DNA-binding properties and secondary structural model of the hepatocyte nuclear factor 3/fork head domain.
An 84-amino acid segment of QRF-1 [glutamine (Q)-rich factor 1], a newly cloned, B-cell-derived DNA-binding protein, shows significant sequence homology with the DNA-binding domains of the hepatocyte nuclear factor 3/fork head family of proteins. Here we demonstrate that this 84-amino acid domain is necessary and sufficient for DNA binding. We also propose a secondary structural model for the domain. At the N-terminal portion of the model, a basic hook structure is followed by two amphipathic helices separated by a turn. Invariant amino acid residues within the two proposed helices form the hydrophobic cores. An aromatic kink and a third amphipathic helix comprise the center of the domain. At the C terminus, two variable-length loops flank a putative 7-amino acid helix followed by a short basic region.
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Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000378:metabolism; D003001:Cloning, Molecular; D016384:Consensus Sequence; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D004330:Drosophila / Q000378:metabolism; D051541:Hepatocyte Nuclear Factor 3-alpha; D051542:Hepatocyte Nuclear Factor 3-beta; D051543:Hepatocyte Nuclear Factor 3-gamma; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000378:metabolism; D016133:Polymerase Chain Reaction; D017433:Protein Structure, Secondary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism; D014981:Xenopus
D004268:DNA-Binding Proteins; C496499:FOXA1 protein, human; C496502:FOXA2 protein, human; C496505:FOXA3 protein, human; C496500:Foxa1 protein, mouse; C496501:Foxa1 protein, rat; C496503:Foxa2 protein, mouse; C496504:Foxa2 protein, rat; C496506:Foxa3 protein, mouse; C496507:Foxa3 protein, rat; D051541:Hepatocyte Nuclear Factor 3-alpha; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D051543:Hepatocyte Nuclear Factor 3-gamma; D051542:Hepatocyte Nuclear Factor 3-beta