This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Marintcheva, B.
Right arrow Articles by Weller, S. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marintcheva, B.
Right arrow Articles by Weller, S. K.

 Previous Article  |  Next Article 

Journal of Virology, February 2003, p. 2477-2488, Vol. 77, No. 4
0022-538X/03/$08.00+0     DOI: 10.1128/JVI.77.4.2477-2488.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Helicase Motif Ia Is Involved in Single-Strand DNA-Binding and Helicase Activities of the Herpes Simplex Virus Type 1 Origin-Binding Protein, UL9

Boriana Marintcheva and Sandra K. Weller*

Department of Microbiology, University of Connecticut Health Center, Farmington, Connecticut 06030

Received 15 July 2002/ Accepted 11 November 2002

UL9 is a multifunctional protein essential for herpes simplex virus type 1 (HSV-1) replication in vivo. UL9 is a member of the superfamily II helicases and exhibits helicase and origin-binding activities. It is thought that UL9 binds the origin of replication and unwinds it in the presence of ATP and the HSV-1 single-stranded DNA (ssDNA)-binding protein. We have previously characterized the biochemical properties of mutants in all helicase motifs except for motif Ia (B. Marintcheva and S. Weller, J. Biol. Chem. 276:6605-6615, 2001). Structural information for other superfamily I and II helicases indicates that motif Ia is involved in ssDNA binding. By analogy, we hypothesized that UL9 motif Ia is important for the ssDNA-binding function of the protein. On the basis of sequence conservation between several UL9 homologs within the Herpesviridae family and distant homology with helicases whose structures have been solved, we designed specific mutations in motif Ia and analyzed them genetically and biochemically. Mutant proteins with residues predicted to be involved in ssDNA binding (R112A and R113A/F115A) exhibited wild-type levels of intrinsic ATPase activity and moderate to severe defects in ssDNA-stimulated ATPase activity and ssDNA binding. The S110T mutation targets a residue not predicted to contact ssDNA directly. The mutant protein with this mutation exhibited wild-type levels of intrinsic ATPase activity and near wild-type levels of ssDNA-stimulated ATPase activity and ssDNA binding. All mutant proteins lack helicase activity but were able to dimerize and bind the HSV-1 origin of replication as well as wild-type UL9. Our results indicate that residues from motif Ia contribute to the ssDNA-binding and helicase activities of UL9 and are essential for viral growth. This work represents the successful application of an approach based on a combination of bioinformatics and structural information from related proteins to deduce valuable information about a protein of interest.

* Corresponding author. Mailing address: Department of Microbiology, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06030. Phone: (860) 679-2310. Fax: (860) 679-1239. E-mail: Weller{at}NSO2.uchc.edu.

Journal of Virology, February 2003, p. 2477-2488, Vol. 77, No. 4
0022-538X/03/$08.00+0     DOI: 10.1128/JVI.77.4.2477-2488.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Wang, Y., Li, H., Tang, Q., Maul, G. G., Yuan, Y. (2008). Kaposi's Sarcoma-Associated Herpesvirus ori-Lyt-Dependent DNA Replication: Involvement of Host Cellular Factors. J. Virol. 82: 2867-2882 [Abstract] [Full Text]  
  • Macao, B., Olsson, M., Elias, P. (2004). Functional Properties of the Herpes Simplex Virus Type I Origin-binding Protein Are Controlled by Precise Interactions with the Activated Form of the Origin of DNA Replication. J. Biol. Chem. 279: 29211-29217 [Abstract] [Full Text]  
  • Marintcheva, B., Weller, S. K. (2003). Existence of Transdominant and Potentiating Mutants of UL9, the Herpes Simplex Virus Type 1 Origin-Binding Protein, Suggests that Levels of UL9 Protein May Be Regulated during Infection. J. Virol. 77: 9639-9651 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»