View source for 7x97


==Crystal structure of actinomycin D-echinomycin-d(AGCCCGT/ACGGGCT) complex==
<StructureSection load='7x97' size='340' side='right'caption='[[7x97]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7x97]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces Streptomyces] 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=7X97 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7X97 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]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=DSN:D-SERINE'>DSN</scene>, <scene name='pdbligand=DVA:D-VALINE'>DVA</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MVA:N-METHYLVALINE'>MVA</scene>, <scene name='pdbligand=N2C:N,S-DIMETHYLCYSTEINE'>N2C</scene>, <scene name='pdbligand=NCY:N-METHYLCYSTEINE'>NCY</scene>, <scene name='pdbligand=PXZ:2-AMINO-1,9-DICARBONYL-4,6-DIMETHYL-10-DEHYDRO-PHENOXAZIN-3-ONE'>PXZ</scene>, <scene name='pdbligand=QUI:2-CARBOXYQUINOXALINE'>QUI</scene>, <scene name='pdbligand=SAR:SARCOSINE'>SAR</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=7x97 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7x97 OCA], [https://pdbe.org/7x97 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7x97 RCSB], [https://www.ebi.ac.uk/pdbsum/7x97 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7x97 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The use of multiple drugs simultaneously targeting DNA is a promising strategy in cancer therapy for potentially overcoming single drug resistance. In support of this concept, we report that a combination of actinomycin D (ActD) and echinomycin (Echi), can interact in novel ways with native and mismatched DNA sequences, distinct from the structural effects produced by either drug alone. Changes in the former with GpC and CpG steps separated by a A:G or G:A mismatch or in a native DNA with canonical G:C and C:G base pairs, result in significant asymmetric backbone twists through staggered intercalation and base pair modulations. A wobble or Watson-Crick base pair at the two drug-binding interfaces can result in a single-stranded 'chair-shaped' DNA duplex with a straight helical axis. However, a novel sugar-edged hydrogen bonding geometry in the G:A mismatch leads to a 'curved-shaped' duplex. Two non-canonical G:C Hoogsteen base pairings produce a sharply kinked duplex in different forms and a four-way junction-like superstructure, respectively. Therefore, single base pair modulations on the two drug-binding interfaces could significantly affect global DNA structure. These structures thus provide a rationale for atypical DNA recognition via multiple DNA intercalators and a structural basis for the drugs' potential synergetic use.

Staggered intercalation of DNA duplexes with base-pair modulation by two distinct drug molecules induces asymmetric backbone twisting and structure polymorphism.,Satange R, Kao SH, Chien CM, Chou SH, Lin CC, Neidle S, Hou MH Nucleic Acids Res. 2022 Aug 26;50(15):8867-8881. doi: 10.1093/nar/gkac629. PMID:35871296<ref>PMID:35871296</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7x97" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces]]
[[Category: Synthetic construct]]
[[Category: Hou MH]]
[[Category: Kao SH]]
[[Category: Satange RB]]