Publikationsdatenbank

Characterization of human herpesvirus 6A/B U94 as ATPase, helicase, exonuclease and DNA-binding proteins (2015)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Trempe, Frédéric

Gravel, Annie

Dubuc, Isabelle

Wallaschek, Nina (WE 5)

Collin, Vanessa

Gilbert-Girard, Shella

Morissette, Guillaume

Kaufer, Benedikt B (WE 5)

Flamand, Louis

Quelle

Nucleic acids research

Bandzählung: 43

Heftzählung: 12

Seiten: 6084 – 6098

ISSN: 1362-4962

Sprache

Englisch

Verweise

URL (Volltext): http://edocs.fu-berlin.de/docs/receive/FUDOCS_document_000000023066

DOI: 10.1093/nar/gkv503

Pubmed: 25999342

Kontakt

Institut für Virologie

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51833
virologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Human herpesvirus-6A (HHV-6A) and HHV-6B integrate their genomes into the telomeres of human chromosomes, however, the mechanisms leading to integration remain unknown. HHV-6A/B encode a protein that has been proposed to be involved in integration termed U94, an ortholog of adeno-associated virus type 2 (AAV-2) Rep68 integrase. In this report, we addressed whether purified recombinant maltose-binding protein (MBP)-U94 fusion proteins of HHV-6A/B possess biological functions compatible with viral integration. We could demonstrate that MBP-U94 efficiently binds both dsDNA and ssDNA containing telomeric repeats using gel shift assay and surface plasmon resonance. MBP-U94 is also able to hydrolyze adenosine triphosphate (ATP) to ADP, providing the energy for further catalytic activities. In addition, U94 displays a 3' to 5' exonuclease activity on dsDNA with a preference for 3'-recessed ends. Once the DNA strand reaches 8-10 nt in length, the enzyme dissociates it from the complementary strand. Lastly, MBP-U94 compromises the integrity of a synthetic telomeric D-loop through exonuclease attack at the 3' end of the invading strand. The preferential DNA binding of MBP-U94 to telomeric sequences, its ability to hydrolyze ATP and its exonuclease/helicase activities suggest that U94 possesses all functions required for HHV-6A/B chromosomal integration.