Building nicotianamine-based metallophores in bacteria

Nicotianamine is a metabolite present in all plants and fungi where it is implicated in the homeostasis of different micronutrients such as iron, nickel or zinc. In some plants it also serves as a precursor of phytosiderophores that are used for extracellular iron scavenging. More recently, opine-type metallophore homologues to nicotianamine were uncovered in Staphylococcus aureus and Pseudomonas aeruginosa. Here I will review the recent literature about the discovery, role and regulation of these bacterial metallophores. The phylogeny of the central enzyme responsible for these metallophores biosynthesis in plants, archaea and bacteria will also be discussed, establishing the old root of nicotianamine.