Direct evidence for the participation of pyruvate in N-hydroxylation of lysine

The contribution of pyruvate to the formation of N6-acetyl-N6-hydroxylysine by a cell-free system of Aerobacter aerogenes 62-1 involved in the production of the dihydroxamate siderophore, aerobactin, has been assessed by a study of the influence of its analogs as well as of inhibitors of thiamine pyrophosphate-dependent decarboxylation reactions. These studies have provided unequivocal evidence for pyruvate functioning not only as a source of reducing equivalents in the initial step of N-hydroxylation of lysine but also as a precursor of the acetyl moiety in the subsequent conversion of the N-hydroxy amino to its N6-acetyl derivative.