View source for 2zs0


==Structural Basis for the Heterotropic and Homotropic Interactions of Invertebrate Giant Hemoglobin==
<StructureSection load='2zs0' size='340' side='right'caption='[[2zs0]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2zs0]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Oligobrachia_mashikoi Oligobrachia mashikoi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ZS0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ZS0 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=OXY:OXYGEN+MOLECULE'>OXY</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=2zs0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zs0 OCA], [https://pdbe.org/2zs0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2zs0 RCSB], [https://www.ebi.ac.uk/pdbsum/2zs0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2zs0 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GLBA1_OLIMA GLBA1_OLIMA] The extracellular giant hemoglobin is able to bind and transport oxygen and hydrosulfide simultaneously and reversibly at two different sites.
== 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/zs/2zs0_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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/main_output.php?pdb_ID=2zs0 ConSurf].
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== Publication Abstract from PubMed ==
The oxygen binding properties of extracellular giant hemoglobins (Hbs) in some annelids exhibit features significantly different from those of vertebrate tetrameric Hbs. Annelid giant Hbs show cooperative oxygen binding properties in the presence of inorganic cations, while the cooperativities of vertebrate Hbs are enhanced by small organic anions or chloride ions. To elucidate the structural basis for the cation-mediated cooperative mechanisms of these giant Hbs, we determined the crystal structures of Ca (2+)- and Mg (2+)-bound Hbs from Oligobrachia mashikoi at 1.6 and 1.7 A resolution, respectively. Both of the metal-bound structures were determined in the oxygenated state. Four Ca (2+)-binding sites and one Mg (2+)-binding site were identified in each tetramer subassembly. These cations are considered to stabilize the oxygenated form and increase affinity and cooperativity for oxygen binding, as almost all of the Ca (2+) and Mg (2+) cations were bound at the interface regions, forming either direct or hydrogen bond-mediated interactions with the neighboring subunits. A comparison of the structures of the oxygenated form and the partially unliganded form provides structural insight into proton-coupled cooperativity (Bohr effect) and ligand-induced transitions. Two histidine residues are assumed to be primarily associated with the Bohr effect. With regard to the ligand-induced cooperativity, a novel quaternary rotation mechanism is proposed to exist at the interface region of the dimer subassembly. Interactions among conserved residues Arg E10, His F3, Gln F7, and Val E11, together with the bending motion of the heme molecules, appear to be essential for quaternary rearrangement.

Structural Basis for the Heterotropic and Homotropic Interactions of Invertebrate Giant Hemoglobin.,Numoto N, Nakagawa T, Kita A, Sasayama Y, Fukumori Y, Miki K Biochemistry. 2008 Oct 4. PMID:18834142<ref>PMID:18834142</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2zs0" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemoglobin 3D structures|Hemoglobin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Oligobrachia mashikoi]]
[[Category: Fukumori Y]]
[[Category: Kita A]]
[[Category: Miki K]]
[[Category: Nakagawa T]]
[[Category: Numoto N]]
[[Category: Sasayama Y]]