title: Crystal Structure of Human Herpesvirus 6B Tegument Protein U14.
abstract: The tegument protein U14 of human herpesvirus 6B (HHV-6B) constitutes the viral virion structure and is essential for viral growth. To define the characteristics and functions of U14, we determined the crystal structure of the N-terminal domain of HHV-6B U14 (U14-NTD) at 1.85 Å resolution. U14-NTD forms an elongated helix-rich fold with a protruding β hairpin. U14-NTD exists as a dimer exhibiting broad electrostatic interactions and a network of hydrogen bonds. This is first report of the crystal structure and dimerization of HHV-6B U14. The surface of the U14-NTD dimer reveals multiple clusters of negatively- and positively-charged residues that coincide with potential functional sites of U14. Three successive residues, L424, E425 and V426, which relate to viral growth, reside on the β hairpin close to the dimer's two-fold axis. The hydrophobic side-chains of L424 and V426 that constitute a part of a hydrophobic patch are solvent-exposed, indicating the possibility that the β hairpin region is a key functional site of HHV-6 U14. Structure-based sequence comparison suggests that U14-NTD corresponds to the core fold conserved among U14 homologs, human herpesvirus 7 U14, and human cytomegalovirus UL25 and UL35, although dimerization appears to be a specific feature of the U14 group.
authors.affiliation: Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Bochao
authors.initials: B
authors.lastname: Wang
authors.affiliation: Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Huamin
authors.initials: H
authors.lastname: Tang
authors.affiliation: Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kawabata
authors.affiliation: Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.|Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt.
authors.forename: Nora F
authors.initials: NF
authors.lastname: Mahmoud
authors.affiliation: Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Khanlari
authors.affiliation: Center for Applied Structural Science, Center for Collaborative Research and Technology Development, Kobe University, Kobe, Japan.
authors.forename: Daizo
authors.initials: D
authors.lastname: Hamada
authors.affiliation: Center for Applied Structural Science, Center for Collaborative Research and Technology Development, Kobe University, Kobe, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tsuruta
authors.affiliation: Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018360:Crystallography, X-Ray; D015654:Herpesvirus 6, Human / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D015678:Viral Structural Proteins / Q000737:chemistry*
chemical_list: D015678:Viral Structural Proteins