View source for 4nk1


==Crystal structure of phosphate-bound Hell's gate globin IV==
<StructureSection load='4nk1' size='340' side='right'caption='[[4nk1]], [[Resolution|resolution]] 2.21&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4nk1]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Methylacidiphilum_infernorum_V4 Methylacidiphilum infernorum V4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4NK1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4NK1 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]] 2.21&#8491;</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>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</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=4nk1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4nk1 OCA], [https://pdbe.org/4nk1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4nk1 RCSB], [https://www.ebi.ac.uk/pdbsum/4nk1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4nk1 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B3DVC3_METI4 B3DVC3_METI4] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
A truncated haemoglobin (tHb) has been identified in an acidophilic and thermophilic methanotroph Methylacidiphilium infernorum. Hell's Gate Globin IV (HGbIV) and its related tHbs differ from all other bacterial tHbs due to their distinctively large sequence and polar distal haem pocket residues. Here we report the crystal structure of HGbIV determined at 1.96 A resolution. The HGbIV structure has the distinctive 2/2 alpha-helical structure with extensions at both termini. It has a large distal site cavity in the haem pocket surrounded by four polar residues: His70(B9), His71(B10), Ser97(E11) and Trp137(G8). This cavity can bind bulky ligands such as a phosphate ion. Conformational shifts of His71(B10), Leu90(E4) and Leu93(E7) can also provide more space to accommodate larger ligands than the phosphate ion. The entrance/exit of such bulky ligands might be facilitated by positional flexibility in the CD1 loop, E helix and haem-propionate A. Therefore, the large cavity in HGbIV with polar His70(B9) and His71(B10), in contrast to the distal sites of other bacterial tHbs surrounded by non-polar residues, suggests its distinct physiological functions.

Crystal structure of truncated haemoglobin from an extremely thermophilic and acidophilic bacterium.,Jamil F, Teh AH, Schadich E, Saito JA, Najimudin N, Alam M J Biochem. 2014 Aug;156(2):97-106. doi: 10.1093/jb/mvu023. Epub 2014 Apr 14. PMID:24733432<ref>PMID:24733432</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4nk1" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Methylacidiphilum infernorum V4]]
[[Category: Jamil F]]