Error-Free Bypass of 7,8-dihydro-8-oxo-2′-deoxyguanosine by DNA Polymerase of Pseudomonas aeruginosa Phage PaP1
| Autor: | Wanneng Wang, Qizhen Xue, Shiling Gu, Huidong Zhang, Mei Xiong, Qin Liu |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Exonuclease lcsh:QH426-470 DNA polymerase Base pair 8-oxoG 03 medical and health sciences chemistry.chemical_compound steady-state kinetics Genetics P. aeruginosa phage PaP1 pre-steady-state kinetics nucleotide incorporation heterocyclic compounds Nucleotide Ternary complex Genetics (clinical) chemistry.chemical_classification biology Mutagenesis DNA replication Molecular biology lcsh:Genetics 030104 developmental biology Biochemistry chemistry biology.protein Erratum DNA |
| Zdroj: | Genes Genes; Volume 8; Issue 1; Pages: 18 Genes, Vol 8, Iss 1, p 18 (2017) |
| ISSN: | 2073-4425 |
| DOI: | 10.3390/genes8010018 |
| Popis: | As one of the most common forms of oxidative DNA damage, 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxoG) generally leads to G:C to T:A mutagenesis. To study DNA replication encountering 8-oxoG by the sole DNA polymerase (Gp90) of Pseudomonas aeruginosa phage PaP1, we performed steady-state and pre-steady-state kinetic analyses of nucleotide incorporation opposite 8-oxoG by Gp90 D234A that lacks exonuclease activities on ssDNA and dsDNA substrates. Gp90 D234A could bypass 8-oxoG in an error-free manner, preferentially incorporate dCTP opposite 8-oxoG, and yield similar misincorporation frequency to unmodified G. Gp90 D234A could extend beyond C:8-oxoG or A:8-oxoG base pairs with the same efficiency. dCTP incorporation opposite G and dCTP or dATP incorporation opposite 8-oxoG showed fast burst phases. The burst of incorporation efficiency (kpol/Kd,dNTP) is decreased as dCTP:G > dCTP:8-oxoG > dATP:8-oxoG. The presence of 8-oxoG in DNA does not affect its binding to Gp90 D234A in a binary complex but it does affect it in a ternary complex with dNTP and Mg2+, and dATP misincorporation opposite 8-oxoG further weakens the binding of Gp90 D234A to DNA. This study reveals Gp90 D234A can bypass 8-oxoG in an error-free manner, providing further understanding in DNA replication encountering oxidation lesion for P.aeruginosa phage PaP1. |
| Databáze: | OpenAIRE |
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