Non-Axial View of the Varicella-Zoster Virus Portal Protein Reveals Conserved Crown, Wing and Clip Architecture

Abstract

<b><i>Background:</i></b> Herpesviridae encode a family of protein homologues that function as the ‘port of entry' for insertion of the viral DNA into preformed capsids during encapsidation. <b><i>Methods:</i></b> Transmission electron microscopy (TEM) of recombinant varicella-zoster virus pORF54 was performed. <b><i>Results:</i></b> Results suggest that pORF54 forms higher-order structures with itself. Enriched fractions analyzed by TEM revealed non-axial oriented portals with defined central channels and distinguishable crown, wing and clip regions. <b><i>Conclusion:</i></b> These morphological features are consistent with those previously reported for other herpesvirus and bacteriophage portal proteins.