title: Biosynthesis of enterochelin in Escherichia coli K-12: separation of the polypeptides coded for by the entD, E, F and G genes.
abstract: Four enzymic components, coded for by the entD, entE, entF and entG genes, involved in the biosynthesis of enterochelin from 2,3-dihydroxybenzoate have been separated from cell extracts of mutant strains of Escherichia coli K-12. The starting material for fractionation of the E, F and G components was a cell extract of an entD mutant strain, which yielded the E, F and G enzymic components uncontaminated by a functional D component. The D component was isolated from cell extracts of an entE mutant strain. The conversion of 2,3-dihydroxybenzoate and L-serine into enterochelin is dependent on the presence of all four enzymic components. The E and F components were shown to catalyze ATP-pyrophosphate exchange reactions dependent on 2,3-dihydroxybenzoate and L-serine, respectively, whereas fractionated extracts of the entE and entF mutant strains lacked these reactions. These data provide firm evidence that the E and F components are involved in the initial activation of the substrates. The D and G components are necessary for subsequent and, as yet, undefinedd reactions.
mesh_terms: D000249:Adenosine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D011756:Diphosphates / Q000378:metabolism; D004758:Enterobactin / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005796:Genes; D010455:Peptides / Q000235:genetics* / Q000302:isolation & purification; D012694:Serine / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D011756:Diphosphates; D010455:Peptides; D004758:Enterobactin; D000249:Adenosine Monophosphate; D012694:Serine; D000255:Adenosine Triphosphate