1nlw
From Proteopedia
Crystal structure of Mad-Max recognizing DNA
Structural highlights
FunctionMAD1_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. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedX-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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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