Eukaryotic cytochrome b(561), including the FRRS1 gene product
Cytochrome b(561), as found in eukaryotes, similar to and including the human FRRS1 gene product (ferric-chelate reductase 1), also called SDR-2 (stromal cell-derived receptor 2). This family comprises a variety of domain architectures, many of which contain dopamine beta-monooxygenase (DOMON) domains. The protein might act as a ferric-chelate reductase, catalyzing the reduction of Fe(3+) to Fe(2+), such as associated with the transport of iron from the endosome to the cytoplasm. It is assumed that this protein uses ascorbate as the electron donor. Belongs to the cytochrome b(561) family, which are secretory vesicle-specific electron transport proteins. Cytochromes b(561) are integral membrane proteins that bind two heme groups non-covalently, and may have six alpha-helical trans-membrane segments.