1g2z
DIMERIZATION DOMAIN OF HNF-1ALPHA WITH A LEU 13 SELENOMETHIONINE SUBSTITUTIONDIMERIZATION DOMAIN OF HNF-1ALPHA WITH A LEU 13 SELENOMETHIONINE SUBSTITUTION
Structural highlights
FunctionHNF1A_MOUSE Transcriptional activator that regulates the tissue specific expression of multiple genes, especially in pancreatic islet cells and in liver. Required for the expression of several liver specific genes. Binds to the inverted palindrome 5'-GTTAATNATTAAC-3'.[1] [2] Publication Abstract from PubMedThe N-terminal dimerization domain of the transcriptional activator hepatocyte nuclear factor-1alpha (HNF-1alpha) is essential for DNA binding and association of the transcriptional coactivator, DCoH (dimerization cofactor of HNF-1). To investigate the basis for dimerization of HNF-1 proteins, we determined the 1.2 A resolution X-ray crystal structure of the dimerization domain of HNF-1alpha (HNF-p1). Phasing was facilitated by devising a simple synthesis for Fmoc-selenomethionine and substituting leucine residues with selenomethionine. The HNF-1 dimerization domain forms a unique, four-helix bundle that is preserved with localized conformational shifts in the DCoH complex. In three different crystal forms, HNF-p1 displays subtle shifts in the conformation of the interhelix loop and the crossing angle between the amino- and carboxyl-terminal helices. In all three crystal forms, the HNF-p1 dimers pair through an exposed hydrophobic surface that also forms the binding site for DCoH. Conserved core residues in the dimerization domain of the homologous transcriptional regulator HNF-1beta rationalize the functional heterodimerization of the HNF-1alpha and HNF-1beta proteins. Mutations in HNF-1alpha are associated with maturity-onset diabetes of the young type 3 (MODY3), and the structure of HNF-p1 provides insights into the effects of three MODY3 mutations. High-resolution structure of the HNF-1alpha dimerization domain.,Rose RB, Endrizzi JA, Cronk JD, Holton J, Alber T Biochemistry. 2000 Dec 12;39(49):15062-70. PMID:11106484[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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