Probing of HIV-1 integrase/DNA interactions using novel analogs of viral DNA

Julia Agapkina, Maksim Smolov, Sophie Barbe, Evgenii Zubin, Timofei Zatsepin, Eric Deprez, Marc Le Bret, Jean François Mouscadet, Marina Gottikh

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)

Abstract

The specific activity of the human immunodeficiency virus, type 1 (HIV-1), integrase on the viral long terminal repeat requires the binding of the enzyme to certain sequences located in the U3 and U5 regions at the ends of viral DNA, but the determinants of this specific DNA-protein recognition are not yet completely understood. We synthesized DNA duplexes mimicking the U5 region and containing either 2′-modified nucleosides or 1,3-propanediol insertions and studied their interactions with HIV-1 integrase, using Mn2+ or Mg2+ ions as integrase cofactors. These DNA modifications had no strong effect on integrase binding to the substrate analogs but significantly affected 3′-end processing rate. The effects of nucleoside modifications at positions 5, 6, and especially 3 strongly depended on the cationic cofactor used. These effects were much more pronounced in the presence of Mg2+ than in the presence of Mn2+. Modifications of base pairs 7-9 affected 3′-end processing equally in the presence of both ions. Adenine from the 3rd bp is thought to form at least two hydrogen bonds with integrase that are crucial for specific DNA recognition. The complementary base, thymine, is not important for integrase activity. For other positions, our results suggest that integrase recognizes a fine structure of the sugar-phosphate backbone rather than heterocyclic bases. Integrase interactions with the unprocessed strand at positions 5-8 are more important than interactions with the processed strand for specific substrate recognition. Based on our results, we suggest a model for integrase interaction with the U5 substrate.

Original languageEnglish
Pages (from-to)11530-11540
Number of pages11
JournalJournal of Biological Chemistry
Volume281
Issue number17
DOIs
Publication statusPublished - 28 Apr 2006
Externally publishedYes

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