title: Characterization of DNA-binding activity of Z alpha domains from poxviruses and the importance of the beta-wing regions in converting B-DNA to Z-DNA.
abstract: The E3L gene is essential for pathogenesis in vaccinia virus. The E3L gene product consists of an N-terminal Z alpha domain and a C-terminal double-stranded RNA (dsRNA) binding domain; the left-handed Z-DNA-binding activity of the Z alpha domain of E3L is required for viral pathogenicity in mice. E3L is highly conserved among poxviruses, including the smallpox virus, and it is likely that the orthologous Z alpha domains play similar roles. To better understand the biological function of E3L proteins, we have investigated the Z-DNA-binding behavior of five representative Z alpha domains from poxviruses. Using surface plasmon resonance (SPR), we have demonstrated that these viral Z alpha domains bind Z-DNA tightly. Ability of Z alpha(E3L) converting B-DNA to Z-DNA was measured by circular dichroism (CD). The extents to which these Z alphas can stabilize Z-DNA vary considerably. Mutational studies demonstrate that residues in the loop of the beta-wing play an important role in this stabilization. Notably the Z alpha domain of vaccinia E3L acquires ability to convert B-DNA to Z-DNA by mutating amino acid residues in this region. Differences in the host cells of the various poxviruses may require different abilities to stabilize Z-DNA; this may be reflected in the observed differences in behavior in these Zalpha proteins.
authors.affiliation: Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea.
authors.forename: Dong Van
authors.initials: DV
authors.lastname: Quyen
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Ha
authors.forename: Ky
authors.initials: K
authors.lastname: Lowenhaupt
authors.forename: Alexander
authors.initials: A
authors.lastname: Rich
authors.forename: Kyeong Kyu
authors.initials: KK
authors.lastname: Kim
authors.forename: Yang-Gyun
authors.initials: YG
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D018147:Chordopoxvirinae; D004247:DNA / Q000737:chemistry; D043542:DNA, Z-Form / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D020349:Surface Plasmon Resonance; D013912:Threonine / Q000737:chemistry; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D043542:DNA, Z-Form; D004268:DNA-Binding Proteins; C081374:E3L protein, Vaccinia virus; D016601:RNA-Binding Proteins; D014764:Viral Proteins; D013912:Threonine; D004247:DNA; D008239:Lysine