View source for 6pxz


==Crystal Structure of mouse Serum Amyloid A3 (SAA3) in the trimeric form==
<StructureSection load='6pxz' size='340' side='right'caption='[[6pxz]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6pxz]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6PXZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6PXZ 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DMU:DECYL-BETA-D-MALTOPYRANOSIDE'>DMU</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=6pxz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6pxz OCA], [https://pdbe.org/6pxz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6pxz RCSB], [https://www.ebi.ac.uk/pdbsum/6pxz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6pxz ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SAA3_MOUSE SAA3_MOUSE] Major acute phase reactant. Apolipoprotein of the HDL complex.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Serum amyloid A (SAA) proteins are strongly induced in the liver by systemic infection and in the intestine by bacterial colonization. In infected mice, SAA proteins circulate in association with the vitamin A derivative retinol, suggesting that SAAs transport retinol during infection. Here we illuminate a structural basis for the retinol-SAA interaction. In the bloodstream of infected mice, most SAA is complexed with high-density lipoprotein (HDL). However, we found that the majority of the circulating retinol was associated with the small fraction of SAA proteins that circulate without binding to HDL, thus identifying free SAA as the predominant retinol-binding form in vivo. We then determined the crystal structure of retinol-bound mouse SAA3 at a resolution of 2.2 A. Retinol-bound SAA3 formed a novel asymmetric trimeric assembly that was generated by the hydrophobic packing of the conserved amphipathic helices alpha1 and alpha3. This hydrophobic packing created a retinol-binding pocket in the center of the trimer, which was confirmed by mutagenesis studies. Together, these findings illuminate the molecular basis for retinol transport by SAA proteins during infection.

Molecular basis for retinol binding by serum amyloid A during infection.,Hu Z, Bang YJ, Ruhn KA, Hooper LV Proc Natl Acad Sci U S A. 2019 Sep 17;116(38):19077-19082. doi: , 10.1073/pnas.1910713116. Epub 2019 Sep 4. PMID:31484771<ref>PMID:31484771</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6pxz" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Hooper LV]]
[[Category: Hu Z]]