Crystal Structure of the Complex between the C-Terminal Domains of Human XPF and ERCC1
[XPF_HUMAN] Defects in ERCC4 are the cause of xeroderma pigmentosum complementation group F (XP-F) [MIM:278760]; also known as xeroderma pigmentosum VI (XP6). XP-F is an autosomal recessive disease characterized by hypersensitivity of the skin to sunlight followed by high incidence of skin cancer and frequent neurologic abnormalities.   Defects in ERCC4 are a cause of XFE progeroid syndrome (XFEPS) [MIM:610965]. This syndrome is illustrated by one patient who presented with dwarfism, cachexia and microcephaly. [ERCC1_HUMAN] Defects in ERCC1 are the cause of cerebro-oculo-facio-skeletal syndrome type 4 (COFS4) [MIM:610758]. COFS is a degenerative autosomal recessive disorder of prenatal onset affecting the brain, eye and spinal cord. After birth, it leads to brain atrophy, hypoplasia of the corpus callosum, hypotonia, cataracts, microcornea, optic atrophy, progressive joint contractures and growth failure. Facial dysmorphism is a constant feature. Abnormalities of the skull, eyes, limbs, heart and kidney also occur.
[XPF_HUMAN] Structure-specific DNA repair endonuclease responsible for the 5-prime incision during DNA repair. Involved in homologous recombination that assists in removing interstrand cross-link. [ERCC1_HUMAN] Structure-specific DNA repair endonuclease responsible for the 5'-incision during DNA repair.
Publication Abstract from PubMed
Human XPF-ERCC1 is a DNA endonuclease that incises a damaged DNA strand on the 5' side of a lesion during nucleotide excision repair and has additional role(s) in homologous recombination and DNA interstrand crosslink repair. We show that a truncated form of XPF lacking the N-terminal helicase-like domain in complex with ERCC1 exhibits a structure-specific endonuclease activity with similar specificity to that of full-length XPF-ERCC1. Two domains of ERCC1, a central domain and a C-terminal tandem helix-hairpin-helix (HhH2) dimerization domain, bind to ssDNA. The central domain of ERCC1 binds ssDNA/dsDNA junctions with a defined polarity, preferring a 5' single-stranded overhang. The XPF-ERCC1 HhH2 domain heterodimer contains two independent ssDNA-binding surfaces, which are revealed by a crystal structure of the protein complex. A crystal structure of the central domain of ERCC1 shows its fold is strikingly similar to that of the nuclease domains of the archaeal Mus81/XPF homologs, despite very low sequence homology. A groove lined with basic and aromatic residues on the surface of ERCC1 has apparently been adapted to interact with ssDNA. On the basis of these crystallographic and biochemical studies, we propose a model in which XPF-ERCC1 recognizes a branched DNA substrate by binding the two ssDNA arms with the two HhH2 domains of XPF and ERCC1 and by binding the 5'-ssDNA arm with the central domain of ERCC1.
Crystal structure and DNA binding functions of ERCC1, a subunit of the DNA structure-specific endonuclease XPF-ERCC1.,Tsodikov OV, Enzlin JH, Scharer OD, Ellenberger T Proc Natl Acad Sci U S A. 2005 Aug 9;102(32):11236-41. Epub 2005 Aug 2. PMID:16076955
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.