JVI Figure table search 04
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 Feng, Y.-X.
Right arrow Articles by Rein, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Feng, Y.-X.
Right arrow Articles by Rein, A.

 Previous Article  |  Next Article 

Journal of Virology, May 1999, p. 4251-4256, Vol. 73, No. 5
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

The Human Immunodeficiency Virus Type 1 Gag Polyprotein Has Nucleic Acid Chaperone Activity: Possible Role in Dimerization of Genomic RNA and Placement of tRNA on the Primer Binding Site

Ya-Xiong Feng,1 Stephen Campbell,1 Demetria Harvin,1 Bernard Ehresmann,2 Chantal Ehresmann,2 and Alan Rein1,*

Retroviral Genetics Section, ABL-Basic Research Program, National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, Maryland 21702,1 and Unité Propre de Recherche du CNRS no. 9002, Institut de Biologie Moleculaire et Cellulaire (IBMC), 67084 Strasbourg Cedex, France2

Received 11 November 1998/Accepted 13 February 1999

The formation of an infectious retrovirus particle requires several RNA-RNA interaction events. In particular, the genomic RNA molecules form a dimeric structure, and a cellular tRNA molecule is annealed to an 18-base complementary region (the primer binding site, or PBS) on the genomic RNA, where it will serve as primer for reverse transcription. tRNAs normally possess a highly stable secondary and tertiary structure; it seems unlikely that annealing of a tRNA molecule to the PBS, which involves unwinding of this structure, could occur efficiently at physiological temperatures without the assistance of a cofactor. Many prior studies have shown that the viral nucleocapsid (NC) protein can act as a nucleic acid chaperone (i.e., facilitate annealing events between nucleic acids), and the assays used to demonstrate this activity include its ability to catalyze dimerization of transcripts representing retroviral genomes and the annealing of tRNA to the PBS in vitro. However, mature NC is not required for these events in vivo, since protease-deficient viral mutants, in which NC is not cleaved from the parental Gag polyprotein, are known to contain dimeric RNAs with tRNA annealed to the PBS. In the present experiments, we have tested recombinant human immunodeficiency virus type 1 Gag polyprotein for nucleic acid chaperone activity. The protein was positive by all of our assays, including the ability to stimulate dimerization and to anneal tRNA to the PBS in vitro. In quantitative experiments, its activity was approximately equivalent on a molar basis to that of NC. Based on these results, we suggest that the Gag polyprotein (presumably by its NC domain) catalyzes the annealing of tRNA to the PBS during (or before) retrovirus assembly in vivo.

* Corresponding author. Mailing address: Retroviral Genetics Section, ABL-BRP, NCI-Frederick Cancer Research & Development Center, P.O. Box B, Bldg. 535, Frederick, MD 21702. Phone: (301) 846-1361. Fax: (301) 846-7146. E-mail: rein{at}mail.ncifcrf.gov.

Journal of Virology, May 1999, p. 4251-4256, Vol. 73, No. 5
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Mol. Cell. Biol. Microbiol. Mol. Biol. Rev.
Clin. Vaccine Immunol. ALL ASM JOURNALS

Copyright © 1999 by the American Society for Microbiology. All rights reserved.