6sxb
From Proteopedia
XPF-ERCC1 Cryo-EM Structure, DNA-Bound form
Structural highlights
Disease[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.[1] [2] [3] 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.[4] [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.[5] Function[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.[6] [ERCC1_HUMAN] Structure-specific DNA repair endonuclease responsible for the 5'-incision during DNA repair. Publication Abstract from PubMedThe structure-specific endonuclease XPF-ERCC1 participates in multiple DNA damage repair pathways including nucleotide excision repair (NER) and inter-strand crosslink repair (ICLR). How XPF-ERCC1 is catalytically activated by DNA junction substrates is not currently understood. Here we report cryo-electron microscopy structures of both DNA-free and DNA-bound human XPF-ERCC1. DNA-free XPF-ERCC1 adopts an auto-inhibited conformation in which the XPF helical domain masks the ERCC1 (HhH)2 domain and restricts access to the XPF catalytic site. DNA junction engagement releases the ERCC1 (HhH)2 domain to couple with the XPF-ERCC1 nuclease/nuclease-like domains. Structure-function data indicate xeroderma pigmentosum patient mutations frequently compromise the structural integrity of XPF-ERCC1. Fanconi anaemia patient mutations in XPF often display substantial in-vitro activity but are resistant to activation by ICLR recruitment factor SLX4. Our data provide insights into XPF-ERCC1 architecture and catalytic activation. Cryo-EM structures of the XPF-ERCC1 endonuclease reveal how DNA-junction engagement disrupts an auto-inhibited conformation.,Jones M, Beuron F, Borg A, Nans A, Earl CP, Briggs DC, Snijders AP, Bowles M, Morris EP, Linch M, McDonald NQ Nat Commun. 2020 Feb 28;11(1):1120. doi: 10.1038/s41467-020-14856-2. PMID:32111838[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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