Derepression of certain aromatic amino acid biosynthetic enzymes of Escherichia coli K-12 by growth in Fe3+-deficient medium.
3-Deoxy-arabino-heptulosonic acid 7-phosphate synthase, prephenate dehydratase, tryptophan synthase, and 2,3-dihydroxybenzoylserine synthase enzyme activities are derepressed in wild-type Escherichia coli K-12 cells grown on Fe3+-deficient medium. This derepression is reversed when FeSO4 is added to the growth medium. Addition of shikimic acid to the Fe3+-deficient growth medium caused repression of the first three enzyme activities but not of 2,3-dihydroxybenzoylserine synthase activity. Addition of 2,3-dihydroxybenzoic acid to the Fe3+-deficient growth medium has no effect on any of the above-mentioned enzyme activities. The Fe3+ deficiency-mediated derepression of 3-deoxyarabino-heptulosonic acid 7-phosphate synthase activity is due to an elevation of the tyrosine-sensitive isoenzyme; the phenylalanine-sensitive isoenzyme is not derepressed under these conditions.
D010723:3-Deoxy-7-Phosphoheptulonate Synthase / Q000378:metabolism*; D000446:Aldehyde-Lyases / Q000378:metabolism*; D002474:Cell-Free System; D003470:Culture Media; D004794:Enzyme Repression; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D005970:Glutamate Synthase / Q000378:metabolism; D006836:Hydro-Lyases / Q000378:metabolism*; D062385:Hydroxybenzoates / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D010453:Peptide Synthases / Q000378:metabolism*; D010649:Phenylalanine / Q000096:biosynthesis; D011302:Prephenate Dehydratase / Q000378:metabolism*; D012765:Shikimic Acid / Q000378:metabolism; D014364:Tryptophan / Q000096:biosynthesis; D014367:Tryptophan Synthase / Q000378:metabolism*; D014443:Tyrosine / Q000096:biosynthesis
D003470:Culture Media; D062385:Hydroxybenzoates; D007527:Isoenzymes; D012765:Shikimic Acid; D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D007501:Iron; D005970:Glutamate Synthase; D005969:Glutamate Dehydrogenase; D010723:3-Deoxy-7-Phosphoheptulonate Synthase; D000446:Aldehyde-Lyases; D006836:Hydro-Lyases; D014367:Tryptophan Synthase; D011302:Prephenate Dehydratase; D010453:Peptide Synthases