ATP-dependent transporter that catalyzes the transport of a broad-spectrum of porphyrins from the cytoplasm to the extracellular space through the plasma membrane or into the vesicle lumen (By similarity). May also function as an ATP-dependent importer of porphyrins from the cytoplasm into the mitochondria, in turn may participate in the de novo heme biosynthesis regulation and in the coordination of heme and iron homeostasis during phenylhydrazine stress (By similarity). May play a key role in the early steps of melanogenesis producing PMEL amyloid fibrils (By similarity). In vitro, it confers to cells a resistance to toxic metal such as arsenic and cadmium and against chemotherapeutics agent such as 5-fluorouracil, SN-38 and vincristin (By similarity). In addition may play a role in the transition metal homeostasis (PubMed:18160489). ATP + H2O + heme b(in) = ADP + H(+) + heme b(out) + phosphate ATP + coproporphyrin III(in) + H2O = ADP + coproporphyrin III(out) + H(+) + phosphate ATP + H2O + pheophorbide a(in) = ADP + H(+) + pheophorbide a(out) + phosphate ATP + coproporphyrinogen III(in) + H2O = ADP + coproporphyrinogen III(out) + H(+) + phosphate ATP + H2O + protoporphyrin IX(in) = ADP + H(+) + phosphate + protoporphyrin IX(out) ATP + coproporphyrin I(in) + H2O = ADP + coproporphyrin I(out) + H(+) + phosphate ATP + H2O + uroporphyrin I(in) = ADP + H(+) + phosphate + uroporphyrin I(out) ATP + H2O + uroporphyrin III(in) = ADP + H(+) + phosphate + uroporphyrin III(out) Homodimer. Present in the membrane of mature erythrocytes and in exosomes released from reticulocytes during the final steps of erythroid maturation. Traffics from endoplasmic reticulum to Golgi during its glycans's maturation, therefrom is first targeted to the plasma membrane, and is rapidly internalized through endocytosis to be distributed to the limiting membrane of multivesicular bodies and lysosomes. Localized on the limiting membrane of early melanosomes of pigment cells (By similarity). Targeted to the endolysosomal compartment (PubMed:18160489). Ubiquitously expressed. Highly expressed in testis by meiotic pachytene spermatocytes and post-meiotic early spermatids. Contains two independently folding units, the N-terminal transmembrane domain (residues 1-205) and the ABC-core domain (206-842) are respectively responsible for the lysosomal targeting and the ATPase activity. N-glycosylated. Belongs to the ABC transporter superfamily. ABCB family. Heavy Metal importer (TC 3.A.1.210) subfamily. To date, the intracellular localization of ABCB6 is a matter of debate, with conflicting reports suggesting mitochondrial or endolysosomal localization, therefore questioning the requirement of ABCB6 in the mitochondrial import of porphyrins.