The herpes simplex virus type 1 particle: structure and molecular functions

Abstract

This review is a summary of our present knowledge with respect to the structure of the virion of herpes simplex virus type 1. The virion consists of a capsid into which the DNA is packaged, a tegument and an external envelope. The protein compositions of the structures outside the genome are described as well as the functions of individual proteins. Seven capsid proteins are identified, and two of them are mainly present in precursors of mature DNA‐containing capsids. The protein components of the 150 hexamers and 12 pentamers in the icosahedral capsid are known. These capsomers all have a central channel and are connected by Y‐shaped triplexes. In contrast to the capsid, the tegument has a less defined structure in which 11 proteins have been identified so far. Most of them are phosphorylated. Eleven virus‐encoded glycoproteins are present in the envelope, and there may be a few more membrane proteins not yet identified. Functions of these glycoproteins include attachment to and penetration of the cellular membrane. The structural proteins, their functions, coding genes and localizations are listed in table form.

Deletion of the UL21 gene in Pseudorabies virus results in the formation of DNA-deprived capsids: an electron microscopy study

“…UL33, UL28, UL15, UL12 and UL6 [1,3,4,15,19,21,23]. Ward and Roizman [26] and Haarr and Skulstad [9] reviewed herpesvirus genes that are involved in processing and/or packaging. However, they did not mention the function of UL21.…”

Herpes simplex virus type 1 tegument protein VP22 interacts with TAF-I proteins and inhibits nucleosome assembly but not regulation of histone acetylation by INHAT

“…Among the first viral proteins encountering the host cell after infection are those of the tegument, a proteinaceous layer assembled between the viral capsid and envelope and comprising at least 12 virally encoded proteins (Haarr & Skulstad, 1994). Tegument proteins are known to be involved in a variety of activities that promote virus infectivity, including, for example, shut-off of host protein synthesis (Kwong & Frenkel, 1989;Smibert et al, 1992) or the induction of transcription of the incoming genome in the nucleus (O'Hare, 1993).…”

DeNovo Infection with Rhesus Monkey Rhadinovirus Leads to theAccumulation of Multiple Intranuclear Capsid Species during LyticReplication but Favors the Release of Genome-ContainingVirions

“…Each capsid is an icosahedron with a triangulation number of 16 and consists of 162 capsomers characteristic of all members of the Herpesviridae family (25). Of the 162 capsomers, 12 are pentons, while the remaining 150 are hexons, composed of five and six subunits of the major capsid protein (MCP), respectively (24,38,40,52). In addition, the capsids have 320 triplex subunits, each consisting of a heterotrimer with ␣ 1 ␤ 2 stoichiometry.…”

“…In addition, the capsids have 320 triplex subunits, each consisting of a heterotrimer with ␣ 1 ␤ 2 stoichiometry. During lytic replication of herpesviruses, multiple capsid species arise (22,24,25,38,52). These include the three major capsid species: (i) A capsids lacking internal structures, (ii) B capsids containing an inner scaffolding protein (SCAF), and (iii) C capsids enclosing the viral genome but lacking SCAF.…”