Ferric reductase involved in adaptation to iron starvation and which is most likely part of the reductive iron assimilatory system (RIA), a siderophore-independent high affinity iron uptake mechanism (PubMed:21840411). Expression is repressed by iron in a sreA- and acuM-mediated way (PubMed:21062375, PubMed:21840411). Reduces ferrireductase activity and decreases biomass production during iron starvation but not during iron and copper sufficiency and copper starvation (PubMed:21840411). Increases sensitivity to hydrogen peroxide (PubMed:21840411). Belongs to the ferric reductase (FRE) family.