Structural and biochemical impact of C8-aryl-guanine adducts within the Narl recognition DNA sequence: influence of aryl ring size on targeted and semi-targeted mutagenicity
Verwey, Anne M. R.
Rankin, Katherine M.
Witham, Aaron A.
Soldatov, Dmitriy V.
Manderville, Richard A.
Fekry, Mostafa I.
Sturla, Shana J.
Wetmore, Stacey D.
Oxford University Press
Chemical mutagens with an aromatic ring system may be enzymatically transformed to afford aryl radical species that preferentially react at the C8-site of 2 -deoxyguanosine (dG). The resulting carbonlinked C8-aryl-dG adduct possesses altered biophysical and genetic coding properties compared to the precursor nucleoside. Described herein are structural and in vitro mutagenicity studies of a series of fluorescent C8-aryl-dG analogues that differ in aryl ring size and are representative of authentic DNA adducts. These structural mimics have been inserted into a hotspot sequence for frameshift mutations, namely, the reiterated G3-position of the NarI sequence within 12mer (NarI(12)) and 22mer (NarI(22)) oligonucleotides. In the NarI(12) duplexes, the C8- aryl-dG adducts display a preference for adopting an anti-conformation opposite C, despite the strong syn preference of the free nucleoside. Using the NarI(22) sequence as a template for DNA synthesis in vitro, mutagenicity of the C8-aryl-dG adducts was assayed with representative high-fidelity replicative versus lesion bypass Y-family DNA polymerases, namely, Escherichia coli pol I Klenow fragment exo− (Kf−) and Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4). Our experiments provide a basis for a model involving a two-base slippage and subsequent realignment process to relate the miscoding properties of C-linked C8-aryl-dG adducts with their chemical structures.
Sherpa Romeo green journal, open access
DNA , C8-aryl-dG adducts , NarI , Mutagenicity
Sproviero, M., Verwey, A. M. R., Rankin, K. M., Witham, A. A., Soldatov, D. V., Manderville, R. A. ... & Wetmore, S. D. (2014). Structural and biochemical impact of C8-aryl-guanine adducts within the NarI recognition of DNA sequence: influence of aryl ring size on targeted and semi-targeted mutagenicity. Nucleic Acids Research, 42(21), 13405-13421. doi:10.1093/nar/gku1093