1M7W image
Entry Detail
PDB ID:
1M7W
Title:
HNF4a ligand binding domain with bound fatty acid
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2002-07-22
Release Date:
2003-07-01
Method Details:
Experimental Method:
Resolution:
2.80 Å
R-Value Free:
0.28
R-Value Work:
0.23
Space Group:
P 41 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Hepatocyte nuclear factor 4-alpha
Chain IDs:A, B, C, D
Chain Length:250
Number of Molecules:4
Biological Source:Rattus rattus
Ligand Molecules
Primary Citation
Crystal structure of the HNF4 alpha ligand binding domain in complex with endogenous fatty acid ligand
J.Biol.Chem. 277 37973 37976 (2002)
PMID: 12193589 DOI: 10.1074/jbc.C200420200

Abstact

HNF4 alpha is an orphan member of the nuclear receptor family with prominent functions in liver, gut, kidney and pancreatic beta cells. We have solved the x-ray crystal structure of the HNF4 alpha ligand binding domain, which adopts a canonical fold. Two conformational states are present within each homodimer: an open form with alpha helix 12 (alpha 12) extended and collinear with alpha 10 and a closed form with alpha 12 folded against the body of the domain. Although the protein was crystallized without added ligands, the ligand binding pockets of both closed and open forms contain fatty acids. The carboxylic acid headgroup of the fatty acid ion pairs with the guanidinium group of Arg(226) at one end of the ligand binding pocket, while the aliphatic chain fills a long, narrow channel that is lined with hydrophobic residues. These findings suggest that fatty acids are endogenous ligands for HNF4 alpha and establish a framework for understanding how HNF4 alpha activity is enhanced by ligand binding and diminished by MODY1 mutations.

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Primary Citation of related structures