Properties of tyrosine-inhibitable 3-deoxy-d-arabinoheptulosonic acid-7-phosphate synthase from Salmonella.
Tyrosine-inhibitable 3-deoxy-D-arabinoheptulosonic acid-7-phosphate (DAHP) synthase was purified to homogeneity without significant loss of sensitivity to inhibition by tyrosine from an operator-constitutive strain (tyrOc) of Salmonella. The enzyme had an apparent molecular weight of 76,000 by gel filtration and a subunit molecular weight of 40,000 by sodium dodecyl sulfate-gel electrophoresis and by reaction with dimethyl suberimidate. It had an isoelectric point of 4.68. Inhibition by L-tyrosine showed a Hill coefficient of 1.8 at pH 7.0, suggesting cooperative interaction between tyrosine-binding sites, and was competitive with phosphoenol pyruvate and noncompetitive with erythrose-4-phosphate.
D010723:3-Deoxy-7-Phosphoheptulonate Synthase / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000446:Aldehyde-Lyases / Q000378:metabolism*; D001667:Binding, Competitive; D007526:Isoelectric Point; D008968:Molecular Conformation; D008970:Molecular Weight; D010728:Phosphoenolpyruvate / Q000031:analogs & derivatives / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000201:enzymology*; D013696:Temperature; D014443:Tyrosine / Q000494:pharmacology*
D014443:Tyrosine; D010728:Phosphoenolpyruvate; D010723:3-Deoxy-7-Phosphoheptulonate Synthase; D000446:Aldehyde-Lyases