View source for 2vhb


==AZIDE ADDUCT OF THE BACTERIAL HEMOGLOBIN FROM VITREOSCILLA STERCORARIA==
<StructureSection load='2vhb' size='340' side='right'caption='[[2vhb]], [[Resolution|resolution]] 1.76&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2vhb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Vitreoscilla_stercoraria Vitreoscilla stercoraria]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VHB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2VHB 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]] 1.76&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AZI:AZIDE+ION'>AZI</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</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=2vhb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vhb OCA], [https://pdbe.org/2vhb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2vhb RCSB], [https://www.ebi.ac.uk/pdbsum/2vhb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2vhb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BAHG_VITST BAHG_VITST] This protein functions as a terminal oxidase.
== 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/vh/2vhb_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=2vhb ConSurf].
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== Publication Abstract from PubMed ==
BACKGROUND: The first hemoglobin identified in bacteria was isolated from Vitreoscilla stercoraria (VtHb) as a homodimeric species. The wild-type protein has been reported to display medium oxygen affinity and cooperative ligand-binding properties. Moreover, VtHb can support aerobic growth in Escherichia coli with impaired terminal oxidase function. This ability of VtHb to improve the growth properties of E. coli has important applications in fermentation technology, assisting the overexpression of recombinant proteins and antibiotics. Oxygen binding heme domains have been identified in chimeric proteins from bacteria and yeast, where they are covalently linked to FAD- and NAD(P)H-binding domains. We investigate here the fold, the distal heme site structure and the quaternary assembly of a bacterial hemoglobin which does not bear the typical flavohemoglobin domain organization. RESULTS: The VtHb three-dimensional structure conforms to the well known globin fold. Nevertheless, the polypeptide segment connecting helices C and E is disordered, and residues E7-E10 (defined according to the standard globin fold nomenclature) do not adopt the usual alpha-helical conformation, thus locating Gln53(E7) out of the heme pocket. Binding of azide to the heme iron introduces substantial structural perturbations in the heme distal site residues, particularly Tyr29(B10) and Pro54(E8). The quaternary assembly of homodimeric VtHb, not observed before within the globin family, is based on a molecular interface defined by helices F and H of both subunits, the two heme iron atoms being 34 A apart. CONCLUSIONS: The unusual heme distal site structure observed shows that previously undescribed molecular mechanisms of ligand stabilization are operative in VtHb. The polypeptide chain disorder observed in the CE region indicates a potential site of interaction with the FAD/NADH reductase partner, in analogy with observations in the chimeric flavohemoglobin from Alcaligenes eutrophus.

Unusual structure of the oxygen-binding site in the dimeric bacterial hemoglobin from Vitreoscilla sp.,Tarricone C, Galizzi A, Coda A, Ascenzi P, Bolognesi M Structure. 1997 Apr 15;5(4):497-507. PMID:9115439<ref>PMID:9115439</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 2vhb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemoglobin 3D structures|Hemoglobin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Vitreoscilla stercoraria]]
[[Category: Ascenzi P]]
[[Category: Bolognesi M]]
[[Category: Coda A]]
[[Category: Galizzi A]]
[[Category: Tarricone C]]