Human FBXL5 (F-box and leucine-rich repeat protein 5) protein plays a role in cellular iron homeostasis. It is part of an E3 ubiquitin ligase complex that targets the iron regulatory protein IRP2 for proteasomal degradation. The FBXL5's stability is regulated by iron concentration, with its iron- and oxygen-binding hemerythrin domain acting as a ligand-dependent regulatory switch.
Jiyao W et al.(2023). "The conserved domain database in 2023.",