View source for 7atg


==Crystal structure of Z-DNA in complex with putrescinium and potassium cations at ultrahigh-resolution==
<StructureSection load='7atg' size='340' side='right'caption='[[7atg]], [[Resolution|resolution]] 0.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7atg]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7ATG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7ATG 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]] 0.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=58I:4-azaniumylbutylazanium'>58I</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</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=7atg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7atg OCA], [https://pdbe.org/7atg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7atg RCSB], [https://www.ebi.ac.uk/pdbsum/7atg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7atg ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The X-ray crystal structure of the d(CGCGCG)2/putrescine(2+)/K(+) complex has been determined at 0.60 A resolution. Stereochemical restraints were used only for the putrescinium dication, and 23 bonds and 18 angles of the Z-DNA nucleotides with dual conformation. The N atoms of the putrescine(2+) dication form three direct hydrogen bonds with the N7_G atoms of three different Z-DNA molecules, plus three water-mediated hydrogen bonds with cytosine, guanine and phosphate acceptors. A unique potassium cation was also unambiguously identified in the structure, albeit at a approximately 0.5 occupation site shared with a water molecule, providing the first example of such a complex with Z-DNA. The K(+) cation has coordination number of eight and an irregular coordination sphere, formed by four water molecules and four O atoms from two phosphate groups of the Z-DNA, including ligands present at fractional occupancy. The structural disorder of the Z-DNA duplex is manifested by the presence of alternate conformations along the DNA backbone. Comparison of the position and interactions of putrescine(2+) in the present structure with other ultra-high-resolution structures of Z-DNA in complexes with Mn(2+) and Zn(2+) ions shows that the dicationic putrescinium moiety can effectively substitute these metal ions for stabilization of Z-type DNA duplexes. Furthermore, this comparison also suggests that the spermine(4+) tetracation has a higher affinity for Z-DNA than K(+).

Crystal structure of Z-DNA in complex with the polyamine putrescine and potassium cations at ultra-high resolution.,Drozdzal P, Gilski M, Jaskolski M Acta Crystallogr B Struct Sci Cryst Eng Mater. 2021 Jun 1;77(Pt 3):331-338. doi: , 10.1107/S2052520621002663. Epub 2021 May 6. PMID:34096514<ref>PMID:34096514</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7atg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Drozdzal P]]
[[Category: Gilski M]]
[[Category: Jaskolski M]]