This C-terminal domain appears to be a dimerization domain of the mitochondrial apoptosis-inducing factor 1. protein. The domain also appears at the C-terminus of FAD-dependent pyridine nucleotide-disulfide oxidoreductases. Apoptosis inducing factor (AIF) is a bifunctional mitochondrial flavoprotein critical for energy metabolizm and induction of caspase-independent apoptosis. On reduction with NADH, AIF undergoes dimerization and forms tight, long-lived FADH2-NAD charge-transfer complexes proposed to be functionally important.
Jiyao W et al.(2023). "The conserved domain database in 2023.",