View source for 7tw2


==Cryo-EM structure of human band 3 dimer from red blood cell==
<StructureSection load='7tw2' size='340' side='right'caption='[[7tw2]], [[Resolution|resolution]] 4.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7tw2]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7TW2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7TW2 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 4.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7tw2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7tw2 OCA], [https://pdbe.org/7tw2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7tw2 RCSB], [https://www.ebi.ac.uk/pdbsum/7tw2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7tw2 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/B3AT_HUMAN B3AT_HUMAN] Defects in SLC4A1 are the cause of elliptocytosis type 4 (EL4) [MIM:[https://omim.org/entry/109270 109270]. EL4 is a Rhesus-unlinked form of hereditary elliptocytosis, a genetically heterogeneous, autosomal dominant hematologic disorder. It is characterized by variable hemolytic anemia and elliptical or oval red cell shape.<ref>PMID:1722314</ref> <ref>PMID:1538405</ref>   Defects in SLC4A1 are the cause of spherocytosis type 4 (SPH4) [MIM:[https://omim.org/entry/612653 612653]; also known as hereditary spherocytosis type 4 (HS4). Spherocytosis is a hematologic disorder leading to chronic hemolytic anemia and characterized by numerous abnormally shaped erythrocytes which are generally spheroidal.<ref>PMID:8547122</ref> <ref>PMID:1378323</ref> <ref>PMID:7530501</ref> <ref>PMID:8943874</ref> <ref>PMID:8640229</ref> <ref>PMID:9207478</ref> <ref>PMID:9012689</ref> <ref>PMID:9233560</ref> <ref>PMID:9973643</ref> <ref>PMID:10580570</ref> <ref>PMID:10942416</ref> <ref>PMID:10745622</ref> <ref>PMID:11380459</ref> <ref>PMID:15813913</ref> <ref>PMID:16227998</ref>   Defects in SLC4A1 are the cause of renal tubular acidosis, distal, autosomal dominant (AD-dRTA) [MIM:[https://omim.org/entry/179800 179800]. A disease characterized by reduced ability to acidify urine, variable hyperchloremic hypokalemic metabolic acidosis, nephrocalcinosis, and nephrolithiasis.  Defects in SLC4A1 are the cause of renal tubular acidosis, distal, with hemolytic anemia (dRTA-HA) [MIM:[https://omim.org/entry/611590 611590]. A disease characterized by the association of hemolytic anemia with distal renal tubular acidosis, the reduced ability to acidify urine resulting in variable hyperchloremic hypokalemic metabolic acidosis, nephrocalcinosis, and nephrolithiasis.  Defects in SLC4A1 are the cause of renal tubular acidosis, distal, with normal red cell morphology (dRTA-NRC) [MIM:[https://omim.org/entry/611590 611590]. A disease characterized by reduced ability to acidify urine, variable hyperchloremic hypokalemic metabolic acidosis, nephrocalcinosis, and nephrolithiasis.
== Function ==
[https://www.uniprot.org/uniprot/B3AT_HUMAN B3AT_HUMAN] Band 3 is the major integral glycoprotein of the erythrocyte membrane. Band 3 has two functional domains. Its integral domain mediates a 1:1 exchange of inorganic anions across the membrane, whereas its cytoplasmic domain provides binding sites for cytoskeletal proteins, glycolytic enzymes, and hemoglobin.
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== Publication Abstract from PubMed ==
The cytoskeleton of a red blood cell (RBC) is anchored to the cell membrane by the ankyrin complex. This complex is assembled during RBC genesis and comprises primarily band 3, protein 4.2 and ankyrin, whose mutations contribute to numerous human inherited diseases. High-resolution structures of the ankyrin complex have been long sought-after to understand its assembly and disease-causing mutations. Here, we analyzed native complexes on the human RBC membrane by stepwise fractionation. Cryo-electron microscopy structures of nine band-3-associated complexes reveal that protein 4.2 stabilizes the cytoplasmic domain of band 3 dimer. In turn, the superhelix-shaped ankyrin binds to this protein 4.2 via ankyrin repeats (ARs) 6-13 and to another band 3 dimer via ARs 17-20, bridging two band 3 dimers in the ankyrin complex. Integration of these structures with both prior data and our biochemical data supports a model of ankyrin complex assembly during erythropoiesis and identifies interactions essential for the mechanical stability of RBC.

Structure, dynamics and assembly of the ankyrin complex on human red blood cell membrane.,Xia X, Liu S, Zhou ZH Nat Struct Mol Biol. 2022 Jul;29(7):698-705. doi: 10.1038/s41594-022-00779-7. , Epub 2022 Jun 2. PMID:35655099<ref>PMID:35655099</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7tw2" style="background-color:#fffaf0;"></div>

==See Also==
*[[Anion exchange protein 3D structures|Anion exchange protein 3D structures]]
*[[Ankyrin 3D structures|Ankyrin 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Liu SH]]
[[Category: Xia X]]
[[Category: Zhou ZH]]