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|1d4u, 1 NMR models ()|
INTERACTIONS OF HUMAN NUCLEOTIDE EXCISION REPAIR PROTEIN XPA WITH RPA70 AND DNA: CHEMICAL SHIFT MAPPING AND 15N NMR RELAXATION STUDIES
Human XPA is an essential component in the multienzyme nucleotide excision repair (NER) pathway. The solution structure of the minimal DNA binding domain of XPA (XPA-MBD: M98-F219) was recently determined [Buchko et al. (1998) Nucleic Acids Res. 26, 2779-2788, Ikegami et al. (1998) Nat. Struct. Biol. 5, 701-706] and shown to consist of a compact zinc-binding core and a loop-rich C-terminal subdomain connected by a linker sequence. Here, the solution structure of XPA-MBD was further refined using an entirely new class of restraints based on pseudocontact shifts measured in cobalt-substituted XPA-MBD. Using this structure, the surface of XPA-MBD which interacts with DNA and a fragment of the largest subunit of replication protein A (RPA70 Delta C327: M1-Y326) was determined using chemical shift mapping. DNA binding in XPA-MBD was highly localized in the loop-rich subdomain for DNA with or without a lesion [dihydrothymidine (dhT) or 6-4-thymidine-cytidine (64TC)], or with DNA in single- or double-stranded form, indicating that the character of the lesion itself is not the driving force for XPA binding DNA. RPA70 Delta C327 was found to contact regions in both the zinc-binding and loop-rich subdomains. Some overlap of the DNA and RPA70 Delta C327 binding regions was observed in the loop-rich subdomain, indicating a possible cooperative DNA-binding mode between XPA and RPA70 Delta C327. To complement the chemical shift mapping data, the backbone dynamics of free XPA-MBD and XPA-MBD bound to DNA oligomers containing dhT or 64TC lesions were investigated using 15N NMR relaxation data. The dynamic analyses for the XPA-MBD complexes with DNA revealed localized increases and decreases in S2 and an increase in the global correlation time. Regions of XPA-MBD with the largest increases in S2 overlapped regions having the largest chemical shifts changes upon binding DNA, indicating that the loop-rich subdomain becomes more rigid upon binding DNA. Interestingly, S2 decreased for some residues in the zinc-binding core upon DNA association, indicating a possible concerted structural rearrangement on binding DNA.
Interactions of human nucleotide excision repair protein XPA with DNA and RPA70 Delta C327: chemical shift mapping and 15N NMR relaxation studies., Buchko GW, Daughdrill GW, de Lorimier R, Rao B K, Isern NG, Lingbeck JM, Taylor JS, Wold MS, Gochin M, Spicer LD, Lowry DF, Kennedy MA, Biochemistry. 1999 Nov 16;38(46):15116-28. PMID:10563794
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[XPA_HUMAN] Defects in XPA are a cause of xeroderma pigmentosum complementation group A (XP-A) [MIM:278700]; also known as xeroderma pigmentosum type 1 (XP1). XP-A is a rare human autosomal recessive disease characterized by solar sensitivity, high predisposition for developing cancers on areas exposed to sunlight and, in some cases, neurological abnormalities. Group A patients show the most severe skin symptoms and progressive neurological disorders.
[XPA_HUMAN] Involved in DNA excision repair. Initiates repair by binding to damaged sites with various affinities, depending on the photoproduct and the transcriptional state of the region. Required for UV-induced CHEK1 phosphorylation and the recruitment of CEP164 to cyclobutane pyrimidine dimmers (CPD), sites of DNA damage after UV irradiation.
About this Structure
- Buchko GW, Daughdrill GW, de Lorimier R, Rao B K, Isern NG, Lingbeck JM, Taylor JS, Wold MS, Gochin M, Spicer LD, Lowry DF, Kennedy MA. Interactions of human nucleotide excision repair protein XPA with DNA and RPA70 Delta C327: chemical shift mapping and 15N NMR relaxation studies. Biochemistry. 1999 Nov 16;38(46):15116-28. PMID:10563794
- ↑ Satokata I, Tanaka K, Okada Y. Molecular basis of group A xeroderma pigmentosum: a missense mutation and two deletions located in a zinc finger consensus sequence of the XPAC gene. Hum Genet. 1992 Mar;88(6):603-7. PMID:1339397
- ↑ Satokata I, Tanaka K, Yuba S, Okada Y. Identification of splicing mutations of the last nucleotides of exons, a nonsense mutation, and a missense mutation of the XPAC gene as causes of group A xeroderma pigmentosum. Mutat Res. 1992 Mar;273(2):203-12. PMID:1372103
- ↑ States JC, McDuffie ER, Myrand SP, McDowell M, Cleaver JE. Distribution of mutations in the human xeroderma pigmentosum group A gene and their relationships to the functional regions of the DNA damage recognition protein. Hum Mutat. 1998;12(2):103-13. PMID:9671271 doi:<103::AID-HUMU5>3.0.CO;2-6 10.1002/(SICI)1098-1004(1998)12:2<103::AID-HUMU5>3.0.CO;2-6
- ↑ Pan YR, Lee EY. UV-dependent interaction between Cep164 and XPA mediates localization of Cep164 at sites of DNA damage and UV sensitivity. Cell Cycle. 2009 Feb 15;8(4):655-64. Epub 2009 Feb 14. PMID:19197159