title: Herpes simplex virus DNA cleavage and packaging: association of multiple forms of U(L)15-encoded proteins with B capsids requires at least the U(L)6, U(L)17, and U(L)28 genes.
abstract: The U(L)15 gene of herpes simplex virus (HSV) is one of several genes required for the packaging of viral DNA into intranuclear B capsids to produce C capsids that become enveloped at the inner nuclear membrane. A rabbit antiserum directed against U(L)15-encoded protein recognized three proteins with apparent Mrs of 79,000, 80,000, and 83,000 in highly purified B capsids. The 83,000-Mr protein was detected in type C capsids and comigrated with the product of a U(L)15 cDNA transcribed and translated in vitro. The 83,000- and 80,000-Mr proteins were readily detected in purified virions. Inasmuch as (i) none of these proteins were detectable in capsids purified from cells infected with HSV-1(deltaU(L)15), a virus lacking an intact U(L)15 gene, and (ii) corresponding proteins in capsids purified from cells infected with a recombinant virus [HSV-1(R7244), containing a 20-codon tag at the 3' end of U(L)15] were decreased in electrophoretic mobility relative to the wild-type proteins, we conclude that the proteins with apparent Mrs of 83,000, 80,000, and 79,000 are products of U(L)15 with identical C termini. The 79,000-, 80,000-, and 83,000-Mr proteins remained associated with B capsids in the presence of 0.5 M guanidine HCl and remained detectable in capsids treated with 2.0 M guanidine HCl and lacking proteins associated with the capsid core. These data, therefore, indicate that U(L)15-encoded proteins are integral components of B capsids. Only the 83,000-Mr protein was detected in B capsids purified from cells infected with viruses lacking the U(L)6, U(L)17, or U(L)28 genes, which are required for DNA cleavage and packaging, suggesting that capsid association of the 80,000- and 79,000-Mr proteins requires intact cleavage and packaging machinery. These data, therefore, indicate that capsid association of the 80,000- and 79,000-Mr U(L)15-encoded proteins reflects a previously unrecognized step in the DNA cleavage and packaging reaction.
authors.affiliation: Department of Microbiology and Immunology, Cornell University, Ithaca, New York 14853, USA.
authors.forename: B
authors.initials: B
authors.lastname: Salmon
authors.forename: J D
authors.initials: JD
authors.lastname: Baines
mesh_terms: D000818:Animals; D002213:Capsid / Q000235:genetics*; D036022:Capsid Proteins; D002522:Chlorocebus aethiops; D004279:DNA, Viral; D003902:Detergents / Q000494:pharmacology; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D019791:Guanidine / Q000494:pharmacology; D018259:Herpesvirus 1, Human / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D006801:Humans; D016296:Mutagenesis; D011817:Rabbits; D014709:Vero Cells; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D014771:Virion; D019065:Virus Assembly
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral; D003902:Detergents; D014764:Viral Proteins; C069185:DNA cleavage and packaging proteins, Herpesvirus; D019791:Guanidine