The Varicella-zoster virus ORF54 gene product encodes the capsid portal protein, pORF54.

The Varicella-zoster virus (VZV) ORF54 gene was characterized using a guinea pig antiserum prepared to a GST-pORF54 fusion protein. A protein of the predicted size, 87kDa, was detected in VZV-infected MeWo cells but not in mock-infected cells. Sucrose density gradient fractionation of pORF54 expressed in a recombinant baculovirus system resulted in samples containing enriched amounts of pORF54. Electron microscopic analysis suggested that the ORF54 gene encodes a protein that assembles into ring-like portal structures similar to those observed for numerous bacteriophages and other herpesviruses.