Precursor activation in a pyoverdine biosynthesis.

The siderophore produced by Azotobacter vinelandii strain UW belongs to a large family of peptidic siderophores collectively called pyoverdines. The biosynthesis of the peptidyl moiety of this siderophore was shown to involve activation of the constituent amino acids as their adenylates, as demonstrated by amino acid-dependent ATP-[32P]pyrophosphate exchange. The enzyme system responsible for this activation was partially purified by chromatographic techniques.