View source for 6tem


==CENP-A nucleosome core particle with 145 base pairs of the Widom 601 sequence by cryo-EM==
<StructureSection load='6tem' size='340' side='right'caption='[[6tem]], [[Resolution|resolution]] 3.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6tem]] is a 10 chain structure with sequence from [http://en.wikipedia.org/wiki/ ], [http://en.wikipedia.org/wiki/African_clawed_frog African clawed frog] and [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6TEM OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6TEM FirstGlance]. <br>
</td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CENPA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), hist1h2aj, LOC494591 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=8355 African clawed frog])</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6tem FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6tem OCA], [http://pdbe.org/6tem PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6tem RCSB], [http://www.ebi.ac.uk/pdbsum/6tem PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6tem ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/H2B11_XENLA H2B11_XENLA]] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. [[http://www.uniprot.org/uniprot/CENPA_HUMAN CENPA_HUMAN]] Histone H3-like variant which exclusively replaces conventional H3 in the nucleosome core of centromeric chromatin at the inner plate of the kinetochore. Required for recruitment and assembly of kinetochore proteins, mitotic progression and chromosome segregation. May serve as an epigenetic mark that propagates centromere identity through replication and cell division. The CENPA-H4 heterotetramer can bind DNA by itself (in vitro).<ref>PMID:20739937</ref> <ref>PMID:21478274</ref>  [[http://www.uniprot.org/uniprot/H4_XENLA H4_XENLA]] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. 
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== Publication Abstract from PubMed ==
The histone H3 variant CENP-A marks centromeres epigenetically and is essential for mitotic fidelity. Previous crystallographic studies of the CENP-A nucleosome core particle (NCP) reconstituted with a human alpha-satellite DNA derivative revealed both DNA ends to be highly flexible, a feature important for CENP-A mitotic functions. However, recent cryo-EM studies of CENP-A NCP complexes comprising primarily Widom 601 DNA reported well-ordered DNA ends. Here, we report the cryo-EM structure of the CENP-A 601 NCP determined by Volta phase-plate imaging. The data reveal that one ('left') 601 DNA end is well ordered whereas the other ('right') end is flexible and partly detached from the histone core, suggesting sequence-dependent dynamics of the DNA termini. Indeed, a molecular dynamics simulation of the CENP-A 601 NCP confirmed the distinct dynamics of the two DNA extremities. Reprocessing the image data using two-fold symmetry yielded a cryo-EM map in which both DNA ends appeared well ordered, indicating that such an artefact may inadvertently arise if NCP asymmetry is lost during image processing. These findings enhance our understanding of the dynamic features that discriminate CENP-A from H3 nucleosomes by revealing that DNA end flexibility can be fine-tuned in a sequence-dependent manner.

Phase-plate cryo-EM structure of the Widom 601 CENP-A nucleosome core particle reveals differential flexibility of the DNA ends.,Boopathi R, Danev R, Khoshouei M, Kale S, Nahata S, Ramos L, Angelov D, Dimitrov S, Hamiche A, Petosa C, Bednar J Nucleic Acids Res. 2020 Apr 20. pii: 5822962. doi: 10.1093/nar/gkaa246. PMID:32313946<ref>PMID:32313946</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 6tem" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: African clawed frog]]
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Bednar, J]]
[[Category: Boopathi, R]]
[[Category: Danev, R]]
[[Category: Petosa, C]]
[[Category: Cenp-a nucleosome]]
[[Category: Dna binding protein]]
[[Category: Protein-dna complex]]