DOMON domain of stromal cell-derived receptor 2 (ferric chelate reductase 1) and related proteins
Stromal cell-derived receptor 2 (or ferric chelate reductase 1) reduces Fe(3+) to Fe(2+) ahead of iron transport from the endosome to the cytoplasm. This transmembrane protein is a member of the cytochrome b561 family and contains a DOMON domain which may bind to heme or another ligand. DOMON-like domains can be found in all three kindgoms of life and are a diverse group of ligand binding domains that have been shown to interact with sugars and hemes. DOMON domains were initially thought to confer protein-protein interactions. They were subsequently found as a heme-binding motif in cellobiose dehydrogenase, an extracellular fungal oxidoreductase that degrades both lignin and cellulose, and in ethylbenzene dehydrogenase, an enzyme that aids in the anaerobic degradation of hydrocarbons. The domain interacts with sugars in the type 9 carbohydrate binding modules (CBM9), which are present in a variety of glycosyl hydrolases, and it can also be found at the N-terminus of sensor histidine kinases.
Jiyao W et al.(2023). "The conserved domain database in 2023.",