Transcriptional repressor that binds the consensus promoter sequence 5'-[AT]GATAA-3' during iron-replete conditions to down-regulate transcription of target genes (PubMed:11956219, PubMed:25733668). Represses the expression of the iron transporter fio1 in response to high iron concentrations (PubMed:11956219, PubMed:25733668). Also represses the expression of str1, str2 and str3 (PubMed:12888492, PubMed:29549126). Represses the expression of shu1 in presence of iron (PubMed:25733668). Activated by iron. Interacts with tup11.