title: The structure of the XPF-ssDNA complex underscores the distinct roles of the XPF and ERCC1 helix- hairpin-helix domains in ss/ds DNA recognition.
abstract: Human XPF/ERCC1 is a structure-specific DNA endonuclease that nicks the damaged DNA strand at the 5' end during nucleotide excision repair. We determined the structure of the complex of the C-terminal domain of XPF with 10 nt ssDNA. A positively charged region within the second helix of the first HhH motif contacts the ssDNA phosphate backbone. One guanine base is flipped out of register and positioned in a pocket contacting residues from both HhH motifs of XPF. Comparison to other HhH-containing proteins indicates a one-residue deletion in the second HhH motif of XPF that has altered the hairpin conformation, thereby permitting ssDNA interactions. Previous nuclear magnetic resonance studies showed that ERCC1 in the XPF-ERCC1 heterodimer can bind dsDNA. Combining the two observations gives a model that underscores the asymmetry of the human XPF/ERCC1 heterodimer in binding at an ss/ds DNA junction.
authors.affiliation: Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Devashish
authors.initials: D
authors.lastname: Das
authors.forename: Gert E
authors.initials: GE
authors.lastname: Folkers
authors.forename: Marc
authors.initials: M
authors.lastname: van Dijk
authors.forename: Nicolaas G J
authors.initials: NG
authors.lastname: Jaspers
authors.forename: Jan H J
authors.initials: JH
authors.lastname: Hoeijmakers
authors.forename: Robert
authors.initials: R
authors.lastname: Kaptein
authors.forename: Rolf
authors.initials: R
authors.lastname: Boelens
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D004720:Endonucleases / Q000737:chemistry* / Q000235:genetics; D006147:Guanine / Q000737:chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055672:Static Electricity
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; C095888:xeroderma pigmentosum group F protein; D006147:Guanine; D004247:DNA; C071447:ERCC1 protein, human; D004720:Endonucleases