mitochondrial inner membrane,
Mitochondrial ABC transporters are thought to play a key role in iron metabolism and heme biosynthesis. All mitochondrial ABC transporters described to date are of the half-transporter type and would probably function as dimers (Ramjeesingh et al. 2003) but their dimerization partners have not yet been identified. ABC7 is the functional human orthologue of yeast Atm1p (Csere et al. 1998), is predicted to dimerize in the same way as Atm1p (Chloupková et al. 2004) and is probably involved in iron homeostasis. Defects in ABCB7 are the cause of X-linked sideroblastic anemia with ataxia (ASAT) [MIM:301310] (Allikmets et al. 1999). Human genes ABCB8 and ABCB10 encode mABC1 and mABC2 respectively (Hogue et al. 1999, Zhang et al 2000 respectively). They would be expected to dimerize, as demonstrated for mABC2 (Graf et al. 2004). Both are believed to have similar functionality to ABC7 although this has not been demonstrated yet.