Probable dehydratase; part of the gene cluster that mediates the biosynthesis of hydroxamate-containing siderophores that play a critical role in virulence via intracellular iron acquisition during macrophage infection (PubMed:18404210). Siderophore biosynthesis. Expression is induced during iron deprivation (PubMed:18404210). Belongs to the short-chain dehydrogenases/reductases (SDR) family.