HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 283, Issue 23, 15965-15974, June 6, 2008

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 283/23/15965    most recent M801354200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ebina, H. Articles by Levin, H. L. Search for Related Content PubMed PubMed Citation Articles by Ebina, H. Articles by Levin, H. L. Social Bookmarking                      What's this?

The GP(Y/F) Domain of TF1 Integrase Multimerizes when Present in a Fragment, and Substitutions in This Domain Reduce Enzymatic Activity of the Full-length Protein^*

From the Section on Eukaryotic Transposable Elements, Laboratory of Gene Regulation and Development, NICHD, National Institutes of Health, Bethesda, Maryland 20892

Integrases (INs) of retroviruses and long terminal repeat retrotransposons possess a C-terminal domain with DNA binding activity. Other than this binding activity, little is known about how the C-terminal domain contributes to integration. A stretch of conserved amino acids called the GP(Y/F) domain has been identified within the C-terminal IN domains of two distantly related families, the -retroviruses and the metavirus retrotransposons. To enhance understanding of the C-terminal domain, we examined the function of the GP(Y/F) domain in the IN of Tf1, a long terminal repeat retrotransposon of Schizosaccharomyces pombe. The activities of recombinant IN were measured with an assay that modeled the reverse of integration called disintegration. Although deletion of the entire C-terminal domain disrupted disintegration activity, an alanine substitution (P365A) in a conserved amino acid of the GP(Y/F) domain did not significantly reduce disintegration. When assayed for the ability to join two molecules of DNA in a reaction that modeled forward integration, the P365A substitution disrupted activity. UV cross-linking experiments detected DNA binding activity in the C-terminal domain and found that this activity was not reduced by substitutions in two conserved amino acids of the GP(Y/F) domain, G364A and P365A. Gel filtration and cross-linking of a 71-amino acid fragment containing the GP(Y/F) domain revealed a surprising ability to form dimers, trimers, and tetramers that was disrupted by the G364A and P365A substitutions. These results suggest that the GP(Y/F) residues may play roles in promoting multimerization and intermolecular strand joining.

Received for publication, February 20, 2008 , and in revised form, April 4, 2008.

^* This work was supported, in whole or in part, by the National Institutes of Health Intramural Research Program, NICHD, and the National Institutes of Health Intramural AIDS Targeted Antiviral Program. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Tables S1–S3 and Figs. S1–S4.

¹ Both authors contributed equally to this work.

² To whom correspondence should be addressed: National Institutes of Health, 18 Library Dr., Bethesda, MD 20892-5431. Tel.: 301-402-4281; Fax: 301-496-4491; E-mail: henry_levin{at}nih.gov.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. G. Chatterjee, Y. E. Leem, F. D. Kelly, and H. L. Levin The Chromodomain of Tf1 Integrase Promotes Binding to cDNA and Mediates Target Site Selection J. Virol., March 15, 2009; 83(6): 2675 - 2685. [Abstract] [Full Text] [PDF]