Single molecule analysis reveals monomeric XPA bends DNA and undergoes episodic linear diffusion during damage search
| Autor: | Nina Simon, Florian Sauer, Bennett Van Houten, Thomas Carell, Isadora Carnaval Detweiler, Emily C. Beckwitt, Johanna Bretzler, Jochen Kuper, Caroline Kisker, Sunbok Jang, Simon C. Watkins |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
endocrine system DNA Repair Ultraviolet Rays DNA damage Science Biophysics General Physics and Astronomy Plasma protein binding Microscopy Atomic Force Article General Biochemistry Genetics and Molecular Biology Adduct Atomic force microscopy 03 medical and health sciences chemistry.chemical_compound Single-molecule biophysics Humans Molecule lcsh:Science Multidisciplinary 030102 biochemistry & molecular biology DNA adducts DNA General Chemistry Molecular biophysics Single-molecule experiment Single Molecule Imaging Xeroderma Pigmentosum Group A Protein DNA-Binding Proteins Nucleotide excision repair 030104 developmental biology Monomer chemistry lcsh:Q DNA Damage Protein Binding |
| Zdroj: | Nature Communications, Vol 11, Iss 1, Pp 1-14 (2020) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | Nucleotide excision repair (NER) removes a wide range of DNA lesions, including UV-induced photoproducts and bulky base adducts. XPA is an essential protein in eukaryotic NER, although reports about its stoichiometry and role in damage recognition are controversial. Here, by PeakForce Tapping atomic force microscopy, we show that human XPA binds and bends DNA by ∼60° as a monomer. Furthermore, we observe XPA specificity for the helix-distorting base adduct N-(2’-deoxyguanosin-8-yl)-2-acetylaminofluorene over non-damaged dsDNA. Moreover, single molecule fluorescence microscopy reveals that DNA-bound XPA exhibits multiple modes of linear diffusion between paused phases. The presence of DNA damage increases the frequency of pausing. Truncated XPA, lacking the intrinsically disordered N- and C-termini, loses specificity for DNA lesions and shows less pausing on damaged DNA. Our data are consistent with a working model in which monomeric XPA bends DNA, displays episodic phases of linear diffusion along DNA, and pauses in response to DNA damage. It is not fully understood how XPA interacts with a DNA lesion during nucleotide excision repair. Here, the authors use single molecule analysis to study XPA–DNA interactions, including the DNA bend angle, protein stoichiometry, and diffusive properties during damage search. |
| Databáze: | OpenAIRE |
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