Metals such as iron and manganese are often essential for life, but toxic when in excess. It is therefore crucial that living organisms regulate their cellular metal levels to allow their use as co-factors for vital metalloenzymes, but prevent excess free metals which can drive reactive chemistry and cause cellular damage.

We use molecular microbiology and protein biochemistry to study how abundant and important bacteria, such as nitrogen-fixing rhizobia and marine roseobacters, obtain, store metals and exert metal homeostasis. These rhizobia and roseobacters lack the typical global regulators of iron metabolism that function in E. coli, and can instead utilise two complementary acting regulators termed the Iron Response Regulator (Irr) and Rhizobium iron regulator (RirA), see Figure.