View source for 5wwc


==The crystal structure of Cren7 mutant L28M in complex with dsDNA==
<StructureSection load='5wwc' size='340' side='right'caption='[[5wwc]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5wwc]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharolobus_solfataricus_P2 Saccharolobus solfataricus P2] 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=5WWC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5WWC 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]] 1.9&#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=5wwc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5wwc OCA], [https://pdbe.org/5wwc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5wwc RCSB], [https://www.ebi.ac.uk/pdbsum/5wwc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5wwc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CREN7_SACS2 CREN7_SACS2] A highly abundant probable chromatin protein, it binds double-strand DNA without sequence specificity; there is approximately 1 Cren7 molecule for 12 bp of DNA. Constrains negative DNA supercoils, increases DNA stability against thermal denaturation. Binding does not require protein methylation. Binds single-strand DNA weakly.<ref>PMID:18096617</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Crenarchaeal chromatin protein Cren7 binds double-stranded DNA in the minor groove, introducing a sharp single-step DNA kink. The side chain of Leu28, a residue conserved among all Cren7 homologues, intercalates into the kink DNA step. In this study, we replaced Leu28 with a residue containing a hydrophobic side chain of different sizes (i.e., L28A, L28V, L28I, L28M and L28F). Both the stability of the Cren7-DNA complex and the ability of Cren7 to constrain DNA supercoils correlated well with the size of the intercalated side chain. Structural analysis shows that L28A induces a kink (~43o), nearly as sharp as that produced by wild-type Cren7 (~48o), in the bound DNA despite the lack of side chain intercalation. L28F inserts a large hydrophobic side chain deep into the DNA step, but introduces a smaller kink (~39o) than that formed by the wild-type protein (~50o). Mutation of Leu28 into methionine yields two protein conformers differing in loop beta3-beta4 orientation as well as DNA binding surface and DNA geometry in the protein-DNA structure. Our results indicate that side chain intercalation is not directly responsible for DNA kinking or bending by Cren7, but plays a critical role in the stabilization of the Cren7-DNA complex. In addition, the flexibility of loop beta3-beta4 in Cren7, as revealed in the crystal structure of L28M-DNA, may serve a role in the modulation of chromosomal organization and function in the cell.

Roles of Leu28 side chain intercalation in the interaction between Cren7 and DNA.,Zhang Z, Zhao M, Wang L, Chen Y, Dong Y, Gong Y, Huang L Biochem J. 2017 Apr 4. pii: BCJ20170036. doi: 10.1042/BCJ20170036. PMID:28377493<ref>PMID:28377493</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5wwc" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharolobus solfataricus P2]]
[[Category: Synthetic construct]]
[[Category: Chen YY]]
[[Category: Dong YH]]
[[Category: Gong Y]]
[[Category: Huang L]]
[[Category: Wang L]]
[[Category: Zhang ZF]]
[[Category: Zhao MH]]