View source for 6cnq


==MBD2 in complex with methylated DNA==
<StructureSection load='6cnq' size='340' side='right'caption='[[6cnq]], [[Resolution|resolution]] 2.15&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6cnq]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=6c2e 6c2e]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6CNQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6CNQ 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]] 2.151&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=5CM:5-METHYL-2-DEOXY-CYTIDINE-5-MONOPHOSPHATE'>5CM</scene>, <scene name='pdbligand=UNX:UNKNOWN+ATOM+OR+ION'>UNX</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=6cnq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6cnq OCA], [https://pdbe.org/6cnq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6cnq RCSB], [https://www.ebi.ac.uk/pdbsum/6cnq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6cnq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MBD2_HUMAN MBD2_HUMAN] Binds CpG islands in promoters where the DNA is methylated at position 5 of cytosine within CpG dinucleotides. Binds hemimethylated DNA as well. Recruits histone deacetylases and DNA methyltransferases. Acts as transcriptional repressor and plays a role in gene silencing. Functions as a scaffold protein, targeting GATAD2A and GATAD2B to chromatin to promote repression. May enhance the activation of some unmethylated cAMP-responsive promoters.<ref>PMID:10471499</ref> <ref>PMID:10947852</ref> <ref>PMID:12665568</ref> <ref>PMID:16415179</ref> <ref>PMID:24307175</ref> <ref>PMID:9774669</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cytosine methylation is a well characterized epigenetic mark and occurs at both CG and non-CG sites in DNA. Both methylated CG (mCG)- and mCH (H = A, C, or T)-containing DNAs, especially mCAC-containing DNAs, are recognized by methyl-CpG-binding protein 2 (MeCP2) to regulate gene expression in neuron development. However, the molecular mechanism involved in the binding of methyl-CpG-binding domain (MBD) of MeCP2 to these different DNA motifs is unclear. Here, we systematically characterized the DNA-binding selectivity of the MBDs in MeCP2 and MBD1-4 with isothermal titration calorimetry-based binding assays, mutagenesis studies, and X-ray crystallography. We found that the MBD domains of MeCP2 and MBD1-4&lt;br /&gt;bind mCG-containing DNAs independently of the sequence outside the mCG dinucleotide. Moreover, some 1 MBDs bound to both methylated and unmethylated CA dinucleotide-&lt;br /&gt;containing DNAs, with a preference for the CAC sequence motif. We also found that MBD domains bind to mCA or nonmethylated CA DNA by recognizing the complementary TG dinucleotide, which is consistent with an overlooked ligand of MeCP2, i.e., the matrix/scaffold attachment regions (MARs/SARs) with a consensus sequence of 5'-GGTGT-3', which was&lt;br /&gt;identified in early 1990s. Our results also explain why MeCP2 exhibits similar binding affinity to both mCAand hmCA-containing dsDNAs. In summary, our results suggest that in addition to mCG sites, unmethylated CA or TG sites also serve as DNA-binding sites for MeCP2 and other MBDcontaining proteins. This discovery expands the genome-wide activity of MBD-containing proteins in gene regulation.

Structural basis for the ability of MBD domains to bind methyl-CG and TG sites in DNA.,Liu K, Xu C, Lei M, Yang A, Loppnau P, Hughes TR, Min J J Biol Chem. 2018 Mar 22. pii: RA118.001785. doi: 10.1074/jbc.RA118.001785. PMID:29567833<ref>PMID:29567833</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6cnq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Methyl CpG binding protein 3D structures|Methyl CpG binding protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Liu K]]
[[Category: Min J]]
[[Category: Xu C]]