title: DNA secondary structure of the released strand stimulates WRN helicase action on forked duplexes without coordinate action of WRN exonuclease.
abstract: Werner syndrome (WS) is an autosomal recessive premature aging disorder characterized by aging-related phenotypes and genomic instability. WS is caused by mutations in a gene encoding a nuclear protein, Werner syndrome protein (WRN), a member of the RecQ helicase family, that interestingly possesses both helicase and exonuclease activities. Previous studies have shown that the two activities act in concert on a single substrate. We investigated the effect of a DNA secondary structure on the two WRN activities and found that a DNA secondary structure of the displaced strand during unwinding stimulates WRN helicase without coordinate action of WRN exonuclease. These results imply that WRN helicase and exonuclease activities can act independently, and we propose that the uncoordinated action may be relevant to the in vivo activity of WRN.
authors.affiliation: Department of Life Sciences, University of Ulsan, South Korea. bbccahn@mail.ulsan.ac.kr
authors.forename: Byungchan
authors.initials: B
authors.lastname: Ahn
authors.forename: Vilhelm A
authors.initials: VA
authors.lastname: Bohr
mesh_terms: D004247:DNA / Q000737:chemistry*; D005090:Exodeoxyribonucleases / Q000737:chemistry*; D006801:Humans; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry; D053484:RecQ Helicases / Q000737:chemistry*; D013379:Substrate Specificity; D014898:Werner Syndrome / Q000201:enzymology*; D000071657:Werner Syndrome Helicase
chemical_list: D009841:Oligonucleotides; D004247:DNA; D005090:Exodeoxyribonucleases; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase