098-5530 0021-9193 |
DOI: | 10.1128/jb.179.17.5300-5308.1997 |
Popis: | Gel retardation experiments indicated the presence in Pseudomonas aeruginosa cell extracts of an arginine-inducible DNA-binding protein that interacts with the control regions for the car and argF operons, encoding carbamoylphosphate synthetase and anabolic ornithine carbamoyltransferase, respectively. Both enzymes are required for arginine biosynthesis. The use of a combination of transposon mutagenesis and arginine hydroxamate selection led to the isolation of a regulatory mutant that was impaired in the formation of the DNA-binding protein and in which the expression of an argF::lacZ fusion was not controlled by arginine. Experiments with various subclones led to the conclusion that the insertion affected the expression of an arginine regulatory gene, argR, that encodes a polypeptide with significant homology to the AraC/XylS family of regulatory proteins. Determination of the nucleotide sequence of the flanking regions showed that argR is the sixth and terminal gene of an operon for transport of arginine. The argR gene was inactivated by gene replacement, using a gentamicin cassette. Inactivation of argR abolished arginine control of the biosynthetic enzymes encoded by the car and argF operons. Furthermore, argR inactivation abolished the induction of several enzymes of the arginine succinyltransferase pathway, which is considered the major route for arginine catabolism under aerobic conditions. Consistent with this finding and unlike the parent strain, the argR::Gm derivative was unable to utilize arginine or ornithine as the sole carbon source. The combined data indicate a major role for ArgR in the control of arginine biosynthesis and aerobic catabolism. |
Databáze: | OpenAIRE |
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