title: Structural characterization of the BH3-like motif of hepatitis B virus X protein.
abstract: Hepatitis B virus X protein (HBx) is a multifunctional protein, which is considered to be an essential molecule for viral replication and the development of liver diseases. Recently, it has been demonstrated that HBx can directly interact with Bcl-2 and Bcl-xL through a sequence (termed the BH3-like motif) that is related to the BH3 motif of pro-apoptotic BH3-only proteins. Here, we present the first structural characterization of the HBx BH3-like motif by circular dichroism and NMR spectroscopies. Our results demonstrated that the HBx BH3-like motif has the ability to form an α-helix, and the potential helical region involves residues L108-L134. This is a common characteristic among the BH3 peptides of pro-apoptotic BH3-only proteins, implying that HBx may interact with Bcl-2 and Bcl-xL, by forming an α-helix, similar to the interaction mode of other BH3 peptides with Bcl-2 and Bcl-xL.
authors.affiliation: Department of Research on Blood and Biological Products, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashi-Murayama-shi, Tokyo 208-0011, Japan. Electronic address: kusunoki@niid.go.jp.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kusunoki
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Biochemistry, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kohno
authors.affiliation: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Wakamatsu
authors.affiliation: Department of Research on Blood and Biological Products, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashi-Murayama-shi, Tokyo 208-0011, Japan. Electronic address: 130hama@niid.go.jp.
authors.forename: Isao
authors.initials: I
authors.lastname: Hamaguchi
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry* / Q000648:ultrastructure*; D011487:Protein Conformation; D011518:Proto-Oncogene Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D015534:Trans-Activators / Q000737:chemistry* / Q000648:ultrastructure*; D054334:Viral Regulatory and Accessory Proteins; D014867:Water / Q000737:chemistry*
chemical_list: C474007:Bax protein (53-86); D010446:Peptide Fragments; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D014867:Water
keywords: BH3 motif; CD; HBV; HBx; NMR