View source for 2gj5


==Crystal structure of a secondary vitamin D3 binding site of milk beta-lactoglobulin==
<StructureSection load='2gj5' size='340' side='right'caption='[[2gj5]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2gj5]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GJ5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2GJ5 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=VD3:(1S,3Z)-3-[(2E)-2-[(1R,3AR,7AS)-7A-METHYL-1-[(2R)-6-METHYLHEPTAN-2-YL]-2,3,3A,5,6,7-HEXAHYDRO-1H-INDEN-4-YLIDENE]ETHYLIDENE]-4-METHYLIDENE-CYCLOHEXAN-1-OL'>VD3</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=2gj5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2gj5 OCA], [https://pdbe.org/2gj5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2gj5 RCSB], [https://www.ebi.ac.uk/pdbsum/2gj5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2gj5 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LACB_BOVIN LACB_BOVIN] Primary component of whey, it binds retinol and is probably involved in the transport of that molecule.
== 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/gj/2gj5_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=2gj5 ConSurf].
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== Publication Abstract from PubMed ==
Beta-lactoglobulin (beta-LG), one of the most investigated proteins, is a major bovine milk protein with a predominantly beta structure. The structural function of the only alpha-helix with three turns at the C-terminus is unknown. Vitamin D(3) binds to the central calyx formed by the beta-strands. Whether there are two vitamin D binding-sites in each beta-LG molecule has been a subject of controversy. Here, we report a second vitamin D(3) binding site identified by synchrotron X-ray diffraction (at 2.4 A resolution). In the central calyx binding mode, the aliphatic tail of vitamin D(3) clearly inserts into the binding cavity, where the 3-OH group of vitamin D(3) binds externally. The electron density map suggests that the 3-OH group interacts with the carbonyl of Lys-60 forming a hydrogen bond (2.97 A). The second binding site, however, is near the surface at the C-terminus (residues 136-149) containing part of an alpha-helix and a beta-strand I with 17.91 A in length, while the span of vitamin D(3) is about 12.51 A. A remarkable feature of the second exosite is that it combines an amphipathic alpha-helix providing nonpolar residues (Phe-136, Ala-139, and Leu-140) and a beta-strand providing a nonpolar (Ile-147) and a buried polar residue (Arg-148). They are linked by a hydrophobic loop (Ala-142, Leu-143, Pro-144, and Met-145). Thus, the binding pocket furnishes strong hydrophobic force to stabilize vitamin D(3) binding. This finding provides a new insight into the interaction between vitamin D(3) and beta-LG, in which the exosite may provide another route for the transport of vitamin D(3) in vitamin D(3) fortified dairy products. Atomic coordinates for the crystal structure of beta-LG-vitamin D(3) complex described in this work have been deposited in the PDB (access code 2GJ5).

Crystal structure of a secondary vitamin D3 binding site of milk beta-lactoglobulin.,Yang MC, Guan HH, Liu MY, Lin YH, Yang JM, Chen WL, Chen CJ, Mao SJ Proteins. 2008 May 15;71(3):1197-210. PMID:18004750<ref>PMID:18004750</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 2gj5" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-lactoglobulin 3D structures|Beta-lactoglobulin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Large Structures]]
[[Category: Chen CJ]]
[[Category: Chen WL]]
[[Category: Guan HH]]
[[Category: Liu MY]]
[[Category: Mao SJ]]
[[Category: Yang JM]]
[[Category: Yang MC]]