Mutational analysis of the feedback sites of lysine-sensitive aspartokinase of Escherichia coli.
In Escherichia coli, thrA, metLM, and lysC encode aspartokinase isozymes that show feedback inhibition by threonine, methionine, and lysine, respectively. In vitro chemical mutagenesis of the cloned lysC gene was used to identify residues and regions of the polypeptide essential for feedback inhibition by lysine. The isolated lysine-insensitive mutants were demonstrated to have missense mutations in amino acid residues 323-352, and at position 250 of aspartokinase III.
Kikuchi
Y
Y
Central Research Laboratories, Ajinomoto Co., Inc., Kawasaki, Japan. clx_kikuti@te10.ajinomoto.co.jp
Kojima
H
H
Tanaka
T
T
D000595:Amino Acid Sequence; D001222:Aspartate Kinase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004252:DNA Mutational Analysis; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D005246:Feedback / Q000187:drug effects; D015964:Gene Expression Regulation, Bacterial; D019811:Hydroxylamine / Q000494:pharmacology; D008239:Lysine / Q000096:biosynthesis / Q000494:pharmacology*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010957:Plasmids / Q000187:drug effects / Q000235:genetics
D019811:Hydroxylamine; D001222:Aspartate Kinase; D008239:Lysine