This entry includes CYB561D1/2 from humans. CYB561D2 (also known as 101F6), a cytochrome b561 homologue, is a transmembrane reductase that may use ascorbate as an electron donor in the cytoplasm and transfer electrons across endoplasmic reticulum membranes to reduce monodehydro-L-ascorbate radical and iron cations Fe3 in the lumen of that compartment []. The function of CYB561D1 is not clear. This entry also includes cytochrome b561 domain-containing proteins such as At4g18260 and At2g30890 from Arabidopsis [].
