2GUT

Solution structure of the trans-activation domain of the human co-activator ARC105


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 20 
  • Conformers Submitted: 15 
  • Selection Criteria: lowest NOE target function with no NOE violations > 0.5 A, and angular violations > 5 deg 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

An ARC/Mediator subunit required for SREBP control of cholesterol and lipid homeostasis.

Yang, F.Vought, B.W.Satterlee, J.S.Walker, A.K.Jim Sun, Z.-Y.Watts, J.L.Debeaumont, R.Mako Saito, R.Hyberts, S.G.Yang, S.Macol, C.Iyer, L.Tjian, R.van den Heuvel, S.Hart, A.C.Wagner, G.Naar, A.M.

(2006) Nature 442: 700-704

  • DOI: https://doi.org/10.1038/nature04942
  • Primary Citation of Related Structures:  
    2GUT

  • PubMed Abstract: 

    The sterol regulatory element binding protein (SREBP) family of transcription activators are critical regulators of cholesterol and fatty acid homeostasis. We previously demonstrated that human SREBPs bind the CREB-binding protein (CBP)/p300 acetyltransferase KIX domain and recruit activator-recruited co-factor (ARC)/Mediator co-activator complexes through unknown mechanisms. Here we show that SREBPs use the evolutionarily conserved ARC105 (also called MED15) subunit to activate target genes. Structural analysis of the SREBP-binding domain in ARC105 by NMR revealed a three-helix bundle with marked similarity to the CBP/p300 KIX domain. In contrast to SREBPs, the CREB and c-Myb activators do not bind the ARC105 KIX domain, although they interact with the CBP KIX domain, revealing a surprising specificity among structurally related activator-binding domains. The Caenorhabditis elegans SREBP homologue SBP-1 promotes fatty acid homeostasis by regulating the expression of lipogenic enzymes. We found that, like SBP-1, the C. elegans ARC105 homologue MDT-15 is required for fatty acid homeostasis, and show that both SBP-1 and MDT-15 control transcription of genes governing desaturation of stearic acid to oleic acid. Notably, dietary addition of oleic acid significantly rescued various defects of nematodes targeted with RNA interference against sbp-1 and mdt-15, including impaired intestinal fat storage, infertility, decreased size and slow locomotion, suggesting that regulation of oleic acid levels represents a physiologically critical function of SBP-1 and MDT-15. Taken together, our findings demonstrate that ARC105 is a key effector of SREBP-dependent gene regulation and control of lipid homeostasis in metazoans.


  • Organizational Affiliation

    Massachusetts General Hospital Cancer Center, Building 149, 13th Street, Charlestown, Massachusetts 02129, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ARC/MEDIATOR, Positive cofactor 2 glutamine/Q-rich-associated protein77Homo sapiensMutation(s): 0 
Gene Names: PCQAPARC105CTG7ATIG1
UniProt & NIH Common Fund Data Resources
Find proteins for Q96RN5 (Homo sapiens)
Explore Q96RN5 
Go to UniProtKB:  Q96RN5
PHAROS:  Q96RN5
GTEx:  ENSG00000099917 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ96RN5
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 20 
  • Conformers Submitted: 15 
  • Selection Criteria: lowest NOE target function with no NOE violations > 0.5 A, and angular violations > 5 deg 

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-08-08
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-03-09
    Changes: Data collection, Database references, Derived calculations
  • Version 1.4: 2024-05-29
    Changes: Data collection