Solution structure of an Arabidopsis WRKY DNA binding domain.
The WRKY proteins comprise a major family of transcription factors that are essential in pathogen and salicylic acid responses of higher plants as well as a variety of plant-specific reactions. They share a DNA binding domain, designated as the WRKY domain, which contains an invariant WRKYGQK sequence and a CX4-5CX22-23HXH zinc binding motif. Herein, we report the NMR solution structure of the C-terminal WRKY domain of the Arabidopsis thaliana WRKY4 protein. The structure consists of a four-stranded beta-sheet, with a zinc binding pocket formed by the conserved Cys/His residues located at one end of the beta-sheet, revealing a novel zinc and DNA binding structure. The WRKYGQK residues correspond to the most N-terminal beta-strand, kinked in the middle of the sequence by the Gly residue, which enables extensive hydrophobic interactions involving the Trp residue and contributes to the structural stability of the beta-sheet. Based on a profile of NMR chemical shift perturbations, we propose that the same strand enters the DNA groove and forms contacts with the DNA bases.
Yamasaki
Kazuhiko
K
Age Dimension Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan. k-yamasaki@aist.go.jp
Kigawa
Takanori
T
Inoue
Makoto
M
Tateno
Masaru
M
Yamasaki
Tomoko
T
Yabuki
Takashi
T
Aoki
Masaaki
M
Seki
Eiko
E
Matsuda
Takayoshi
T
Tomo
Yasuko
Y
Hayami
Nobuhiro
N
Terada
Takaho
T
Shirouzu
Mikako
M
Tanaka
Akiko
A
Seki
Motoaki
M
Shinozaki
Kazuo
K
Yokoyama
Shigeyuki
S
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D012996:Solutions; D055672:Static Electricity; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D012996:Solutions; D014157:Transcription Factors