title: Analysis of helicase activity and substrate specificity of Drosophila RECQ5.
abstract: RecQ5 is one of five RecQ helicase homologs identified in humans. Three of the human RecQ homologs (BLM, WRN and RTS) have been linked to autosomal recessive human genetic disorders (Bloom syndrome, Werner syndrome and Rothmund-Thomson syndrome, respectively) that display increased genomic instability and cause elevated levels of cancers in addition to other symptoms. To understand the role of RecQ helicases in maintaining genomic stability, the WRN, BLM and Escherichia coli RecQ helicases have been characterized in terms of their DNA substrate specificity. However, little is known about other members of the RecQ family. Here we show that Drosophila RECQ5 helicase is a structure-specific DNA helicase like the other RecQ helicases biochemically characterized so far, although the substrate specificity is not identical to that of WRN and BLM helicases. Drosophila RECQ5 helicase is capable of unwinding 3' Flap, three-way junction, fork and three-strand junction substrates at lower protein concentrations compared to 5' Flap, 12 nt bubble and synthetic Holliday junction structures, which can be unwound efficiently by WRN and BLM.
authors.affiliation: Curriculum in Genetics and Molecular Biology and. Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: A Zeynep
authors.initials: AZ
authors.lastname: Ozsoy
authors.forename: Heather M
authors.initials: HM
authors.lastname: Ragonese
authors.forename: Steven W
authors.initials: SW
authors.lastname: Matson
mesh_terms: D000818:Animals; D001483:Base Sequence; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication / Q000235:genetics; D004330:Drosophila / Q000201:enzymology*; D024202:Electrophoretic Mobility Shift Assay; D007700:Kinetics; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D053484:RecQ Helicases; D013379:Substrate Specificity
chemical_list: D009841:Oligonucleotides; C506732:RECQL5 protein, human; D004265:DNA Helicases; D053484:RecQ Helicases