title: GT-2: a transcription factor with twin autonomous DNA-binding domains of closely related but different target sequence specificity.
abstract: A triplet of adjacent, highly similar GT motifs in the phyA promoter of rice functions to support maximal expression of this gene. We have obtained a recombinant clone that encodes a full-length nuclear protein, designated GT-2, which binds specifically to these target sequences. This novel protein contains acidic, basic and proline- + glutamine-rich regions, as well as two autonomous DNA-binding domains, one NH2-terminal and the other COOH-terminal, that discriminate with high resolution between the three GT motifs. A duplicated sequence of 75 amino acids, present once in each DNA-binding domain, appears likely to mediate DNA target element recognition. Each copy of this duplicated protein sequence is predicted to form three amphipathic alpha-helices separated from each other by two short loops. The absence of sequence similarity to other known proteins suggests that this predicted structural unit, which we term the trihelix motif, might be representative of a new class of DNA-binding proteins.
authors.affiliation: University of California, Berkeley.
authors.forename: K
authors.initials: K
authors.lastname: Dehesh
authors.forename: H
authors.initials: H
authors.lastname: Hung
authors.forename: J M
authors.initials: JM
authors.lastname: Tepperman
authors.forename: P H
authors.initials: PH
authors.lastname: Quail
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D003850:Deoxyribonuclease I; D005091:Exons; D007438:Introns; D008961:Models, Structural; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D010834:Phytochrome / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D010940:Plant Proteins
chemical_list: D004247:DNA; D004268:DNA-Binding Proteins; D003850:Deoxyribonuclease I; D010834:Phytochrome; D011994:Recombinant Proteins; D014157:Transcription Factors; C077393:rice nuclear protein GT-2; D010940:Plant Proteins