The A, B, Cs of herpesvirus capsids.
Assembly of herpesvirus nucleocapsids shares significant similarities with the assembly of tailed dsDNA bacteriophages; however, important differences exist. A unique feature of herpesviruses is the presence of different mature capsid forms in the host cell nucleus during infection. These capsid forms, referred to as A-, B-, and C-capsids, represent empty capsids, scaffold containing capsids and viral DNA containing capsids, respectively. The C-capsids are the closest in form to those encapsidated into mature virions and are considered precursors to infectious virus. The evidence supporting A- and B-capsids as either abortive forms or assembly intermediates has been lacking. Interaction of specific capsid forms with viral tegument proteins has been proposed to be a mechanism for quality control at the point of nuclear egress of mature particles. Here, we will review the available literature on these capsid forms and present data to debate whether A- and B-capsids play an important or an extraneous role in the herpesvirus life cycle.
Department of Microbiology and Immunology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA. rtandon@umc.edu.
Ritesh
R
Tandon
Department of Microbiology and Immunology, Emory University School of Medicine, 1462 Clifton Road, Atlanta, GA 30322, USA. mocarski@emory.edu.
Edward S
ES
Mocarski
Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 5th Avenue, Pittsburgh, PA 15260, USA. jxc100@pitt.edu.
James F
JF
Conway
D002213:Capsid / Q000378:metabolism*; D006564:Herpesviridae / Q000502:physiology*; D046911:Macromolecular Substances / Q000378:metabolism; D019065:Virus Assembly
D046911:Macromolecular Substances