Document Type
Article
Publication Date
1-1-2014
Description
XPA (xeroderma pigmentosum group A) protein is an essential factor for NER (nucleotide excision repair) which is believed to be involved in DNA damage recognition/verification, NER factor recruiting and stabilization of repair intermediates. Past studies on the structure of XPA have focused primarily on XPA interaction with damaged DNA. However, how XPA interacts with other DNA structures remains unknown though recent evidence suggest that these structures could be important for its roles in both NER and non-NER activities. Previously, we reported that XPA recognizes undamaged DNA ds/ssDNA (double-strand/single-strandDNA) junctions with a binding affinity much higher than its ability to bind bulky DNA damage. To understand how this interaction occurs biochemically we implemented a structural determination of the interaction using a MS-based protein footprinting method and limited proteolysis. By monitoring surface accessibility of XPA lysines to NHS-biotin modification in the free protein and the DNA junction-bound complex we show that XPA physically interacts with the DNA junctions via two lysines, K168 and K179, located in the previously known XPA(98-219) DBD (DNA-binding domain). Importantly, we also uncovered new lysine residues, outside of the known DBD, involved in the binding. We found that residues K221, K222, K224 and K236 in the C-terminal domain are involved in DNA binding. Limited proteolysis analysis of XPA-DNA interactions further confirmed this observation. Structural modelling with these data suggests a clamp-like DBD for the XPA binding to ds/ssDNA junctions. Our results provide a novel structure-function view of XPA-DNA junction interactions.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Citation Information
Hilton, Benjamin; Shkriabai, Nick; Musich, Phillip R.; Kvaratskhelia, Mamuka; Shell, Steven; and Zou, Yue. 2014. A New Structural Insight Into XPA-DNA Interactions. Bioscience Reports. Vol.34(6). 831-840. https://doi.org/10.1042/BSR20140158 PMID: 25385088 ISSN: 0144-8463
Copyright Statement
⃝c 2014 The Author(s) This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC-BY) (http://creativecommons.org/licenses/by/3.0/) 831 which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited.