title: NMR structure of transcription factor Sp1 DNA binding domain.
abstract: To understand the DNA recognition mechanism of zinc finger motifs of transcription factor Sp1, we have determined the solution structure of DNA-binding domain of the Sp1 by solution NMR techniques. The DNA-binding domain of Sp1 consists of three Cys(2)His(2)-type zinc finger motifs. They have typical betabetaalpha zinc finger folds and relatively random orientations. From DNA-binding analysis performed by NMR and comparison between structures determined here and previously reported structures of other zinc fingers, it was assumed that DNA recognition modes of fingers 2 and 3 would be similar to those of fingers of Zif268, in which each finger recognizes four base pairs strictly by using residues at positions -1, 2, 3, and 6 of the recognition helix. On the contrary, finger 1 can use only two residues for DNA recognition, Lys550 and His553 at positions -1 and 3 of the helix, and has more relaxed sequence and site specificity than other Cys(2)His(2) zinc fingers. It is proposed that this relaxed property of finger 1 allows transcription factor Sp1 to bind various DNA sequences with high affinity.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Oka
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: Takuya
authors.initials: T
authors.lastname: Yoshida
authors.forename: Tadayasu
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sugiura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009587:Nitrogen Isotopes; D016415:Sequence Alignment; D016329:Sp1 Transcription Factor / Q000737:chemistry* / Q000378:metabolism
chemical_list: D009587:Nitrogen Isotopes; D016329:Sp1 Transcription Factor; D004247:DNA