View source for 1vb5


==Crystal Structure Analysis of the Pyrococcus horikoshii OT3 translation initiation factor eIF-2B==
<StructureSection load='1vb5' size='340' side='right'caption='[[1vb5]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1vb5]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_horikoshii_OT3 Pyrococcus horikoshii OT3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VB5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1VB5 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]] 2.2&#8491;</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=1vb5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1vb5 OCA], [https://pdbe.org/1vb5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1vb5 RCSB], [https://www.ebi.ac.uk/pdbsum/1vb5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1vb5 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/EI2BL_PYRHO EI2BL_PYRHO] Catalyzes the exchange of initiation factor 2-bound GDP for GTP.
== 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/vb/1vb5_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=1vb5 ConSurf].
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== Publication Abstract from PubMed ==
Eukaryotic translation initiation factor 2B (eIF2B) is the guanine-nucleotide exchange factor for eukaryotic initiation factor 2 (eIF2). eIF2B is a heteropentameric protein composed of alpha- subunits. The alpha, beta, and delta subunits form a regulatory subcomplex, while the gamma and form a catalytic subcomplex. Archaea possess homologues of alpha, beta, and delta subunits of eIF2B. Here, we report the three-dimensional structure of an archaeal regulatory subunit (aIF2Balpha) from the hyperthermophilic archaeon Pyrococcus horikoshii OT3 determined by X-ray crystallography at 2.2A resolution. aIF2Balpha consists of two subdomains, an N-domain (residues 1-95) and a C-domain (residues 96-276), connected by a long alpha-helix (alpha5: 78-106). The N-domain contains a five helix bundle structure, while the C-domain folds into the alpha/beta structure, thus showing similarity to D-ribose-5-phosphate isomerase structure. The presence of two molecules in the crystallographic asymmetric unit and the gel filtration analysis suggest a dimeric structure of aIF2Balpha in solution, interacting with each other by C-domains. Furthermore, the crystallographic 3-fold symmetry generates a homohexameric structure of aIF2Balpha; the interaction is primarily mediated by the long alpha-helix at the N-domains. This structure suggests an architecture of the three subunits, alpha, beta, and delta, in the regulatory subcomplex within eIF2B.

Crystal structure of the regulatory subunit of archaeal initiation factor 2B (aIF2B) from hyperthermophilic archaeon Pyrococcus horikoshii OT3: a proposed structure of the regulatory subcomplex of eukaryotic IF2B.,Kakuta Y, Tahara M, Maetani S, Yao M, Tanaka I, Kimura M Biochem Biophys Res Commun. 2004 Jul 2;319(3):725-32. PMID:15184043<ref>PMID:15184043</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pyrococcus horikoshii OT3]]
[[Category: Kakuta Y]]
[[Category: Kimura M]]
[[Category: Maetani S]]
[[Category: Tahara M]]