Affiliation:
1. Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
2. Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA
Abstract
ABSTRACT
Herpes simplex virus 1 (HSV-1), the prototypic member of herpesviruses, employs a virally encoded molecular machine called terminase to package the viral double-stranded DNA (dsDNA) genome into a preformed protein shell. The terminase contains a large subunit that is thought to cleave concatemeric viral DNA during the packaging initiation and completion of each packaging cycle and supply energy to the packaging process via ATP hydrolysis. We have determined the X-ray structure of the C-terminal domain of the terminase large-subunit pUL15 (pUL15C) from HSV-1. The structure shows a fold resembling those of bacteriophage terminases, RNase H, integrases, DNA polymerases, and topoisomerases, with an active site clustered with acidic residues. Docking analysis reveals a DNA-binding surface surrounded by flexible loops, indicating considerable conformational changes upon DNA binding.
In vitro
assay shows that pUL15C possesses non-sequence-specific, Mg
2+
-dependent nuclease activity. These results suggest that pUL15 uses an RNase H-like, metal ion-mediated catalysis mechanism for cleavage of viral concatemeric DNA. The structure reveals extra structural elements in addition to the RNase H-like fold core and variations in local architecture of the nuclease active site, which are conserved in herpesvirus terminases and bear great similarity to the phage T4 gp17 but are distinct from podovirus and siphovirus orthologs and cellular RNase H, delineating a new evolutionary lineage among a large family of eukaryotic viruses and simple and complex prokaryotic viruses.
Publisher
American Society for Microbiology
Subject
Virology,Insect Science,Immunology,Microbiology
Reference51 articles.
1. RoizmanB KnipeDM WhitleyRJ. 2007. Herpes simplex virus, p 2501–2601. In KnipeDM HowleyPM GriffinDE LambRA MartinMA RoizmanB StrausSE (ed), Fields virology, 5 ed. Lippincott Williams & Wilkins, Philadelphia, PA.
2. RoizmanB
FurlongD. 1974. Comprehensive virology p 229–403. In Fraenkel-ConratH
WagnerR (ed). Plenum New York NY.
3. StevenAC
SpearPG. 1997. Structural biology of viruses p 312–351. In ChiuW
BurnettRM
GarceaRL (ed). Oxford University Press New York NY.
4. Functional domains within the a sequence involved in the cleavage-packaging of herpes simplex virus DNA
5. The cleavage recognition signal is contained within sequences surrounding an a-a junction in herpes simplex virus DNA;Nasseri M;Virology,1988
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