Structural and thermodynamic insight into escherichia coli uvrabc-mediated incision of cluster diacetylaminofluorene adducts on the nar i sequence

Vipin Jain, Benjamin Hilton, Bin Lin, Anshu Jain, Alexander D. Mackerell, Yue Zou, Bongsup P. Cho

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Cluster DNA damage refers to two or more lesions in a single turn of the DNA helix. Such clustering may occur with bulky DNA lesions, which may be responsible for their sequence-dependent repair and mutational outcomes. Here we prepared three 16-mer cluster duplexes in which two fluoroacetylaminofluorene adducts (dG-FAAF) are separated by zero, one, and two nucleotides in the Escherichia coli NarI mutational hot spot (5′-CTCTCG1G 2CG3CCATCAC-3′): 5′-CG1* G2*CG3CC-3′, 5′-CG1G 2*CG3*CC-3′, and 5′-CG 1*G2CG3*CC-3′ (G* = dG-FAAF), respectively. We conducted spectroscopic, thermodynamic, and molecular dynamics studies of these di-FAAF duplexes, and the results were compared with those of the corresponding mono-FAAF adducts in the same NarI sequence [Jain, V., et al. (2012) Nucleic Acids Res. 40, 3939-3951]. Our nucleotide excision repair results showed the diadducts were more reparable than the corresponding monoadducts. Moreover, we observed dramatic flanking base sequence effects on their repair efficiency in the following order: NarI-G2G3 > NarI-G1G3 > NarI-G1G2. The nuclear magnetic resonance, circular dichroism, ultraviolet melting, and molecular dynamics simulation results revealed that in contrast to the monoadducts, diadducts produced a synergistic effect on duplex destabilization. In addition, dG-FAAF at G2G3 and G1G 3 destacks the neighboring bases, with greater destabilization occurring with the former. Overall, the results indicate the importance of base stacking and related thermal and thermodynamic destabilization in the repair of bulky cluster arylamine DNA adducts.

Original languageEnglish (US)
Pages (from-to)1251-1262
Number of pages12
JournalChemical research in toxicology
Volume26
Issue number8
DOIs
StatePublished - Aug 19 2013
Externally publishedYes

Fingerprint Dive into the research topics of 'Structural and thermodynamic insight into escherichia coli uvrabc-mediated incision of cluster diacetylaminofluorene adducts on the nar i sequence'. Together they form a unique fingerprint.

Cite this