View source for 7d69


==Cryo-EM structure of the nucleosome containing Giardia histones==
<StructureSection load='7d69' size='340' side='right'caption='[[7d69]], [[Resolution|resolution]] 3.57&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7d69]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Giardia_intestinalis Giardia intestinalis] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7D69 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7D69 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.57&#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=7d69 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7d69 OCA], [https://pdbe.org/7d69 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7d69 RCSB], [https://www.ebi.ac.uk/pdbsum/7d69 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7d69 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/E2RU29_GIAIC E2RU29_GIAIC] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Giardia lamblia is a pathogenic unicellular eukaryotic parasite that causes giardiasis. Its genome encodes the canonical histones H2A, H2B, H3, and H4, which share low amino acid sequence identity with their human orthologues. We determined the structure of the G. lamblia nucleosome core particle (NCP) at 3.6 A resolution by cryo-electron microscopy. G. lamblia histones form a characteristic NCP, in which the visible 125 base-pair region of the DNA is wrapped in a left-handed supercoil. The acidic patch on the G. lamblia octamer is deeper, due to an insertion extending the H2B alpha1 helix and L1 loop, and thus cannot bind the LANA acidic patch binding peptide. The DNA and histone regions near the DNA entry-exit sites could not be assigned, suggesting that these regions are asymmetrically flexible in the G. lamblia NCP. Characterization by thermal unfolding in solution revealed that both the H2A-H2B and DNA association with the G. lamblia H3-H4 were weaker than those for human H3-H4. These results demonstrate the uniformity of the histone octamer as the organizing platform for eukaryotic chromatin, but also illustrate the unrecognized capability for large scale sequence variations that enable the adaptability of histone octamer surfaces and confer internal stability.

Cryo-EM structure of the nucleosome core particle containing Giardia lamblia histones.,Sato S, Takizawa Y, Hoshikawa F, Dacher M, Tanaka H, Tachiwana H, Kujirai T, Iikura Y, Ho CH, Adachi N, Patwal I, Flaus A, Kurumizaka H Nucleic Acids Res. 2021 Sep 7;49(15):8934-8946. doi: 10.1093/nar/gkab644. PMID:34352093<ref>PMID:34352093</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7d69" style="background-color:#fffaf0;"></div>

==See Also==
*[[Histone 3D structures|Histone 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Giardia intestinalis]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Kurumizaka H]]
[[Category: Sato S]]
[[Category: Takizawa Y]]