ID:ABCB6_HUMAN DESCRIPTION: RecName: Full=ATP-binding cassette sub-family B member 6, mitochondrial; AltName: Full=Mitochondrial ABC transporter 3; Short=Mt-ABC transporter 3; AltName: Full=P-glycoprotein-related protein; AltName: Full=Ubiquitously-expressed mammalian ABC half transporter; FUNCTION: Binds heme and porphyrins and functions in their ATP- dependent uptake into the mitochondria. Plays a crucial role in heme synthesis. SUBUNIT: Homodimer. SUBCELLULAR LOCATION: Cell membrane. Mitochondrion outer membrane; Multi-pass membrane protein. Endoplasmic reticulum. Golgi apparatus. TISSUE SPECIFICITY: Widely expressed. High expression is detected in the retinal epithelium. DEVELOPMENTAL STAGE: Highly expressed in fetal liver. INDUCTION: Up-regulated by cellular porphyrins (at protein level). POLYMORPHISM: Genetic variations in ABCB6 define the Langereis blood group system (LAN) [MIM:111600]. Individuals with Lan(-) blood group lack the Lan antigen on their red blood cells. These individuals may have anti-Lan antibodies in their serum, which can cause transfusion reactions or hemolytic disease of the fetus or newborn. The Lan(-) blood group is only clinically significant in transfusion settings or during pregnancy; otherwise Lan(-) individuals have no clinical features. DISEASE: Defects in ABCB6 are the cause of microphthalmia, isolated, with coloboma, type 7 (MCOPCB7) [MIM:614497]. A disorder of eye formation, ranging from small size of a single eye to complete bilateral absence of ocular tissues. Ocular abnormalities like opacities of the cornea and lens, scaring of the retina and choroid, cataract and other abnormalities like cataract may also be present. Ocular colobomas are a set of malformations resulting from abnormal morphogenesis of the optic cup and stalk, and the fusion of the fetal fissure (optic fissure). MISCELLANEOUS: Depletion of Abcb6 by RNAi abrogates heme biosynthesis. Overexpression enhances porphyrin biosynthesis. SIMILARITY: Belongs to the ABC transporter superfamily. ABCB family. Heavy Metal importer (TC 3.A.1.210) subfamily. SIMILARITY: Contains 1 ABC transmembrane type-1 domain. SIMILARITY: Contains 1 ABC transporter domain. SEQUENCE CAUTION: Sequence=AAG33617.1; Type=Erroneous initiation; Sequence=AAG33618.1; Type=Erroneous initiation; Sequence=AAH43423.1; Type=Miscellaneous discrepancy; Note=Intron retention; Sequence=BAD18782.1; Type=Erroneous termination; Positions=168; Note=Translated as Trp; Sequence=BAD92291.1; Type=Miscellaneous discrepancy; Note=Chimeric cDNA; WEB RESOURCE: Name=ABCMdb; Note=Database for mutations in ABC proteins; URL="http://abcmutations.hegelab.org/proteinDetails?uniprot_id=Q9NP58";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on Q9NP58
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
Gene Ontology (GO) Annotations with Structured Vocabulary
Molecular Function: GO:0000166 nucleotide binding GO:0005524 ATP binding GO:0015232 heme transporter activity GO:0015439 heme-transporting ATPase activity GO:0015562 efflux transmembrane transporter activity GO:0016887 ATPase activity GO:0020037 heme binding GO:0042626 ATPase activity, coupled to transmembrane movement of substances
Biological Process: GO:0006779 porphyrin-containing compound biosynthetic process GO:0006879 cellular iron ion homeostasis GO:0007420 brain development GO:0015886 heme transport GO:0043588 skin development GO:0055085 transmembrane transport
U66673 - Homo sapiens clone EST45597 mRNA sequence. BC043423 - Homo sapiens ATP-binding cassette, sub-family B (MDR/TAP), member 6, mRNA (cDNA clone IMAGE:5288180), complete cds. AF070598 - Homo sapiens clone 24410 ABC transporter mRNA, partial cds. AK026067 - Homo sapiens cDNA: FLJ22414 fis, clone HRC08477, highly similar to AF070598 Homo sapiens clone 24410 ABC transporter mRNA. AK172812 - Homo sapiens cDNA FLJ23973 fis, clone HEP18305, highly similar to ATP-binding cassette, sub-family B, member 6, mitochondrial precursor. AK057026 - Homo sapiens cDNA FLJ32464 fis, clone SKNMC1000251, highly similar to Homo sapiens MT-ABC transporter (MTABC) mRNA. AF308472 - Homo sapiens ATP-binding cassette half-transporter (PRP) mRNA, complete cds. BC000559 - Homo sapiens ATP-binding cassette, sub-family B (MDR/TAP), member 6, mRNA (cDNA clone MGC:3021 IMAGE:3162881), complete cds. AB209054 - Homo sapiens mRNA for ATP-binding cassette, sub-family B, member 6 variant protein. AJ289233 - Homo sapiens mRNA for ABC transporter umat (ABCB6 gene). JD326550 - Sequence 307574 from Patent EP1572962. JD312888 - Sequence 293912 from Patent EP1572962. AF076775 - Homo sapiens MT-ABC transporter (MTABC) mRNA, complete cds. KJ904642 - Synthetic construct Homo sapiens clone ccsbBroadEn_14036 ABCB6 gene, encodes complete protein. DQ891876 - Synthetic construct clone IMAGE:100004506; FLH180836.01X; RZPDo839G07134D ATP-binding cassette, sub-family B (MDR/TAP), member 6 (ABCB6) gene, encodes complete protein. DQ895063 - Synthetic construct Homo sapiens clone IMAGE:100009523; FLH180832.01L; RZPDo839G07133D ATP-binding cassette, sub-family B (MDR/TAP), member 6 (ABCB6) gene, encodes complete protein. AK303230 - Homo sapiens cDNA FLJ61508 complete cds, moderately similar to ATP-binding cassette sub-family B member 6, mitochondrial precursor. CU674272 - Synthetic construct Homo sapiens gateway clone IMAGE:100020508 5' read ABCB6 mRNA. LP896216 - Sequence 1080 from Patent EP3253886. JD019642 - Sequence 666 from Patent EP1572962. JD035454 - Sequence 16478 from Patent EP1572962. DQ573157 - Homo sapiens piRNA piR-41269, complete sequence. JD077864 - Sequence 58888 from Patent EP1572962. JD217108 - Sequence 198132 from Patent EP1572962.
Biochemical and Signaling Pathways
KEGG - Kyoto Encyclopedia of Genes and Genomes hsa02010 - ABC transporters
Reactome (by CSHL, EBI, and GO)
Protein Q9NP58 (Reactome details) participates in the following event(s):
R-HSA-1369065 ABCB6 transports porphyrin from cytosol to mitchondrial matrix R-HSA-1369007 Mitochondrial ABC transporters R-HSA-382556 ABC-family proteins mediated transport R-HSA-382551 Transport of small molecules
Sequence and Links to Tools and Databases 
Microarray Expression Data 
