Iron is a critical element for the physiology of nearly all known organisms. Hypersaline environments are typically iron deficient, but it remains unclear how halophiles regulate iron homeostasis. Recently we found that two DtxR family transcription factors, Idr1 and Idr2, work together to regulate iron homeostasis (Schmid et al., 2011). This project takes a comparative approach to investigate the conservation of such coordinate control across different species of halophiles.