title: Crystal Structure of a Eukaryotic GEN1 Resolving Enzyme Bound to DNA.
abstract: We present the crystal structure of the junction-resolving enzyme GEN1 bound to DNA at 2.5 Å resolution. The structure of the GEN1 protein reveals it to have an elaborated FEN-XPG family fold that is modified for its role in four-way junction resolution. The functional unit in the crystal is a monomer of active GEN1 bound to the product of resolution cleavage, with an extensive DNA binding interface for both helical arms. Within the crystal lattice, a GEN1 dimer interface juxtaposes two products, whereby they can be reconnected into a four-way junction, the structure of which agrees with that determined in solution. The reconnection requires some opening of the DNA structure at the center, in agreement with permanganate probing and 2-aminopurine fluorescence. The structure shows that a relaxation of the DNA structure accompanies cleavage, suggesting how second-strand cleavage is accelerated to ensure productive resolution of the junction.
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
authors.forename: Yijin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
authors.forename: Alasdair D J
authors.initials: ADJ
authors.lastname: Freeman
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
authors.forename: Anne-Cécile
authors.initials: AC
authors.lastname: Déclais
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Wilson
authors.affiliation: Center for Gene Regulation and Expression, MSI/WTB Complex, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
authors.forename: Anton
authors.initials: A
authors.lastname: Gartner
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, University of Dundee, Dow Street, Dundee DD1 5EH, UK. Electronic address: d.m.j.lilley@dundee.ac.uk.
authors.forename: David M J
authors.initials: DMJ
authors.lastname: Lilley
mesh_terms: D001665:Binding Sites; D020134:Catalytic Domain; D002597:Chaetomium / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D045565:Holliday Junction Resolvases / Q000737:chemistry / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D009690:Nucleic Acid Conformation
chemical_list: D005656:Fungal Proteins; D004247:DNA; D045565:Holliday Junction Resolvases
keywords: DNA recombination; DNA repair; DNA-protein interactions; Holliday junction; X-ray crystallography