CYB5R3:FAD reduces CYB5A:ferriheme to CYB5A:heme

Cytochrome b5 reductase (CYB5R3) catalyzes the reduction of cytosolic ferric CYB5A (CYB5A:ferriheme) to ferrous CYPB5A (CYB5A:heme), coupled to the conversion of NADH to NAD+ (Shirabe et al. 1995). CYB5R3 is associated with the outer mitochondrial membrane via a myristoyl group added post-translationally to glycine residue 2 of the protein (Borgese et al. 1993).

细胞色素b5还原酶（CYB5R3）催化细胞质中铁离子形式的细胞色素b5A（CYB5A:ferriheme）还原为亚铁形式的CYPB5A（CYB5A:heme），此过程与NADH转化为NAD+的氧化还原反应相偶联（Shirabe等，1995年）。CYB5R3通过在蛋白质的甘氨酸残基2位置后翻译修饰的肉豆蔻酰基团与线粒体外膜相连接（Borgese等，1993年）。