==STRUCTURE AND FUNCTION OF THE B/HLH/Z DOMAIN OF USF==

<StructureSection load='1an4' size='340' side='right'caption='[[1an4]], [[Resolution|resolution]] 2.90&Aring;' scene=''>

<table><tr><td colspan='2'>[[1an4]] is a 4 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=1AN4 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1AN4 FirstGlance]. <br>

</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=1an4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1an4 OCA], [http://pdbe.org/1an4 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1an4 RCSB], [http://www.ebi.ac.uk/pdbsum/1an4 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1an4 ProSAT]</span></td></tr>

== Disease ==

[[http://www.uniprot.org/uniprot/USF1_HUMAN USF1_HUMAN]] Genetic variations in USF1 are associated with hyperlipidemia combined type 1 (HYPLIP1) [MIM:[http://omim.org/entry/602491 602491]]; also known as familial combined hyperlipidemia type 1 (FCHL1). HYPLIP1 is characterized by elevated levels of serum total cholesterol, triglycerides or both, and is observed in about 20% of individuals with premature coronary heart disease.<ref>PMID:14991056</ref>

== Function ==

[[http://www.uniprot.org/uniprot/USF1_HUMAN USF1_HUMAN]] Transcription factor that binds to a symmetrical DNA sequence (E-boxes) (5'-CACGTG-3') that is found in a variety of viral and cellular promoters.

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== Publication Abstract from PubMed ==

The basic/helix-loop-helix/leucine zipper (b/HLH/Z) transcription factor upstream stimulatory factor (USF) and its isolated DNA binding domain undergo a random coil to alpha-helix folding transition on recognizing their cognate DNA. The USF b/HLH cocrystal structure resembles the structure of the b/HLH/Z domain of the homologous protein Max and reveals (i) that the truncated, b/HLH DNA binding domain homodimerizes, forming a parallel, left-handed four-helix bundle, and (ii) that the basic region becomes alpha-helical on binding to the major groove of the DNA sequence CACGTG. Hydrodynamic measurements show that the b/HLH/Z DNA binding domain of USF exists as a bivalent homotetramer. This tetramer forms at the USF physiological intranuclear concentration, and depends on the integrity of the leucine zipper motif. The ability to bind simultaneously to two independent sites suggests a role in DNA looping for the b/HLH/Z and Myc-related families of eukaryotic transcription factors.

Structure and function of the b/HLH/Z domain of USF.,Ferre-D'Amare AR, Pognonec P, Roeder RG, Burley SK EMBO J. 1994 Jan 1;13(1):180-9. PMID:8306960<ref>PMID:8306960</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 1an4" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Human]]

[[Category: Amare, A R.Ferre-D]]

[[Category: Transcription-dna complex]]