<p>This reductase is found associated with gene clusters for the biosynthesis of various non-ribosomal peptide derived natural products in which cysteine is cyclised to a thiazoline ring containing an imide double bond. Examples include yersiniabactin and pyochelin. Yersiniabactin is a virulence factor secreted by <taxon tax_id="632">Yersinia pestis</taxon> in iron-deficient microenvironments, in order to scavenge ferric ions [<cite idref="PUB00013137"/>]. </p>