Transcriptional repressor that regulates hypoxic genes during normoxia; involved in aerobic repression of genes such as COX5b, TIR1, and HEM13; binds DNA intrastrand cross-links formed by cisplatin; contains two HMG (high mobility group) box domains that bind and bend cisplatin-modified DNA, blocking excision repair; N-terminal intrinsically disordered region forms amyloid fibrils in vitro and prion-like aggregates in vivo; IXR1 has a paralog, ABF2, that arose from the whole genome duplication