5.B.2.2.7
Cytochrome b₅₆₁ and DOMON domain-containing protein, At4g12980, of 394 aas and 5 C-terminal TMSs. It may act as a catecholamine-responsive trans-membrane electron transporter (Verelst and Asard 2004). Tonoplast cytochrome b₅₆₁ is a transmembrane ascorbate-dependent monodehydroascorbate reductase with two heme b groups bound non-covalently. It may be involved in catecholamine biochemistry in plants. It may catalyze transmembrane proton transport (Bérczi et al. 2023). Cytb₅₆₁ is essential for cellular redox balance and metabolism, facilitating electron transport across membranes and supporting processes such as iron homeostasis, stress defence, and cell wall modifications, highlighting their fundamental role in plant physiology (Tosato et al. 2025).