title: Characterization of the Caenorhabditis elegans HIM-6/BLM helicase: unwinding recombination intermediates.
abstract: Mutations in three human RecQ genes are implicated in heritable human syndromes. Mutations in BLM, a RecQ gene, cause Bloom syndrome (BS), which is characterized by short stature, cancer predisposition, and sensitivity to sunlight. BLM is a RecQ DNA helicase that, with interacting proteins, is able to dissolve various DNA structures including double Holliday junctions. A BLM ortholog, him-6, has been identified in Caenorhabditis elegans, but little is known about its enzymatic activities or its in vivo roles. By purifying recombinant HIM-6 and performing biochemical assays, we determined that the HIM-6 has DNA-dependent ATPase activity HIM-6 and helicase activity that proceeds in the 3'-5' direction and needs at least five 3' overhanging nucleotides. HIM-6 is also able to unwind DNA structures including D-loops and Holliday junctions. Worms with him-6 mutations were defective in recovering the cell cycle arrest after HU treatment. These activities strongly support in vivo roles for HIM-6 in processing recombination intermediates.
authors.affiliation: Department of Life Sciences, University of Ulsan, Ulsan, Republic of Korea.
authors.forename: Hana
authors.initials: H
authors.lastname: Jung
authors.affiliation: Department of Life Sciences, University of Ulsan, Ulsan, Republic of Korea.
authors.forename: Jin A
authors.initials: JA
authors.lastname: Lee
authors.affiliation: Department of Life Sciences, University of Ulsan, Ulsan, Republic of Korea.
authors.forename: Seoyoon
authors.initials: S
authors.lastname: Choi
authors.affiliation: Department of Life Sciences, University of Ulsan, Ulsan, Republic of Korea.
authors.forename: Hyunwoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Life Sciences, University of Ulsan, Ulsan, Republic of Korea.
authors.forename: Byungchan
authors.initials: B
authors.lastname: Ahn
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000502:physiology*; D053903:DNA Breaks, Double-Stranded; D018076:DNA, Complementary / Q000235:genetics; D045566:DNA, Cruciform; D018509:DNA, Helminth / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D008540:Meiosis; D008969:Molecular Sequence Data; D053484:RecQ Helicases / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D011995:Recombination, Genetic; D016196:S Phase; D013379:Substrate Specificity
chemical_list: D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D045566:DNA, Cruciform; D018509:DNA, Helminth; C487047:HIM-6 protein, C elegans; D011993:Recombinant Fusion Proteins; D000255:Adenosine Triphosphate; C097151:Bloom syndrome protein; D053484:RecQ Helicases