View source for 2gnw


==Crystal structure of non-symbiotic plant hemoglobin from rice, B10 mutant F40W==
<StructureSection load='2gnw' size='340' side='right'caption='[[2gnw]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2gnw]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Orysa Orysa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GNW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2GNW FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[2gnv|2gnv]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HB1, GLB1A ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4530 ORYSA])</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=2gnw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2gnw OCA], [https://pdbe.org/2gnw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2gnw RCSB], [https://www.ebi.ac.uk/pdbsum/2gnw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2gnw ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/HBL1_ORYSJ HBL1_ORYSJ]] May not function as an oxygen storage or transport protein, but might act as an oxygen sensor or play a role in electron transfer, possibly to a bound oxygen molecule. Has an unusually high affinity for O(2) because of a very low dissociation constant. 
== 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/gn/2gnw_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/main_output.php?pdb_ID=2gnw ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
All plants contain an unusual class of hemoglobins that display bis-histidyl coordination yet are able to bind exogenous ligands such as oxygen. Structurally homologous hexacoordinate hemoglobins (hxHbs) are also found in animals (neuroglobin and cytoglobin) and some cyanobacteria, where they are thought to play a role in free radical scavenging or ligand sensing. The plant hxHbs can be distinguished from the others because they are only weakly hexcacoordinate in the ferrous state, yet no structural mechanism for regulating hexacoordination has been articulated to account for this behavior. Plant hxHbs contain a conserved Phe at position B10 (Phe(B10)), which is near the reversibly coordinated distal His(E7). We have investigated the effects of Phe(B10) mutation on kinetic and equilibrium constants for hexacoordination and exogenous ligand binding in the ferrous and ferric oxidation states. Kinetic and equilibrium constants for hexacoordination and ligand binding along with CO-FTIR spectroscopy, midpoint reduction potentials, and the crystal structures of two key mutant proteins (F40W and F40L) reveal that Phe(B10) is an important regulatory element in hexacoordination. We show that Phe at this position is the only amino acid that facilitates stable oxygen binding to the ferrous Hb and the only one that promotes ligand binding in the ferric oxidation states. This work presents a structural mechanism for regulating reversible intramolecular coordination in plant hxHbs.

Role of phenylalanine B10 in plant nonsymbiotic hemoglobins.,Smagghe BJ, Kundu S, Hoy JA, Halder P, Weiland TR, Savage A, Venugopal A, Goodman M, Premer S, Hargrove MS Biochemistry. 2006 Aug 15;45(32):9735-45. PMID:16893175<ref>PMID:16893175</ref>

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

==See Also==
*[[Hemoglobin 3D structures|Hemoglobin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Orysa]]
[[Category: Hoy, J A]]
[[Category: On 2 helical fold]]
[[Category: Globin]]
[[Category: Heme]]
[[Category: Hemoglobin]]
[[Category: Hexacoordinate]]
[[Category: Iron]]
[[Category: Nonsymbiotic]]
[[Category: Oxygen storage-transport complex]]
[[Category: Rice]]