Crystal structure of the HNF4 alpha ligand binding domain in complex with endogenous fatty acid ligand. J Biol Chem 2002 Oct 11;277(41):37973-6
Date
08/24/2002Pubmed ID
12193589DOI
10.1074/jbc.C200420200Scopus ID
2-s2.0-0037063997 (requires institutional sign-in at Scopus site) 248 CitationsAbstract
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.
Author List
Dhe-Paganon S, Duda K, Iwamoto M, Chi YI, Shoelson SEAuthor
Young-In Chi PhD Assistant Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBasic Helix-Loop-Helix Leucine Zipper Transcription Factors
Binding Sites
Crystallography, X-Ray
DNA-Binding Proteins
Dimerization
Fatty Acids
Hepatocyte Nuclear Factor 4
Humans
Ligands
Models, Molecular
Mutation
Phosphoproteins
Protein Structure, Secondary
Protein Structure, Tertiary
Rats
Receptors, Cytoplasmic and Nuclear
Transcription Factors
