ATP-binding subunit of the mitochondrial potassium channel located in the mitochondrial inner membrane (PubMed:31435016). Together with CCDC51/MITOK, forms a protein complex localized in the mitochondria that mediates ATP-dependent potassium currents across the inner membrane (that is, mitoK(ATP) channel) (PubMed:31435016). Plays a role in mitochondrial iron transport (PubMed:30623799). Required for maintenance of normal cardiac function, possibly by influencing mitochondrial iron export and regulating the maturation of cytosolic iron sulfur cluster-containing enzymes (By similarity). Channel activity inhibited by ATP via ABCB8/MITOSUR subunit. The mitochondrial potassium channel (mitoK(ATP)) is composed of 4 subunits of CCDC51/MITOK and 4 subunits of ABCB8/MITOSUR (Probable). Interacts with C10orf88/PAAT (PubMed:25063848). Interacts with NRP1; NRP1 regulates ABCB8/MITOSUR protein levels in mitochondria (PubMed:30623799). Ubiquitous. SP1 transcription factor binds to the ABCB8 core promoter region, possibly regulating its transcription. Belongs to the ABC transporter superfamily. ABCB family. Multidrug resistance exporter (TC 3.A.1.201) subfamily. Database for mutations in ABC proteins