==Crystal structure of Mad-Max recognizing DNA==

<StructureSection load='1nlw' size='340' side='right'caption='[[1nlw]], [[Resolution|resolution]] 2.00&Aring;' scene=''>

<table><tr><td colspan='2'>[[1nlw]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NLW OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1NLW FirstGlance]. <br>

</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1nkp|1nkp]]</div></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1nlw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nlw OCA], [http://pdbe.org/1nlw PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1nlw RCSB], [http://www.ebi.ac.uk/pdbsum/1nlw PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1nlw ProSAT]</span></td></tr>

== Function ==

[[http://www.uniprot.org/uniprot/MAX_HUMAN MAX_HUMAN]] Transcription regulator. Forms a sequence-specific DNA-binding protein complex with MYC or MAD which recognizes the core sequence 5'-CAC[GA]TG-3'. The MYC-MAX complex is a transcriptional activator, whereas the MAD-MAX complex is a repressor. May repress transcription via the recruitment of a chromatin remodeling complex containing H3 'Lys-9' histone methyltransferase activity. [[http://www.uniprot.org/uniprot/MAD1_HUMAN MAD1_HUMAN]] Transcriptional repressor. MAD binds with MAX to form a sequence-specific DNA-binding protein complex which recognizes the core sequence 5'-CAC[GA]TG-3'. MAD thus antagonizes MYC transcriptional activity by competing for MAX.

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== Publication Abstract from PubMed ==

X-ray structures of the basic/helix-loop-helix/leucine zipper (bHLHZ) domains of Myc-Max and Mad-Max heterodimers bound to their common DNA target (Enhancer or E box hexanucleotide, 5'-CACGTG-3') have been determined at 1.9 A and 2.0 A resolution, respectively. E box recognition by these two structurally similar transcription factor pairs determines whether a cell will divide and proliferate (Myc-Max) or differentiate and become quiescent (Mad-Max). Deregulation of Myc has been implicated in the development of many human cancers, including Burkitt's lymphoma, neuroblastomas, and small cell lung cancers. Both quasisymmetric heterodimers resemble the symmetric Max homodimer, albeit with marked structural differences in the coiled-coil leucine zipper regions that explain preferential homo- and heteromeric dimerization of these three evolutionarily related DNA-binding proteins. The Myc-Max heterodimer, but not its Mad-Max counterpart, dimerizes to form a bivalent heterotetramer, which explains how Myc can upregulate expression of genes with promoters bearing widely separated E boxes.

X-ray structures of Myc-Max and Mad-Max recognizing DNA. Molecular bases of regulation by proto-oncogenic transcription factors.,Nair SK, Burley SK Cell. 2003 Jan 24;112(2):193-205. PMID:12553908<ref>PMID:12553908</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 1nlw" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Human]]

[[Category: Burley, S K]]

[[Category: Transcription-dna complex]]