The capsid protein gene of tobacco ringspot virus (TobRV), which had been modified to contain an amino-terminal methionine codon, was ligated into a baculovirus transfer vector downstream from the polyhedrin promoter. The resulting plasmid was cotransfected with linearized baculovirus DNA into insect cells. Recombinant baculovirus expressed high levels of the TobRV capsid protein that assembled...

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent for KS tumors, multicentric Castleman's disease, and primary effusion lymphomas. Like other herpesvirus capsids, the KSHV capsid is an icosahedral structure composed of six proteins. The capsid shell is made up of the major capsid protein, two triplex proteins, and the small capsid protein. The scaffold protein and the protea...

Viral protein-1 (VP1) is a major capsid protein of Coxsakievirus B3 (CVB3) that plays an important role in directing viruses towards permissive cells and acts as a main antigenic site of the virus in eliciting of host immune response, hence it seems VP1 can be considered as a vaccine candidate against CVB3 infection. In this study, cDNA of VP1 was prepared, cloned into pET expression vector and...

We report studies to determine which bacteriophage genes are required for assembly of phage HK97 proheads and what roles they play. We identify the gene encoding the major capsid protein of phage HK97 and report its DNA sequence, together with the DNA sequences of the two genes immediately upstream from it. When the capsid protein is expressed from a plasmid in the absence of other phage-encode...

Astroviruses are enterically transmitted viruses that cause infections in mammalian and avian species. Astroviruses are nonenveloped, icosahedral viruses comprised of a capsid protein shell and a positive-sense, single-stranded RNA genome. The capsid protein undergoes dramatic proteolytic processing both inside and outside of the host cell, resulting in a coordinated maturation process that aff...

UNLABELLED Thermus thermophilus bacteriophage P23-77 is the type member of a new virus family of icosahedral, tailless, inner-membrane-containing double-stranded DNA (dsDNA) viruses infecting thermophilic bacteria and halophilic archaea. The viruses have a unique capsid architecture consisting of two major capsid proteins assembled in various building blocks. We analyzed the function of the min...

Viral capsids ensure viral genome integrity by protecting the enclosed nucleic acids. Interactions between the genome and capsid and between individual capsid proteins (i.e., capsid architecture) are intimate and are expected to be characterized by strong evolutionary conservation. For this reason, a capsid structure-based viral classification has been proposed as a way to bring order to the vi...

The assembly and regulation of viral capsid proteins into highly ordered macromolecular complexes is essential for viral replication. Here, we utilize crystal structures of the capsid protein from the smallest and simplest known viruses capable of autonomously replicating in animal cells, circoviruses, to establish structural and mechanistic insights into capsid morphogenesis and regulation. Th...

Alphaviruses are arthropod-borne viruses that represent a significant threat to public health at a global level. While the formation of alphaviral nucleocapsid cores, consisting of cargo nucleic acid and the viral capsid protein, is an essential molecular process of infection, the precise interactions between the two partners are ill-defined. A CLIP-seq approach was used to screen for candidate...

During human immunodeficiency virus type-1 (HIV-1) virion maturation, capsid proteins undergo a major rearrangement to form a conical core that protects the viral nucleoprotein complexes. Mutations in the capsid sequence that alter the stability of the capsid core are deleterious to viral infectivity and replication. Recently, capsid assembly has become an attractive target for the development ...