GATA-type transcription repressor that regulates iron- acquisition genes through specific binding the GATA sequence elements of target promoters in a zinc-dependent manner (PubMed:9790585, PubMed:10194352, PubMed:12484767). Iron acquisition regulation is critical for survival under both iron-limiting conditions (to acquire essential iron) and iron-replete conditions (to limit iron toxicity) (PubMed:10194352). Represses the synthesis of siderophores in high iron conditions (PubMed:9790585). The promoter contains a number of GATA sequences; however, expression occurs in a constitutive fashion and is not regulated by the concentration of iron available to the cells (PubMed:9790585). The conserved cystein-rich region (CRR) localized between the zinc fingers is also involved in DNA-binding and transcription repressor activity (PubMed:12484767). Both the N-terminal and C-terminal zinc fingers are involved in DNA-binding, although the C-terminal finger plays a more important role in the binding (PubMed:10194352). Derepresses siderophore biosynthesis in high iron concentrations (PubMed:9790585).