1. Single-stranded DNA mimicry in the p53 transactivation domain interaction with replication protein A.
- Author
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Bochkareva, Elena, Kaustov, Lilia, Ayed, Ayeda, Gwan-Su Yi, Ying Lu, Pineda-Lucena, Antonio, Liao, Jack C. C., Okorokov, Andrei L., Milner, Jo, Arrowsmith, Cheryl H., and Bochkarev, Alexey
- Subjects
PROTEINS ,CARRIER proteins ,BIOCHEMICAL genetics ,GENES ,DNA damage ,GENETIC mutation - Abstract
One of many protein-protein interactions modulated upon DNA damage is that of the single-stranded DNA-binding protein, replication protein A (RPA), with the p53 tumor suppressor. Here we report the crystal structure of RPA residues 1-120 (RPA70N) bound to the N-terminal transactivation domain of p53 (residues 37-57; p53N) and, by using NMR spectroscopy, characterize two mechanisms by which the RPA/p53 interaction can be modulated. RPA70N forms an oligonucleotide/oligosaccharide-binding fold, similar to that previously observed for the ssDNA-binding domains of RPA. In contrast the N-terminal p53 transactivation domain is largely disordered in solution, but residues 37-57 fold into two amphipathic helices, H1 and H2, upon binding with RPA70N. The H2 helix of p53 structurally mimics the binding of ssDNA to the oligonucleotide/oligosaccharide-binding fold. NMR experiments confirmed that both ssDNA and an acidic peptide mimicking a phosphorylated form of RPA32N can independently compete the acidic pS3N out of the binding site. Taken together, our data suggest a mechanism for DNA damage signaling that can explain a threshold response to DNA damage. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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