Purification and properties of 3-deoxy-D-arabionheptulosonic acid-7-phosphate synthetase (trp) from Escherichia coli.
The 3-deoxy-d-arabinoheptulosonic acid-7-phosphate synthetase which is subject to regulation by tryptophan has been partially purified from a strain of Escherichia coli K-12, in which this is the only functional form of this enzyme activity, and from a similar strain possessing a feedback-resistant form of the enzyme. Maximal observed inhibition by tryptophan of the feedback-sensitive enzyme was 56%. There was no evidence for cooperativity in the saturation of the enzyme with tryptophan or E4P. The molecular weights of the feedback-sensitive and feedback-resistant forms of the enzyme were the same (52,000), and no change was detected in the molecular weight of the feedback-sensitve enzyme in the presence of tryptophan. The effect of tryptophan analogues was tested to determine the nature of the tryptophan binding site. Treatment with ethylenediaminetetraacetic acid removed 80% of the activity of the feedback-sensitive enzyme. This activity was restored upon the addition of Co(2+) or Mn(2+). Neither treatment with ethylenediaminetetraacetic acid nor addition of Co(2+) or Mn(2+) affected the activity of the feedback-resistant enzyme.
D000446:Aldehyde-Lyases / Q000302:isolation & purification*; D000645:Ammonium Sulfate; D001089:Arabinose; D001426:Bacterial Proteins / Q000032:analysis; D002729:Chloromercuribenzoates / Q000494:pharmacology; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D003201:Computers; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000032:analysis / Q000201:enzymology* / Q000254:growth & development; D005246:Feedback; D006539:Heptoses; D006882:Hydroxyapatites; D007700:Kinetics; D008623:Mercaptoethanol / Q000494:pharmacology; D008970:Molecular Weight; D009696:Nucleic Acids / Q000302:isolation & purification; D010710:Phosphates; D010728:Phosphoenolpyruvate; D014364:Tryptophan / Q000031:analogs & derivatives / Q000494:pharmacology
D001426:Bacterial Proteins; D002729:Chloromercuribenzoates; D006539:Heptoses; D006882:Hydroxyapatites; D009696:Nucleic Acids; D010710:Phosphates; D008623:Mercaptoethanol; D010728:Phosphoenolpyruvate; D014364:Tryptophan; D004492:Edetic Acid; D001089:Arabinose; D000446:Aldehyde-Lyases; D000645:Ammonium Sulfate