Structure of simian virus 40 DNA replicated by herpes simplex virus type 1.
Replicating herpes simplex virus type 1 (HSV-1) DNA is known to form large branched structures. The aim of this study was to define whether HSV-1-specific DNA elements in cis play a critical role in formation of this structure. We did this by investigating the structure of heterologous simian virus 40 (SV40) DNA, which is replicated in HSV-infected cells by SV40 large T-antigen and defined HSV-encoded replication factors (e.g., DNA polymerase, single-stranded DNA-binding protein, and helicase-primase). During this process, extrachromosomal concatemeric DNA replication products are formed, indicating a herpesvirus-specific replication mode. In this study, we found that the replicating SV40 DNA consisted of a complex branched structure indistinguishable from that of replicating HSV DNA. Thus, no HSV-specific DNA element is necessary in cis for the formation of the large branched structure during HSV DNA replication. The trans-acting HSV DNA replication proteins seem to be sufficient to generate these complex structures. Moreover, replicating SV40 DNA showed a high frequency of homologous recombination events, which is typical for HSV DNA replication. However, in contrast to HSV origin-bearing amplicon plasmids, SV40 plasmids bearing the HSV cleavage-packaging signal were not efficiently processed to linear 150-kb DNA packaged into HSV capsids. This indicates that initiation of DNA synthesis on HSV-ori determines some, yet undefined, property of replicating HSV DNA, which is crucial for regular processing of the replication intermediates to daughter genomes.
Blümel
J
J
Institut für Medizinische Mikrobiologie und Immunologie, Universität Bonn, Sigmund-Freud-Strasse 25, Bonn, D-53127, Germany. blujo@pei.de
Gräper
S
S
Matz
B
B
D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D006224:Cricetinae; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis / Q000737:chemistry*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli; D018259:Herpesvirus 1, Human / Q000737:chemistry / Q000235:genetics*; D009690:Nucleic Acid Conformation; D011995:Recombination, Genetic; D013539:Simian virus 40 / Q000737:chemistry / Q000235:genetics*; D014709:Vero Cells
D004279:DNA, Viral