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Tsegay PS, Hernandez D, Brache C, Chatgilialoglu C, Krokidis MG, Chapagain P, Liu Y. Incorporation of 5',8-cyclo-2'deoxyadenosines by DNA repair polymerases via base excision repair. DNA Repair (Amst) 2022; 109:103258. [PMID: 34871863 PMCID: PMC9884144 DOI: 10.1016/j.dnarep.2021.103258] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 10/30/2021] [Accepted: 11/18/2021] [Indexed: 01/31/2023]
Abstract
5',8-cyclo-2-deoxy nucleosides (cdPus) are the smallest tandem purine lesions including 5',8-cyclo-2'-deoxyadenosine (cdA) and 5',8-cyclo-2'-deoxyguanosine (cdG). They can inhibit DNA and RNA polymerases causing mutations, DNA strand breaks, and termination of DNA replication and gene transcription. cdPus can be removed by nucleotide excision repair with low efficiency allowing them to accumulate in the genome. Recent studies suggest that cdPus can be induced in damaged nucleotide pools and incorporated into the genome by DNA polymerases. However, it remains unknown if and how DNA polymerases can incorporate cdPus. In this study, we examined the incorporation of cdAs by human DNA repair polymerases, DNA polymerases β (pol β), and pol η during base excision repair. We then determined the efficiency of cdA incorporation by the polymerases using steady-state kinetics. We found that pol β and pol η incorporated cdAs opposite dT and dC with low efficiency, and incorporated cdAs were readily extended and ligated into duplex DNA. Using molecular docking analysis, we found that the 5',8-covalent bond in cdA disrupted its hydrogen bonding with a template base suggesting that the phosphodiester bond between the 3'-terminus nucleotide and the α-phosphate of cdATP were generated in the absence of hydrogen bonding. The enzyme kinetics analysis further suggests that pol β and pol η increased their substrate binding to facilitate the enzyme catalysis for cdA incorporation. Our study reveals unique mechanisms underlying the accumulation of cdPu lesions in the genome resulting from nucleotide incorporation by repair DNA polymerases.
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Affiliation(s)
- Pawlos S. Tsegay
- Biochemistry Ph.D. Program, Florida International University, Miami, FL, USA
| | - Daniela Hernandez
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA
| | - Christopher Brache
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA
| | | | - Marios G. Krokidis
- Institute of Nanoscience and Nanotechnology, N.C.S.R. “Demokritos,” 15341, Agia Paraskevi, Athens, Greece
| | - Prem Chapagain
- Department of Physics, Florida International University, Miami, FL, USA,Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA
| | - Yuan Liu
- Biochemistry Ph.D. Program, Florida International University, Miami, FL, USA,Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA,Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA,Correspondence:
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Karwowski BT. (5' S) 5',8-Cyclo-2'-Deoxyadenosine Cannot Stop BER. Clustered DNA Lesion Studies. Int J Mol Sci 2021; 22:ijms22115934. [PMID: 34072994 PMCID: PMC8199134 DOI: 10.3390/ijms22115934] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/28/2021] [Accepted: 05/29/2021] [Indexed: 12/12/2022] Open
Abstract
As a result of external and endocellular physical-chemical factors, every day approximately ~105 DNA lesions might be formed in each human cell. During evolution, living organisms have developed numerous repair systems, of which Base Excision Repair (BER) is the most common. 5′,8-cyclo-2′-deoxyadenosine (cdA) is a tandem lesion that is removed by the Nucleotide Excision Repair (NER) mechanism. Previously, it was assumed that BER machinery was not able to remove (5′S)cdA from the genome. In this study; however, it has been demonstrated that, if (5′S)cdA is a part of a single-stranded clustered DNA lesion, it can be removed from ds-DNA by BER. The above is theoretically possible in two cases: (A) When, during repair, clustered lesions form Okazaki-like fragments; or (B) when the (5′S)cdA moiety is located in the oligonucleotide strand on the 3′-end side of the adjacent DNA damage site, but not when it appears at the opposite 5′-end side. To explain this phenomenon, pure enzymes involved in BER were used (polymerase β (Polβ), a Proliferating Cell Nuclear Antigen (PCNA), and the X-Ray Repair Cross-Complementing Protein 1 (XRCC1)), as well as the Nuclear Extract (NE) from xrs5 cells. It has been found that Polβ can effectively elongate the primer strand in the presence of XRCC1 or PCNA. Moreover, supplementation of the NE from xrs5 cells with Polβ (artificial Polβ overexpression) forced oligonucleotide repair via BER in all the discussed cases.
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Affiliation(s)
- Boleslaw T Karwowski
- DNA Damage Laboratory of Food Science Department, Faculty of Pharmacy, Medical University of Lodz, ul. Muszynskiego 1, 90-151 Lodz, Poland
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