View source for 9cb5


==Crystal structure of nucleolin in complex with MYC promoter G-quadruplex==
<StructureSection load='9cb5' size='340' side='right'caption='[[9cb5]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9cb5]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9CB5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9CB5 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]] 2.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=9cb5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9cb5 OCA], [https://pdbe.org/9cb5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9cb5 RCSB], [https://www.ebi.ac.uk/pdbsum/9cb5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9cb5 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NUCL_HUMAN NUCL_HUMAN] Nucleolin is the major nucleolar protein of growing eukaryotic cells. It is found associated with intranucleolar chromatin and pre-ribosomal particles. It induces chromatin decondensation by binding to histone H1. It is thought to play a role in pre-rRNA transcription and ribosome assembly. May play a role in the process of transcriptional elongation. Binds RNA oligonucleotides with 5'-UUAGGG-3' repeats more tightly than the telomeric single-stranded DNA 5'-TTAGGG-3' repeats.<ref>PMID:10393184</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The MYC oncogene promoter G-quadruplex (MycG4) regulates transcription and is a prevalent G4 locus in immortal cells. Nucleolin, a major MycG4-binding protein, exhibits greater affinity for MycG4 than for nucleolin recognition element (NRE) RNA. Nucleolin's four RNA binding domains (RBDs) are essential for high-affinity MycG4 binding. We present the 2.6-angstrom crystal structure of the nucleolin-MycG4 complex, revealing a folded parallel three-tetrad G-quadruplex with two coordinating potassium ions (K(+)), interacting with RBD1, RBD2, and Linker12 through its 6-nucleotide (nt) central loop and 5' flanking region. RBD3 and RBD4 bind MycG4's 1-nt loops as demonstrated by nuclear magnetic resonance (NMR). Cleavage under targets and tagmentation sequencing confirmed nucleolin's binding to MycG4 in cells. Our results revealed a G4 conformation-based recognition by a regulating protein through multivalent interactions, suggesting that G4s are nucleolin's primary cellular substrates, indicating G4 epigenetic transcriptional regulation and helping G4-targeted drug discovery.

Structural basis for nucleolin recognition of MYC promoter G-quadruplex.,Chen L, Dickerhoff J, Zheng KW, Erramilli S, Feng H, Wu G, Onel B, Chen Y, Wang KB, Carver M, Lin C, Sakai S, Wan J, Vinson C, Hurley L, Kossiakoff AA, Deng N, Bai Y, Noinaj N, Yang D Science. 2025 Apr 18;388(6744):eadr1752. doi: 10.1126/science.adr1752. Epub 2025 , Apr 18. PMID:40245140<ref>PMID:40245140</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 9cb5" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Chen L]]
[[Category: Dickerhoff J]]
[[Category: Noinaj N]]
[[Category: Yang D]]