title: 3' to 5' exonuclease activity of herpes simplex virus type 1 DNA polymerase modulates its strand displacement activity.
abstract: Using a minicircle DNA primer-template, the wild-type catalytic subunit of herpes simplex virus type 1 (HSV-1) DNA polymerase (pol) was shown to lack significant strand displacement activity with or without its processivity factor, UL42. However, an exonuclease-deficient (exo(-)) pol (D368A) was capable of slow strand displacement. Although UL42 increased the rate (2/s) and processivity of strand displacement by exo(-) pol, the rate was slower than that for gap-filling synthesis. High inherent excision rates on matched primer-templates and rapid idling-turnover (successive rounds of excision and polymerization) of exo-proficient polymerases correlated with poor strand displacement activity. The results suggest that the exo activity of HSV-1 pol modulates its ability to engage in strand displacement, a function that may be important to the viability and genome stability of the virus.
authors.affiliation: Department of Molecular Virology, Immunology, and Medical Genetics, Ohio State University, 333 West Tenth Avenue, Columbus, OH 43210, USA.
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhu
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Trego
authors.forename: Liping
authors.initials: L
authors.lastname: Song
authors.forename: Deborah S
authors.initials: DS
authors.lastname: Parris
mesh_terms: D001483:Base Sequence; D004247:DNA; D004279:DNA, Viral / Q000096:biosynthesis; D004259:DNA-Directed DNA Polymerase / Q000502:physiology*; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000502:physiology*; D018259:Herpesvirus 1, Human / Q000201:enzymology*; D008969:Molecular Sequence Data; D013698:Templates, Genetic; D014764:Viral Proteins / Q000502:physiology*
chemical_list: D004279:DNA, Viral; C022262:Okazaki fragments; D014764:Viral Proteins; D004247:DNA; D004259:DNA-Directed DNA Polymerase; D005090:Exodeoxyribonucleases; C043417:DNA polymerase, Simplexvirus; D043211:Exodeoxyribonuclease V