title: RECQ4 selectively recognizes Holliday junctions.
abstract: The RECQ4 protein belongs to the RecQ helicase family, which plays crucial roles in genome maintenance. Mutations in the RECQ4 gene are associated with three insidious hereditary disorders: Rothmund-Thomson, Baller-Gerold, and RAPADILINO syndromes. These syndromes are characterized by growth deficiency, radial ray defects, red rashes, and higher predisposition to malignancy, especially osteosarcomas. Within the RecQ family, RECQ4 is the least characterized, and its role in DNA replication and repair remains unknown. We have identified several DNA binding sites within RECQ4. Two are located at the N-terminus and one is located within the conserved helicase domain. N-terminal domains probably cooperate with one another and promote the strong annealing activity of RECQ4. Surprisingly, the region spanning 322-400aa shows a very high affinity for branched DNA substrates, especially Holliday junctions. This study demonstrates biochemical activities of RECQ4 that could be involved in genome maintenance and suggest its possible role in processing replication and recombination intermediates.
authors.affiliation: Department of Biology, Masaryk University, Brno, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Sedlackova
authors.affiliation: Department of Biology, Masaryk University, Brno, Czech Republic.
authors.forename: Barbora
authors.initials: B
authors.lastname: Cechova
authors.affiliation: Department of Biology, Masaryk University, Brno, Czech Republic.
authors.forename: Jarmila
authors.initials: J
authors.lastname: Mlcouskova
authors.affiliation: Department of Biology, Masaryk University, Brno, Czech Republic; National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic; International Clinical Research Center, Center for Biomolecular and Cellular Engineering, St. Anne's University Hospital Brno, Brno, Czech Republic. Electronic address: lkrejci@chemi.muni.cz.
authors.forename: Lumir
authors.initials: L
authors.lastname: Krejci
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D004261:DNA Replication; D045566:DNA, Cruciform / Q000378:metabolism*; D059765:Homologous Recombination; D006801:Humans; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D053484:RecQ Helicases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D045566:DNA, Cruciform; C506731:RECQL4 protein, human; D053484:RecQ Helicases
keywords: DNA binding; Genomic stability; Holliday junction; Homologous recombination; RECQ4