View source for 1nqp

==Crystal structure of Human hemoglobin E at 1.73 A resolution==
<StructureSection load='1nqp' size='340' side='right' caption='[[1nqp]], [[Resolution|resolution]] 1.73&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1nqp]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NQP OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1NQP FirstGlance]. <br>
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CYN:CYANIDE+ION'>CYN</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene><br>
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1bbb|1bbb]]</td></tr>
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1nqp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nqp OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1nqp RCSB], [http://www.ebi.ac.uk/pdbsum/1nqp PDBsum]</span></td></tr>
<table>
== Disease ==
[[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref> <ref>PMID:6259091</ref> <ref>PMID:2599881</ref> <ref>PMID:8704193</ref>   Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[http://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref>   Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[http://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues.  Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[http://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>  
== Function ==
[[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues.<ref>PMID:16904236</ref>   LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.<ref>PMID:16904236</ref>  
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/nq/1nqp_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Hemoglobin A(2) (alpha(2)delta(2)), a minor (2-3%) component of circulating red blood cells, acts as an anti-sickling agent and its elevated concentration in beta-thalassemia is a useful clinical diagnostic. In beta-thalassemia major, where there is a failure of beta-chain production, HbA(2) acts as the predominant oxygen delivery mechanism. Hemoglobin E, is another common abnormal hemoglobin, caused by splice site mutation in exon 1 of beta globin gene, when combines with beta-thalassemia, causes severe microcytic anemia. The purification, crystallization, and preliminary structural studies of HbA(2) and HbE are reported here. HbA(2) and HbE are purified by cation exchange column chromatography in presence of KCN from the blood samples of individuals suffering from beta-thalassemia minor and E beta-thalassemia. X-ray diffraction data of HbA(2) and HbE were collected upto 2.1 and 1.73 A, respectively. HbA(2) crystallized in space group P2(1) with unit cell parameters a=54.33 A, b=83.73 A, c=62.87 A, and beta=99.80 degrees whereas HbE crystallized in space group P2(1)2(1)2(1) with unit cell parameters a=60.89 A, b=95.81 A, and c=99.08 A. Asymmetric unit in each case contains one Hb tetramer in R(2) state.

Crystallization and preliminary X-ray structural studies of hemoglobin A2 and hemoglobin E, isolated from the blood samples of beta-thalassemic patients.,Dasgupta J, Sen U, Choudhury D, Datta P, Chakrabarti A, Chakrabarty SB, Chakrabarty A, Dattagupta JK Biochem Biophys Res Commun. 2003 Apr 4;303(2):619-23. PMID:12659864<ref>PMID:12659864</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>

==See Also==
*[[Hemoglobin 3D structures|Hemoglobin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Basu, S.]]
[[Category: Chakrabarti, A.]]
[[Category: Chakrabarty, A.]]
[[Category: Choudhury, D.]]
[[Category: Dasgupta, J.]]
[[Category: Dattagupta, J K.]]
[[Category: Dutta, P.]]
[[Category: Sen, U.]]
[[Category: Hemoglobin e oxygen transport beta thalassemia]]
[[Category: Oxygen storage-transport complex]]