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Structural Insights on the Pamoic Acid and the 8 KDa Domain of DNA Polymerase Beta Complex: Towards the Design of Higher-affinity Inhibitors

Overview
Journal BMC Struct Biol
Publisher Biomed Central
Date 2008 Apr 18
PMID 18416825
Citations 6
Authors
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Abstract

Background: DNA polymerase beta (pol beta), the error-prone DNA polymerase of single-stranded DNA break repair as well as base excision repair pathways, is overexpressed in several tumors and takes part in chemotherapeutic agent resistance, like that of cisplatin, through translesion synthesis. For this reason pol beta has become a therapeutic target. Several inhibitors have been identified, but none of them presents a sufficient affinity and specificity to become a drug. The fragment-based inhibitor design allows an important improvement in affinity of small molecules. The initial and critical step for setting up the fragment-based strategy consists in the identification and structural characterization of the first fragment bound to the target.

Results: We have performed docking studies of pamoic acid, a 9 micromolar pol beta inhibitor, and found that it binds in a single pocket at the surface of the 8 kDa domain of pol beta. However, docking studies provided five possible conformations for pamoic acid in this site. NMR experiments were performed on the complex to select a single conformation among the five retained. Chemical Shift Mapping data confirmed pamoic acid binding site found by docking while NOESY and saturation transfer experiments provided distances between pairs of protons from the pamoic acid and those of the 8 kDa domain that allowed the identification of the correct conformation.

Conclusion: Combining NMR experiments on the complex with docking results allowed us to build a three-dimensional structural model. This model serves as the starting point for further structural studies aimed at improving the affinity of pamoic acid for binding to DNA polymerase beta.

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References
1.
Mizushina Y, Tanaka N, Kitamura A, Tamai K, Ikeda M, Takemura M . The inhibitory effect of novel triterpenoid compounds, fomitellic acids, on DNA polymerase beta. Biochem J. 1998; 330 ( Pt 3):1325-32. PMC: 1219279. DOI: 10.1042/bj3301325. View

2.
Prasad R, Beard W, Chyan J, Maciejewski M, Mullen G, Wilson S . Functional analysis of the amino-terminal 8-kDa domain of DNA polymerase beta as revealed by site-directed mutagenesis. DNA binding and 5'-deoxyribose phosphate lyase activities. J Biol Chem. 1998; 273(18):11121-6. DOI: 10.1074/jbc.273.18.11121. View

3.
Wilson S, Sobol R, Beard W, Horton J, Prasad R, Vande Berg B . DNA polymerase beta and mammalian base excision repair. Cold Spring Harb Symp Quant Biol. 2003; 65:143-55. DOI: 10.1101/sqb.2000.65.143. View

4.
Johnson B . Using NMRView to visualize and analyze the NMR spectra of macromolecules. Methods Mol Biol. 2004; 278:313-52. DOI: 10.1385/1-59259-809-9:313. View

5.
Liu D, Prasad R, Wilson S, DeRose E, Mullen G . Three-dimensional solution structure of the N-terminal domain of DNA polymerase beta and mapping of the ssDNA interaction interface. Biochemistry. 1996; 35(20):6188-200. DOI: 10.1021/bi952656o. View