title: The Arabidopsis SUPERMAN protein is able to specifically bind DNA through its single Cys2-His2 zinc finger motif.
abstract: The Arabidopsis SUPERMAN (SUP) gene has been shown to be important in maintaining the boundary between stamens and carpels, and is presumed to act by regulating cell proliferation. In this work, we show that the SUP protein, which contains a single Cys2-His2 zinc finger domain including the QALGGH sequence, highly conserved in the plant zinc finger proteins, binds DNA. Using a series of deletion mutants, it was determined that the minimal domain required for specific DNA binding (residues 15-78) includes the single zinc finger and two basic regions located on either side of this motif. Furthermore, amino acid substitutions in the zinc finger or in the basic regions, including a mutation that knocks out the function of the SUP protein in vivo (glycine 63 to aspartate), have been found to abolish the activity of the SUP DNA-binding domain. These results strongly suggest that the SUP protein functions in vivo by acting as a DNA-binding protein, likely involved in transcriptional regulation. The association of both an N-terminal and a C-terminal basic region with a single Cys2-His2 zinc finger represents a novel DNA-binding motif suggesting that the mechanism of DNA recognition adopted by the SUP protein is different from that described so far in other zinc finger proteins.
authors.affiliation: Istituto di Biostrutture e Bioimmagini, Via Mezzocannone 6, 80134 Napoli, Italy.
authors.forename: Nina
authors.initials: N
authors.lastname: Dathan
authors.forename: Laura
authors.initials: L
authors.lastname: Zaccaro
authors.forename: Sabrina
authors.initials: S
authors.lastname: Esposito
authors.forename: Carla
authors.initials: C
authors.lastname: Isernia
authors.forename: James G
authors.initials: JG
authors.lastname: Omichinski
authors.forename: Andrea
authors.initials: A
authors.lastname: Riccio
authors.forename: Carlo
authors.initials: C
authors.lastname: Pedone
authors.forename: Benedetto
authors.initials: B
authors.lastname: Di Blasio
authors.forename: Roberto
authors.initials: R
authors.lastname: Fattorusso
authors.forename: Paolo V
authors.initials: PV
authors.lastname: Pedone
mesh_terms: D000595:Amino Acid Sequence; D024361:Amino Acids, Basic / Q000502:physiology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D003545:Cysteine / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D006639:Histidine / Q000378:metabolism; D008969:Molecular Sequence Data; D017384:Sequence Deletion; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers
chemical_list: D024361:Amino Acids, Basic; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C096661:superman protein, Arabidopsis; D006639:Histidine; D004247:DNA; D003545:Cysteine