Siderophore Evolution and Functional Pathway Swapping in the Marine Actinomycete Genus Salinispora

The marine actinomycete genus Salinispora is a prolific producer of secondary metabolites including the anti-cancer compound salinosporamide A. Recent genome mining efforts revealed an enormous diversity of cryptic natural product pathways that provide not only opportunities to guide natural product discovery and engineering, but offer unprecedented access into the evolutionary processes that create secondary metabolite structural diversity.

Here we present the evolutionary history of siderophore pathways in Salinispora. These compounds are important molecules for the sequestration of iron in bacteria and have been shown to play an essential role for the survival of an organism under iron-limiting conditions. Our example shows the enormous plasticity of secondary metabolite gene clusters and introduces the idea of functional pathway swapping in bacteria.