==COCRYSTAL STRUCTURE OF RFX-DBD IN COMPLEX WITH ITS COGNATE X-BOX BINDING SITE==

<StructureSection load='1dp7' size='340' side='right'caption='[[1dp7]], [[Resolution|resolution]] 1.50&Aring;' scene=''>

<table><tr><td colspan='2'>[[1dp7]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DP7 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1DP7 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1dp7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1dp7 OCA], [http://pdbe.org/1dp7 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1dp7 RCSB], [http://www.ebi.ac.uk/pdbsum/1dp7 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1dp7 ProSAT]</span></td></tr>

== Function ==

[[http://www.uniprot.org/uniprot/RFX1_HUMAN RFX1_HUMAN]] Regulatory factor essential for MHC class II genes expression. Binds to the X boxes of MHC class II genes. Also binds to an inverted repeat (ENH1) required for hepatitis B virus genes expression and to the most upstream element (alpha) of the RPL30 promoter.

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== Publication Abstract from PubMed ==

Regulatory factor X (RFX) proteins are transcriptional activators that recognize X-boxes (DNA of the sequence 5'-GTNRCC(0-3N)RGYAAC-3', where N is any nucleotide, R is a purine and Y is a pyrimidine) using a highly conserved 76-residue DNA-binding domain (DBD). DNA-binding defects in the protein RFX5 cause bare lymphocyte syndrome or major histocompatibility antigen class II deficiency. RFX1, -2 and -3 regulate expression of other medically important gene products (for example, interleukin-5 receptor alpha chain, IL-5R alpha). Fusions of the ligand-binding domain of the oestrogen receptor with the DBD of RFX4 occur in some human breast tumours. Here we present a 1.5 A-resolution structure of two copies of the DBD of human RFX1 (hRFX1) binding cooperatively to a symmetrical X-box. hRFX1 is an unusual member of the winged-helix subfamily of helix-turn-helix proteins because it uses a beta-hairpin (or wing) to recognize DNA instead of the recognition helix typical of helix-turn-helix proteins. A new model for interactions between linker histones and DNA is proposed.

Structure of the winged-helix protein hRFX1 reveals a new mode of DNA binding.,Gajiwala KS, Chen H, Cornille F, Roques BP, Reith W, Mach B, Burley SK Nature. 2000 Feb 24;403(6772):916-21. PMID:10706293<ref>PMID:10706293</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 1dp7" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Burley, S K]]

[[Category: Protein-dna cocrystal structure]]

[[Category: Winged helix]]