Crystal Structure of Human Herpesvirus 6B Tegument Protein U14.
Wang, B., Nishimura, M., Tang, H., Kawabata, A., Mahmoud, N.F., Khanlari, Z., Hamada, D., Tsuruta, H., Mori, Y.(2016) PLoS Pathog 12: e1005594-e1005594
- PubMed: 27152739 
- DOI: https://doi.org/10.1371/journal.ppat.1005594
- Primary Citation of Related Structures:  
5B1Q - PubMed 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.
Organizational Affiliation: 
Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan.