title: The Zβ domain of human DAI binds to Z-DNA via a novel B-Z transition pathway.
abstract: The human DNA-dependent activator of IFN-regulatory factor (DAI) protein, which activates the innate immune response in response to DNA, contains two tandem Z-DNA binding domains (Zα and Zβ) at the NH(2) terminus. The hZβ(DAI) structure is similar to other Z-DNA binding proteins, although it demonstrates an unusual Z-DNA recognition. We performed NMR experiments on complexes of hZβ(DAI) with DNA duplex, d(CGCGCG)(2), at a variety of protein-to-DNA molar ratios. The results suggest that hZβ(DAI) binds to Z-DNA via an active-di B-Z transition mechanism, where two hZβ(DAI) proteins bind to B-DNA to form the hZβ(DAI)-B-DNA complex; the B-DNA is subsequently converted to left-handed Z-DNA. This novel mechanism of DNA binding and B-Z conversion is distinct from Z-DNA binding of the human ADAR1 protein.
authors.affiliation: Department of Chemistry and RINS, Gyeongsang National University, Jinju, Gyeongnam 660-701, Republic of Korea.
authors.forename: Hee-Eun
authors.initials: HE
authors.lastname: Kim
authors.forename: Hee-Chul
authors.initials: HC
authors.lastname: Ahn
authors.forename: Yeon-Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Eun-Hae
authors.initials: EH
authors.lastname: Lee
authors.forename: Yeo-Jin
authors.initials: YJ
authors.lastname: Seo
authors.forename: Yang-Gyun
authors.initials: YG
authors.lastname: Kim
authors.forename: Kyeong Kyu
authors.initials: KK
authors.lastname: Kim
authors.forename: Byong-Seok
authors.initials: BS
authors.lastname: Choi
authors.forename: Joon-Hwa
authors.initials: JH
authors.lastname: Lee
mesh_terms: D001483:Base Sequence; D043542:DNA, Z-Form / Q000737:chemistry* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D004058:Diffusion; D006801:Humans; D007700:Kinetics; D008280:Magnetics; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011522:Protons; D016601:RNA-Binding Proteins; D017186:Titrimetry
chemical_list: D043542:DNA, Z-Form; D004268:DNA-Binding Proteins; D011522:Protons; D016601:RNA-Binding Proteins; C485731:ZBP1 protein, human