1
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Kaminski AM, Chiruvella KK, Ramsden DA, Bebenek K, Kunkel TA, Pedersen LC. DNA polymerase λ Loop1 variant yields unexpected gain-of-function capabilities in nonhomologous end-joining. DNA Repair (Amst) 2024; 136:103645. [PMID: 38428373 PMCID: PMC11078337 DOI: 10.1016/j.dnarep.2024.103645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 03/03/2024]
Abstract
DNA polymerases lambda (Polλ) and mu (Polμ) are X-Family polymerases that participate in DNA double-strand break (DSB) repair by the nonhomologous end-joining pathway (NHEJ). Both polymerases direct synthesis from one DSB end, using template derived from a second DSB end. In this way, they promote the NHEJ ligation step and minimize the sequence loss normally associated with this pathway. The two polymerases differ in cognate substrate, as Polλ is preferred when synthesis must be primed from a base-paired DSB end, while Polμ is required when synthesis must be primed from an unpaired DSB end. We generated a Polλ variant (PolλKGET) that retained canonical Polλ activity on a paired end-albeit with reduced incorporation fidelity. We recently discovered that the variant had unexpectedly acquired the activity previously unique to Polμ-synthesis from an unpaired primer terminus. Though the sidechains of the Loop1 region make no contact with the DNA substrate, PolλKGET Loop1 amino acid sequence is surprisingly essential for its unique activity during NHEJ. Taken together, these results underscore that the Loop1 region plays distinct roles in different Family X polymerases.
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Affiliation(s)
- Andrea M Kaminski
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA
| | - Kishore K Chiruvella
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Katarzyna Bebenek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA.
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2
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Balint E, Unk I. For the Better or for the Worse? The Effect of Manganese on the Activity of Eukaryotic DNA Polymerases. Int J Mol Sci 2023; 25:363. [PMID: 38203535 PMCID: PMC10779026 DOI: 10.3390/ijms25010363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/12/2024] Open
Abstract
DNA polymerases constitute a versatile group of enzymes that not only perform the essential task of genome duplication but also participate in various genome maintenance pathways, such as base and nucleotide excision repair, non-homologous end-joining, homologous recombination, and translesion synthesis. Polymerases catalyze DNA synthesis via the stepwise addition of deoxynucleoside monophosphates to the 3' primer end in a partially double-stranded DNA. They require divalent metal cations coordinated by active site residues of the polymerase. Mg2+ is considered the likely physiological activator because of its high cellular concentration and ability to activate DNA polymerases universally. Mn2+ can also activate the known DNA polymerases, but in most cases, it causes a significant decrease in fidelity and/or processivity. Hence, Mn2+ has been considered mutagenic and irrelevant during normal cellular function. Intriguingly, a growing body of evidence indicates that Mn2+ can positively influence some DNA polymerases by conferring translesion synthesis activity or altering the substrate specificity. Here, we review the relevant literature focusing on the impact of Mn2+ on the biochemical activity of a selected set of polymerases, namely, Polβ, Polλ, and Polµ, of the X family, as well as Polι and Polη of the Y family of polymerases, where congruous data implicate the physiological relevance of Mn2+ in the cellular function of these enzymes.
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Affiliation(s)
| | - Ildiko Unk
- Institute of Genetics, HUN-REN Biological Research Centre Szeged, H-6726 Szeged, Hungary;
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3
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Qin T, Hu B, Zhao Q, Wang Y, Wang S, Luo D, Lyu J, Chen Y, Gan J, Huang Z. Structural Insight into Polymerase Mechanism via a Chiral Center Generated with a Single Selenium Atom. Int J Mol Sci 2023; 24:15758. [PMID: 37958741 PMCID: PMC10647396 DOI: 10.3390/ijms242115758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/19/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023] Open
Abstract
DNA synthesis catalyzed by DNA polymerase is essential for all life forms, and phosphodiester bond formation with phosphorus center inversion is a key step in this process. Herein, by using a single-selenium-atom-modified dNTP probe, we report a novel strategy to visualize the reaction stereochemistry and catalysis. We capture the before- and after-reaction states and provide explicit evidence of the center inversion and in-line attacking SN2 mechanism of DNA polymerization, while solving the diastereomer absolute configurations. Further, our kinetic and thermodynamic studies demonstrate that in the presence of Mg2+ ions (or Mn2+), the binding affinity (Km) and reaction selectivity (kcat/Km) of dGTPαSe-Rp were 51.1-fold (or 19.5-fold) stronger and 21.8-fold (or 11.3-fold) higher than those of dGTPαSe-Sp, respectively, indicating that the diastereomeric Se-Sp atom was quite disruptive of the binding and catalysis. Our findings reveal that the third metal ion is much more critical than the other two metal ions in both substrate recognition and bond formation, providing insights into how to better design the polymerase inhibitors and discover the therapeutics.
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Affiliation(s)
- Tong Qin
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China; (T.Q.); (B.H.); (Q.Z.); (S.W.); (J.L.)
| | - Bei Hu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China; (T.Q.); (B.H.); (Q.Z.); (S.W.); (J.L.)
| | - Qianwei Zhao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China; (T.Q.); (B.H.); (Q.Z.); (S.W.); (J.L.)
- Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450000, China
| | - Yali Wang
- College of Bioengineering, Sichuan University of Science and Engineering, Yibin 644000, China;
| | - Shaoxin Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China; (T.Q.); (B.H.); (Q.Z.); (S.W.); (J.L.)
| | - Danyan Luo
- SeNA Research Institute and Szostak-CDHT Large Nucleic Acid Institute, Chengdu 618000, China;
| | - Jiazhen Lyu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China; (T.Q.); (B.H.); (Q.Z.); (S.W.); (J.L.)
| | - Yiqing Chen
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China;
| | - Jianhua Gan
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China;
| | - Zhen Huang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China; (T.Q.); (B.H.); (Q.Z.); (S.W.); (J.L.)
- SeNA Research Institute and Szostak-CDHT Large Nucleic Acid Institute, Chengdu 618000, China;
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 610000, China
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4
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Vogt A, He Y. Structure and mechanism in non-homologous end joining. DNA Repair (Amst) 2023; 130:103547. [PMID: 37556875 PMCID: PMC10528545 DOI: 10.1016/j.dnarep.2023.103547] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/11/2023]
Abstract
DNA double-stranded breaks (DSBs) are a particularly challenging form of DNA damage to repair because the damaged DNA must not only undergo the chemical reactions responsible for returning it to its original state, but, additionally, the two free ends can become physically separated in the nucleus and must be bridged prior to repair. In nonhomologous end joining (NHEJ), one of the major pathways of DSB repair, repair is carried out by a number of repair factors capable of binding to and directly joining DNA ends. It has been unclear how these processes are carried out at a molecular level, owing in part to the lack of structural evidence describing the coordination of the NHEJ factors with each other and a DNA substrate. Advances in cryo-Electron Microscopy (cryo-EM), allowing for the structural characterization of large protein complexes that would be intractable using other techniques, have led to the visualization several key steps of the NHEJ process, which support a model of sequential assembly of repair factors at the DSB, followed by end-bridging mediated by protein-protein complexes and transition to full synapsis. Here we examine the structural evidence for these models, devoting particular attention to recent work identifying a new NHEJ intermediate state and incorporating new NHEJ factors into the general mechanism. We also discuss the evolving understanding of end-bridging mechanisms in NHEJ and DNA-PKcs's role in mediating DSB repair.
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Affiliation(s)
- Alex Vogt
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, USA
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA; Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, USA.
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5
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Kaminski AM, Chiruvella KK, Ramsden DA, Bebenek K, Kunkel TA, Pedersen LC. Analysis of diverse double-strand break synapsis with Polλ reveals basis for unique substrate specificity in nonhomologous end-joining. Nat Commun 2022; 13:3806. [PMID: 35778389 PMCID: PMC9249759 DOI: 10.1038/s41467-022-31278-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 06/10/2022] [Indexed: 01/02/2023] Open
Abstract
DNA double-strand breaks (DSBs) threaten genomic stability, since their persistence can lead to loss of critical genetic information, chromosomal translocations or rearrangements, and cell death. DSBs can be repaired through the nonhomologous end-joining pathway (NHEJ), which processes and ligates DNA ends efficiently to prevent or minimize sequence loss. Polymerase λ (Polλ), one of the Family X polymerases, fills sequence gaps of DSB substrates with a strict specificity for a base-paired primer terminus. There is little information regarding Polλ's approach to engaging such substrates. We used in vitro polymerization and cell-based NHEJ assays to explore the contributions of conserved loop regions toward DSB substrate specificity and utilization. In addition, we present multiple crystal structures of Polλ in synapsis with varying biologically relevant DSB end configurations, revealing how key structural features and hydrogen bonding networks work in concert to stabilize these tenuous, potentially cytotoxic DNA lesions during NHEJ.
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Affiliation(s)
- Andrea M Kaminski
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA
| | - Kishore K Chiruvella
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Katarzyna Bebenek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA.
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA
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6
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Jamsen JA, Shock DD, Wilson SH. Watching right and wrong nucleotide insertion captures hidden polymerase fidelity checkpoints. Nat Commun 2022; 13:3193. [PMID: 35680862 PMCID: PMC9184648 DOI: 10.1038/s41467-022-30141-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/19/2022] [Indexed: 12/26/2022] Open
Abstract
Efficient and accurate DNA synthesis is enabled by DNA polymerase fidelity checkpoints that promote insertion of the right instead of wrong nucleotide. Erroneous X-family polymerase (pol) λ nucleotide insertion leads to genomic instability in double strand break and base-excision repair. Here, time-lapse crystallography captures intermediate catalytic states of pol λ undergoing right and wrong natural nucleotide insertion. The revealed nucleotide sensing mechanism responds to base pair geometry through active site deformation to regulate global polymerase-substrate complex alignment in support of distinct optimal (right) or suboptimal (wrong) reaction pathways. An induced fit during wrong but not right insertion, and associated metal, substrate, side chain and pyrophosphate reaction dynamics modulated nucleotide insertion. A third active site metal hastened right but not wrong insertion and was not essential for DNA synthesis. The previously hidden fidelity checkpoints uncovered reveal fundamental strategies of polymerase DNA repair synthesis in genomic instability. DNA polymerase (pol) λ performs DNA synthesis in base excision and double strand break repair. How pol λ accomplishes nucleotide insertion that can lead to mutagenesis and genomic instability was unclear. Here the authors employ time-lapse crystallography to reveal hidden polymerase checkpoints that enable right and wrong natural nucleotide insertion by pol λ.
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Affiliation(s)
- Joonas A Jamsen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
| | - David D Shock
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
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7
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Structural and Molecular Kinetic Features of Activities of DNA Polymerases. Int J Mol Sci 2022; 23:ijms23126373. [PMID: 35742812 PMCID: PMC9224347 DOI: 10.3390/ijms23126373] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/01/2022] [Accepted: 06/06/2022] [Indexed: 02/01/2023] Open
Abstract
DNA polymerases catalyze DNA synthesis during the replication, repair, and recombination of DNA. Based on phylogenetic analysis and primary protein sequences, DNA polymerases have been categorized into seven families: A, B, C, D, X, Y, and RT. This review presents generalized data on the catalytic mechanism of action of DNA polymerases. The structural features of different DNA polymerase families are described in detail. The discussion highlights the kinetics and conformational dynamics of DNA polymerases from all known polymerase families during DNA synthesis.
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8
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Prostova M, Shilkin E, Kulikova AA, Makarova A, Ryazansky S, Kulbachinskiy A. Noncanonical prokaryotic X family DNA polymerases lack polymerase activity and act as exonucleases. Nucleic Acids Res 2022; 50:6398-6413. [PMID: 35657103 PMCID: PMC9226535 DOI: 10.1093/nar/gkac461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/12/2022] Open
Abstract
The X family polymerases (PolXs) are specialized DNA polymerases that are found in all domains of life. While the main representatives of eukaryotic PolXs, which have dedicated functions in DNA repair, were studied in much detail, the functions and diversity of prokaryotic PolXs have remained largely unexplored. Here, by combining a comprehensive bioinformatic analysis of prokaryotic PolXs and biochemical experiments involving selected recombinant enzymes, we reveal a previously unrecognized group of PolXs that seem to be lacking DNA polymerase activity. The noncanonical PolXs contain substitutions of the key catalytic residues and deletions in their polymerase and dNTP binding sites in the palm and fingers domains, but contain functional nuclease domains, similar to canonical PolXs. We demonstrate that representative noncanonical PolXs from the Deinococcus genus are indeed inactive as DNA polymerases but are highly efficient as 3'-5' exonucleases. We show that both canonical and noncanonical PolXs are often encoded together with the components of the non-homologous end joining pathway and may therefore participate in double-strand break repair, suggesting an evolutionary conservation of this PolX function. This is a remarkable example of polymerases that have lost their main polymerase activity, but retain accessory functions in DNA processing and repair.
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Affiliation(s)
| | - Evgeniy Shilkin
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, Moscow 123182, Russia
| | - Alexandra A Kulikova
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, Moscow 123182, Russia
| | - Alena Makarova
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, Moscow 123182, Russia
| | - Sergei Ryazansky
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, Moscow 123182, Russia
| | - Andrey Kulbachinskiy
- To whom correspondence should be addressed. Tel: +7 4991960015; Fax: +7 4991960015;
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9
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Rechkunova NI, Zhdanova PV, Lebedeva NA, Maltseva EA, Koval VV, Lavrik OI. Structural features of DNA polymerases β and λ in complex with benzo[a]pyrene-adducted DNA cause a difference in lesion tolerance. DNA Repair (Amst) 2022; 116:103353. [DOI: 10.1016/j.dnarep.2022.103353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 05/31/2022] [Indexed: 11/28/2022]
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10
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Oh JM, Myung K. Crosstalk between different DNA repair pathways for DNA double strand break repairs. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 873:503438. [PMID: 35094810 DOI: 10.1016/j.mrgentox.2021.503438] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/09/2021] [Accepted: 12/14/2021] [Indexed: 11/28/2022]
Abstract
DNA double strand breaks (DSBs) are the most threatening type of DNA lesions and must be repaired properly in order to inhibit severe diseases and cell death. There are four major repair pathways for DSBs: non-homologous end joining (NHEJ), homologous recombination (HR), single strand annealing (SSA) and alternative end joining (alt-EJ). Cells choose repair pathway depending on the cell cycle phase and the length of 3' end of the DNA when DSBs are generated. Blunt and short regions of the 5' or 3' overhang DNA are repaired by NHEJ, which uses direct ligation or limited resection processing of the broken DNA end. In contrast, HR, SSA and alt-EJ use the resected DNA generated by the MRN (MRE11-RAD50-NBS1) complex and C-terminal binding protein interacting protein (CtIP) activated during the S and G2 phases. Here, we review recent findings on each repair pathway and the choice of repair mechanism and highlight the role of mismatch repair (MMR) protein in HR.
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Affiliation(s)
- Jung-Min Oh
- Department of Oral Biochemistry, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan 50612, Republic of Korea.
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea; Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
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11
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Structural Insights into the Specificity of 8-Oxo-7,8-dihydro-2′-deoxyguanosine Bypass by Family X DNA Polymerases. Genes (Basel) 2021; 13:genes13010015. [PMID: 35052363 PMCID: PMC8774566 DOI: 10.3390/genes13010015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 11/23/2022] Open
Abstract
8-oxo-guanine (8OG) is a common base lesion, generated by reactive oxygen species, which has been associated with human diseases such as cancer, aging-related neurodegenerative disorders and atherosclerosis. 8OG is highly mutagenic, due to its dual-coding potential it can pair both with adenine or cytidine. Therefore, it creates a challenge for DNA polymerases striving to correctly replicate and/or repair genomic or mitochondrial DNA. Numerous structural studies provide insights into the mechanistic basis of the specificity of 8OG bypass by DNA polymerases from different families. Here, we focus on how repair polymerases from Family X (Pols β, λ and µ) engage DNA substrates containing the oxidized guanine. We review structures of binary and ternary complexes for the three polymerases, which represent distinct steps in their catalytic cycles—the binding of the DNA substrate and the incoming nucleotide, followed by its insertion and extension. At each of these steps, the polymerase may favor or exclude the correct C or incorrect A, affecting the final outcome, which varies depending on the enzyme.
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12
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Yoon JH, Basu D, Choudhury JR, Prakash S, Prakash L. DNA polymerase λ promotes error-free replication through Watson-Crick impairing N1-methyl-deoxyadenosine adduct in conjunction with DNA polymerase ζ. J Biol Chem 2021; 297:100868. [PMID: 34119520 PMCID: PMC8260881 DOI: 10.1016/j.jbc.2021.100868] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/06/2021] [Accepted: 06/09/2021] [Indexed: 11/26/2022] Open
Abstract
In a previous study, we showed that replication through the N1-methyl-deoxyadenosine (1-MeA) adduct in human cells is mediated via three different Polι/Polθ, Polη, and Polζ-dependent pathways. Based on biochemical studies with these Pols, in the Polι/Polθ pathway, we inferred a role for Polι in the insertion of a nucleotide (nt) opposite 1-MeA and of Polθ in extension of synthesis from the inserted nt; in the Polη pathway, we inferred that this Pol alone would replicate through 1-MeA; in the Polζ pathway, however, the Pol required for inserting an nt opposite 1-MeA had remained unidentified. In this study, we provide biochemical and genetic evidence for a role for Polλ in inserting the correct nt T opposite 1-MeA, from which Polζ would extend synthesis. The high proficiency of purified Polλ for inserting a T opposite 1-MeA implicates a role for Polλ—which normally uses W-C base pairing for DNA synthesis—in accommodating 1-MeA in a syn confirmation and forming a Hoogsteen base pair with T. The potential of Polλ to replicate through DNA lesions by Hoogsteen base pairing adds another novel aspect to Polλ’s role in translesion synthesis in addition to its role as a scaffolding component of Polζ. We discuss how the action mechanisms of Polλ and Polζ could be restrained to inserting a T opposite 1-MeA and extending synthesis thereafter, respectively.
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Affiliation(s)
- Jung-Hoon Yoon
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Debashree Basu
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jayati Roy Choudhury
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Satya Prakash
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Louise Prakash
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA.
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13
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Jamsen JA, Sassa A, Shock DD, Beard WA, Wilson SH. Watching a double strand break repair polymerase insert a pro-mutagenic oxidized nucleotide. Nat Commun 2021; 12:2059. [PMID: 33824325 PMCID: PMC8024293 DOI: 10.1038/s41467-021-21354-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 12/08/2020] [Indexed: 01/07/2023] Open
Abstract
Oxidized dGTP (8-oxo-7,8-dihydro-2´-deoxyguanosine triphosphate, 8-oxodGTP) insertion by DNA polymerases strongly promotes cancer and human disease. How DNA polymerases discriminate against oxidized and undamaged nucleotides, especially in error-prone double strand break (DSB) repair, is poorly understood. High-resolution time-lapse X-ray crystallography snapshots of DSB repair polymerase μ undergoing DNA synthesis reveal that a third active site metal promotes insertion of oxidized and undamaged dGTP in the canonical anti-conformation opposite template cytosine. The product metal bridged O8 with product oxygens, and was not observed in the syn-conformation opposite template adenine (At). Rotation of At into the syn-conformation enabled undamaged dGTP misinsertion. Exploiting metal and substrate dynamics in a rigid active site allows 8-oxodGTP to circumvent polymerase fidelity safeguards to promote pro-mutagenic double strand break repair.
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Affiliation(s)
- Joonas A. Jamsen
- grid.280664.e0000 0001 2110 5790Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 USA
| | - Akira Sassa
- grid.136304.30000 0004 0370 1101Laboratory of Chromatin Metabolism and Epigenetics, Graduate School of Science, Chiba University, Chiba, Japan
| | - David D. Shock
- grid.280664.e0000 0001 2110 5790Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 USA
| | - William A. Beard
- grid.280664.e0000 0001 2110 5790Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 USA
| | - Samuel H. Wilson
- grid.280664.e0000 0001 2110 5790Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 USA
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14
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Kaminski AM, Bebenek K, Pedersen LC, Kunkel TA. DNA polymerase mu: An inflexible scaffold for substrate flexibility. DNA Repair (Amst) 2021; 93:102932. [PMID: 33087269 DOI: 10.1016/j.dnarep.2020.102932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
DNA polymerase μ is a Family X member that participates in repair of DNA double strand breaks (DSBs) by non-homologous end joining. Its role is to fill short gaps arising as intermediates in the process of V(D)J recombination and during processing of accidental double strand breaks. Pol μ is the only known template-dependent polymerase that can repair non-complementary DSBs with unpaired 3´primer termini. Here we review the unique properties of Pol μ that allow it to productively engage such a highly unstable substrate to generate a nick that can be sealed by DNA Ligase IV.
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Affiliation(s)
- Andrea M Kaminski
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Katarzyna Bebenek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
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15
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Kaminski AM, Pryor JM, Ramsden DA, Kunkel TA, Pedersen LC, Bebenek K. Structural snapshots of human DNA polymerase μ engaged on a DNA double-strand break. Nat Commun 2020; 11:4784. [PMID: 32963245 PMCID: PMC7508851 DOI: 10.1038/s41467-020-18506-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 08/17/2020] [Indexed: 01/07/2023] Open
Abstract
Genomic integrity is threatened by cytotoxic DNA double-strand breaks (DSBs), which must be resolved efficiently to prevent sequence loss, chromosomal rearrangements/translocations, or cell death. Polymerase μ (Polμ) participates in DSB repair via the nonhomologous end-joining (NHEJ) pathway, by filling small sequence gaps in broken ends to create substrates ultimately ligatable by DNA Ligase IV. Here we present structures of human Polμ engaging a DSB substrate. Synapsis is mediated solely by Polμ, facilitated by single-nucleotide homology at the break site, wherein both ends of the discontinuous template strand are stabilized by a hydrogen bonding network. The active site in the quaternary Pol μ complex is poised for catalysis and nucleotide incoporation proceeds in crystallo. These structures demonstrate that Polμ may address complementary DSB substrates during NHEJ in a manner indistinguishable from single-strand breaks.
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Affiliation(s)
- Andrea M. Kaminski
- grid.94365.3d0000 0001 2297 5165Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101/Rm F338, Research Triangle Park, NC 27709 USA
| | - John M. Pryor
- grid.10698.360000000122483208Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, 32-046 Lineberger Comprehensive Cancer Center, 450 West Dr., CB 7295, Chapel Hill, NC 27599 USA
| | - Dale A. Ramsden
- grid.10698.360000000122483208Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, 32-046 Lineberger Comprehensive Cancer Center, 450 West Dr., CB 7295, Chapel Hill, NC 27599 USA
| | - Thomas A. Kunkel
- grid.94365.3d0000 0001 2297 5165Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101/Rm F338, Research Triangle Park, NC 27709 USA
| | - Lars C. Pedersen
- grid.94365.3d0000 0001 2297 5165Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101/Rm F338, Research Triangle Park, NC 27709 USA
| | - Katarzyna Bebenek
- grid.94365.3d0000 0001 2297 5165Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101/Rm F338, Research Triangle Park, NC 27709 USA
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16
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Abstract
Genomic DNA is susceptible to endogenous and environmental stresses that modify DNA structure and its coding potential. Correspondingly, cells have evolved intricate DNA repair systems to deter changes to their genetic material. Base excision DNA repair involves a number of enzymes and protein cofactors that hasten repair of damaged DNA bases. Recent advances have identified macromolecular complexes that assemble at the DNA lesion and mediate repair. The repair of base lesions generally requires five enzymatic activities: glycosylase, endonuclease, lyase, polymerase, and ligase. The protein cofactors and mechanisms for coordinating the sequential enzymatic steps of repair are being revealed through a range of experimental approaches. We discuss the enzymes and protein cofactors involved in eukaryotic base excision repair, emphasizing the challenge of integrating findings from multiple methodologies. The results provide an opportunity to assimilate biochemical findings with cell-based assays to uncover new insights into this deceptively complex repair pathway.
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Affiliation(s)
- William A Beard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
| | - Julie K Horton
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
| | - Rajendra Prasad
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
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17
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Smith MR, Shock DD, Beard WA, Greenberg MM, Freudenthal BD, Wilson SH. A guardian residue hinders insertion of a Fapy•dGTP analog by modulating the open-closed DNA polymerase transition. Nucleic Acids Res 2019; 47:3197-3207. [PMID: 30649431 PMCID: PMC6451102 DOI: 10.1093/nar/gkz002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 12/17/2018] [Accepted: 01/03/2019] [Indexed: 01/07/2023] Open
Abstract
4,6-Diamino-5-formamidopyrimidine (Fapy•dG) is an abundant form of oxidative DNA damage that is mutagenic and contributes to the pathogenesis of human disease. When Fapy•dG is in its nucleotide triphosphate form, Fapy•dGTP, it is inefficiently cleansed from the nucleotide pool by the responsible enzyme in Escherichia coli MutT and its mammalian homolog MTH1. Therefore, under oxidative stress conditions, Fapy•dGTP could become a pro-mutagenic substrate for insertion into the genome by DNA polymerases. Here, we evaluated insertion kinetics and high-resolution ternary complex crystal structures of a configurationally stable Fapy•dGTP analog, β-C-Fapy•dGTP, with DNA polymerase β. The crystallographic snapshots and kinetic data indicate that binding of β-C-Fapy•dGTP impedes enzyme closure, thus hindering insertion. The structures reveal that an active site residue, Asp276, positions β-C-Fapy•dGTP so that it distorts the geometry of critical catalytic atoms. Removal of this guardian side chain permits enzyme closure and increases the efficiency of β-C-Fapy•dG insertion opposite dC. These results highlight the stringent requirements necessary to achieve a closed DNA polymerase active site poised for efficient nucleotide incorporation and illustrate how DNA polymerase β has evolved to hinder Fapy•dGTP insertion.
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Affiliation(s)
- Mallory R Smith
- Department of Biochemistry and Molecular Biology, and Department of Cancer Biology, University of Kansas Medical Center, 3901 Rainbow Blvd Mail Stop #3030, Kansas City, KS 66160, USA
| | - David D Shock
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, P.O. Box 12233, Research Triangle Park, NC 27709-2233, USA
| | - William A Beard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, P.O. Box 12233, Research Triangle Park, NC 27709-2233, USA
| | - Marc M Greenberg
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, and Department of Cancer Biology, University of Kansas Medical Center, 3901 Rainbow Blvd Mail Stop #3030, Kansas City, KS 66160, USA,Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, P.O. Box 12233, Research Triangle Park, NC 27709-2233, USA,To whom correspondence should be addressed. Tel: +1 913 588 5560;
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, P.O. Box 12233, Research Triangle Park, NC 27709-2233, USA,Correspondence may also be addressed to Samuel H. Wilson. Tel: +1 984 287 3451;
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18
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Foley MC, Couto L, Rauf S, Boyke A. Insights into DNA polymerase δ’s mechanism for accurate DNA replication. J Mol Model 2019; 25:80. [DOI: 10.1007/s00894-019-3957-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 02/05/2019] [Indexed: 11/28/2022]
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19
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Beard WA, Wilson SH. DNA polymerase beta and other gap-filling enzymes in mammalian base excision repair. Enzymes 2019; 45:1-26. [PMID: 31627875 DOI: 10.1016/bs.enz.2019.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
DNA polymerase β plays a central role in the base excision DNA repair pathway that cleanses the genome of apurinic/apyrimidinic (AP) sites. AP sites arise in DNA from spontaneous base loss and DNA damage-specific glycosylases that hydrolyze the N-glycosidic bond between the deoxyribose and damaged base. AP sites are deleterious lesions because they can be mutagenic and/or cytotoxic. DNA polymerase β contributes two enzymatic activities, DNA synthesis and lyase, during the repair of AP sites; these activities reside on carboxyl- and amino-terminal domains, respectively. Accordingly, its cellular, structural, and kinetic attributes have been extensively characterized and it serves as model enzyme for the nucleotidyl transferase reaction utilized by other replicative, repair, and trans-lesion DNA polymerases.
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Affiliation(s)
- William A Beard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Durham, NC, United States
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Durham, NC, United States.
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20
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Raper AT, Reed AJ, Suo Z. Kinetic Mechanism of DNA Polymerases: Contributions of Conformational Dynamics and a Third Divalent Metal Ion. Chem Rev 2018; 118:6000-6025. [DOI: 10.1021/acs.chemrev.7b00685] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Austin T. Raper
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Andrew J. Reed
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Zucai Suo
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
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21
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Loc'h J, Delarue M. Terminal deoxynucleotidyltransferase: the story of an untemplated DNA polymerase capable of DNA bridging and templated synthesis across strands. Curr Opin Struct Biol 2018; 53:22-31. [PMID: 29656238 DOI: 10.1016/j.sbi.2018.03.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/27/2018] [Accepted: 03/30/2018] [Indexed: 01/08/2023]
Abstract
Terminal deoxynucleotidyltransferase (TdT) is a member of the polX family which is involved in DNA repair. It has been known for years as an untemplated DNA polymerase used during V(D)J recombination to generate diversity at the CDR3 region of immunoglobulins and T-cell receptors. Recently, however, TdT was crystallized in the presence of a complete DNA synapsis made of two double-stranded DNA (dsDNA), each with a 3' protruding end, and overlapping with only one micro-homology base-pair, thus giving structural insight for the first time into DNA synthesis across strands. It was subsequently shown that TdT indeed has an in trans template-dependent activity in the presence of an excess of the downstream DNA duplex. A possible biological role of this dual activity is discussed.
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Affiliation(s)
- Jérôme Loc'h
- Unit of Structural Dynamics of Biological Macromolecules and UMR 3528 du CNRS, Institut Pasteur, 75015 Paris, France
| | - Marc Delarue
- Unit of Structural Dynamics of Biological Macromolecules and UMR 3528 du CNRS, Institut Pasteur, 75015 Paris, France.
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22
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Baranovskiy AG, Duong VN, Babayeva ND, Zhang Y, Pavlov YI, Anderson KS, Tahirov TH. Activity and fidelity of human DNA polymerase α depend on primer structure. J Biol Chem 2018; 293:6824-6843. [PMID: 29555682 DOI: 10.1074/jbc.ra117.001074] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/09/2018] [Indexed: 12/13/2022] Open
Abstract
DNA polymerase α (Polα) plays an important role in genome replication. In a complex with primase, Polα synthesizes chimeric RNA-DNA primers necessary for replication of both chromosomal DNA strands. During RNA primer extension with deoxyribonucleotides, Polα needs to use double-stranded helical substrates having different structures. Here, we provide a detailed structure-function analysis of human Polα's interaction with dNTPs and DNA templates primed with RNA, chimeric RNA-DNA, or DNA. We report the crystal structures of two ternary complexes of the Polα catalytic domain containing dCTP, a DNA template, and either a DNA or an RNA primer. Unexpectedly, in the ternary complex with a DNA:DNA duplex and dCTP, the "fingers" subdomain of Polα is in the open conformation. Polα induces conformational changes in the DNA and hybrid duplexes to produce the universal double helix form. Pre-steady-state kinetic studies indicated for both duplex types that chemical catalysis rather than product release is the rate-limiting step. Moreover, human Polα extended DNA primers with higher efficiency but lower processivity than it did with RNA and chimeric primers. Polα has a substantial propensity to make errors during DNA synthesis, and we observed that its fidelity depends on the type of sugar at the primer 3'-end. A detailed structural comparison of Polα with other replicative DNA polymerases disclosed common features and some differences, which may reflect the specialization of each polymerase in genome replication.
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Affiliation(s)
- Andrey G Baranovskiy
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
| | - Vincent N Duong
- the Departments of Pharmacology and Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06510
| | - Nigar D Babayeva
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
| | - Yinbo Zhang
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
| | - Youri I Pavlov
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and.,the Departments of Biochemistry and Molecular Biology, Pathology and Microbiology, and Genetics and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska 68198 and
| | - Karen S Anderson
- the Departments of Pharmacology and Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06510
| | - Tahir H Tahirov
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
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23
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Pannunzio NR, Watanabe G, Lieber MR. Nonhomologous DNA end-joining for repair of DNA double-strand breaks. J Biol Chem 2017; 293:10512-10523. [PMID: 29247009 DOI: 10.1074/jbc.tm117.000374] [Citation(s) in RCA: 333] [Impact Index Per Article: 47.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Nonhomologous DNA end-joining (NHEJ) is the predominant double-strand break (DSB) repair pathway throughout the cell cycle and accounts for nearly all DSB repair outside of the S and G2 phases. NHEJ relies on Ku to thread onto DNA termini and thereby improve the affinity of the NHEJ enzymatic components consisting of polymerases (Pol μ and Pol λ), a nuclease (the Artemis·DNA-PKcs complex), and a ligase (XLF·XRCC4·Lig4 complex). Each of the enzymatic components is distinctive for its versatility in acting on diverse incompatible DNA end configurations coupled with a flexibility in loading order, resulting in many possible junctional outcomes from one DSB. DNA ends can either be directly ligated or, if the ends are incompatible, processed until a ligatable configuration is achieved that is often stabilized by up to 4 bp of terminal microhomology. Processing of DNA ends results in nucleotide loss or addition, explaining why DSBs repaired by NHEJ are rarely restored to their original DNA sequence. Thus, NHEJ is a single pathway with multiple enzymes at its disposal to repair DSBs, resulting in a diversity of repair outcomes.
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Affiliation(s)
- Nicholas R Pannunzio
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
| | - Go Watanabe
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
| | - Michael R Lieber
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
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24
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Sastre-Moreno G, Pryor JM, Díaz-Talavera A, Ruiz JF, Ramsden DA, Blanco L. Polμ tumor variants decrease the efficiency and accuracy of NHEJ. Nucleic Acids Res 2017; 45:10018-10031. [PMID: 28973441 PMCID: PMC5622330 DOI: 10.1093/nar/gkx625] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/03/2017] [Accepted: 07/12/2017] [Indexed: 11/14/2022] Open
Abstract
The non homologous end-joining (NHEJ) pathway of double-strand break (DSB) repair often requires DNA synthesis to fill the gaps generated upon alignment of the broken ends, a complex task performed in human cells by two specialized DNA polymerases, Polλ and Polμ. It is now well established that Polμ is the one adapted to repair DSBs with non-complementary ends, the most challenging scenario, although the structural basis and physiological implications of this adaptation are not fully understood. Here, we demonstrate that two human Polμ point mutations, G174S and R175H, previously identified in two different tumor samples and affecting two adjacent residues, limit the efficiency of accurate NHEJ by Polμ in vitro and in vivo. Moreover, we show that this limitation is the consequence of a decreased template dependency during NHEJ, which renders the error-rate of the mutants higher due to the ability of Polμ to randomly incorporate nucleotides at DSBs. These results highlight the relevance of the 8 kDa domain of Polμ for accurate and efficient NHEJ, but also its contribution to the error-prone behavior of Polμ at 2-nt gaps. This work provides the first demonstration that mutations affecting Polμ identified in tumors can alter the efficiency and fidelity of NHEJ.
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Affiliation(s)
- Guillermo Sastre-Moreno
- Centro de Biología Molecular ‘Severo Ochoa’, Universidad Autónoma de Madrid/CSIC, Madrid, Spain
| | - John M. Pryor
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Alberto Díaz-Talavera
- Centro de Biología Molecular ‘Severo Ochoa’, Universidad Autónoma de Madrid/CSIC, Madrid, Spain
| | - José F. Ruiz
- Departamento Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla/CSIC, Sevilla, Spain
| | - Dale A. Ramsden
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Luis Blanco
- Centro de Biología Molecular ‘Severo Ochoa’, Universidad Autónoma de Madrid/CSIC, Madrid, Spain
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25
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van Loon B, Hübscher U, Maga G. Living on the Edge: DNA Polymerase Lambda between Genome Stability and Mutagenesis. Chem Res Toxicol 2017; 30:1936-1941. [DOI: 10.1021/acs.chemrestox.7b00152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Barbara van Loon
- Department
of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Erling Skjalgssons gt 1, N-7491 Trondheim, Norway
- Department
of Pathology and Medical Genetics, St. Olavs Hospital, Trondheim University Hospital, 7491 Trondheim, Norway
| | - Ulrich Hübscher
- Department
of Molecular Mechanisms of Disease, University of Zürich, Winterthurerstrasse
190, CH-8057 Zürich, Switzerland
| | - Giovanni Maga
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
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26
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Wu WJ, Yang W, Tsai MD. How DNA polymerases catalyse replication and repair with contrasting fidelity. Nat Rev Chem 2017. [DOI: 10.1038/s41570-017-0068] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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27
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Vyas R, Reed AJ, Raper AT, Zahurancik WJ, Wallenmeyer PC, Suo Z. Structural basis for the D-stereoselectivity of human DNA polymerase β. Nucleic Acids Res 2017; 45:6228-6237. [PMID: 28402499 PMCID: PMC5449621 DOI: 10.1093/nar/gkx252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/24/2017] [Accepted: 04/03/2017] [Indexed: 12/20/2022] Open
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) with L-stereochemistry have long been an effective treatment for viral infections because of the strong D-stereoselectivity exhibited by human DNA polymerases relative to viral reverse transcriptases. The D-stereoselectivity of DNA polymerases has only recently been explored structurally and all three DNA polymerases studied to date have demonstrated unique stereochemical selection mechanisms. Here, we have solved structures of human DNA polymerase β (hPolβ), in complex with single-nucleotide gapped DNA and L-nucleotides and performed pre-steady-state kinetic analysis to determine the D-stereoselectivity mechanism of hPolβ. Beyond a similar 180° rotation of the L-nucleotide ribose ring seen in other studies, the pre-catalytic ternary crystal structures of hPolβ, DNA and L-dCTP or the triphosphate forms of antiviral drugs lamivudine ((-)3TC-TP) and emtricitabine ((-)FTC-TP) provide little structural evidence to suggest that hPolβ follows the previously characterized mechanisms of D-stereoselectivity. Instead, hPolβ discriminates against L-stereochemistry through accumulation of several active site rearrangements that lead to a decreased nucleotide binding affinity and incorporation rate. The two NRTIs escape some of the active site selection through the base and sugar modifications but are selected against through the inability of hPolβ to complete thumb domain closure.
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Affiliation(s)
- Rajan Vyas
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Andrew J. Reed
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Austin T. Raper
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Walter J. Zahurancik
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Petra C. Wallenmeyer
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Zucai Suo
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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28
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Wyatt HDM, Laister RC, Martin SR, Arrowsmith CH, West SC. The SMX DNA Repair Tri-nuclease. Mol Cell 2017; 65:848-860.e11. [PMID: 28257701 PMCID: PMC5344696 DOI: 10.1016/j.molcel.2017.01.031] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/17/2017] [Accepted: 01/25/2017] [Indexed: 01/13/2023]
Abstract
The efficient removal of replication and recombination intermediates is essential for the maintenance of genome stability. Resolution of these potentially toxic structures requires the MUS81-EME1 endonuclease, which is activated at prometaphase by formation of the SMX tri-nuclease containing three DNA repair structure-selective endonucleases: SLX1-SLX4, MUS81-EME1, and XPF-ERCC1. Here we show that SMX tri-nuclease is more active than the three individual nucleases, efficiently cleaving replication forks and recombination intermediates. Within SMX, SLX4 co-ordinates the SLX1 and MUS81-EME1 nucleases for Holliday junction resolution, in a reaction stimulated by XPF-ERCC1. SMX formation activates MUS81-EME1 for replication fork and flap structure cleavage by relaxing substrate specificity. Activation involves MUS81's conserved N-terminal HhH domain, which mediates incision site selection and SLX4 binding. Cell cycle-dependent formation and activation of this tri-nuclease complex provides a unique mechanism by which cells ensure chromosome segregation and preserve genome integrity.
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Affiliation(s)
- Haley D M Wyatt
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Rob C Laister
- Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Stephen R Martin
- Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Cheryl H Arrowsmith
- Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Stephen C West
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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29
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Raper AT, Reed AJ, Gadkari VV, Suo Z. Advances in Structural and Single-Molecule Methods for Investigating DNA Lesion Bypass and Repair Polymerases. Chem Res Toxicol 2016; 30:260-269. [PMID: 28092942 DOI: 10.1021/acs.chemrestox.6b00342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Innovative advances in X-ray crystallography and single-molecule biophysics have yielded unprecedented insight into the mechanisms of DNA lesion bypass and damage repair. Time-dependent X-ray crystallography has been successfully applied to view the bypass of 8-oxo-7,8-dihydro-2'-deoxyguanine (8-oxoG), a major oxidative DNA lesion, and the incorporation of the triphosphate form, 8-oxo-dGTP, catalyzed by human DNA polymerase β. Significant findings of these studies are highlighted here, and their contributions to the current mechanistic understanding of mutagenic translesion DNA synthesis (TLS) and base excision repair are discussed. In addition, single-molecule Förster resonance energy transfer (smFRET) techniques have recently been adapted to investigate nucleotide binding and incorporation opposite undamaged dG and 8-oxoG by Sulfolobus solfataricus DNA polymerase IV (Dpo4), a model Y-family DNA polymerase. The mechanistic response of Dpo4 to a DNA lesion and the complex smFRET technique are described here. In this perspective, we also describe how time-dependent X-ray crystallography and smFRET can be used to achieve the spatial and temporal resolutions necessary to answer some of the mechanistic questions that remain in the fields of TLS and DNA damage repair.
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Affiliation(s)
- Austin T Raper
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
| | - Andrew J Reed
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
| | - Varun V Gadkari
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
| | - Zucai Suo
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
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30
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Burak MJ, Guja KE, Hambardjieva E, Derkunt B, Garcia-Diaz M. A fidelity mechanism in DNA polymerase lambda promotes error-free bypass of 8-oxo-dG. EMBO J 2016; 35:2045-59. [PMID: 27481934 DOI: 10.15252/embj.201694332] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/08/2016] [Indexed: 11/09/2022] Open
Abstract
8-oxo-7,8-dihydroxy-2'-deoxyguanosine (8-oxo-dG) has high mutagenic potential as it is prone to mispair with deoxyadenine (dA). In order to maintain genomic integrity, post-replicative 8-oxo-dG:dA mispairs are removed through DNA polymerase lambda (Pol λ)-dependent MUTYH-initiated base excision repair (BER). Here, we describe seven novel crystal structures and kinetic data that fully characterize 8-oxo-dG bypass by Pol λ. We demonstrate that Pol λ has a flexible active site that can tolerate 8-oxo-dG in either the anti- or syn-conformation. Importantly, we show that discrimination against the pro-mutagenic syn-conformation occurs at the extension step and identify the residue responsible for this selectivity. This residue acts as a kinetic switch, shunting repair toward long-patch BER upon correct dCMP incorporation, thus enhancing repair efficiency. Moreover, this switch also provides a potential mechanism to increase repair fidelity of MUTYH-initiated BER.
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Affiliation(s)
- Matthew J Burak
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Kip E Guja
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Elena Hambardjieva
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Burak Derkunt
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Miguel Garcia-Diaz
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
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31
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Liu MS, Tsai HY, Liu XX, Ho MC, Wu WJ, Tsai MD. Structural Mechanism for the Fidelity Modulation of DNA Polymerase λ. J Am Chem Soc 2016; 138:2389-98. [PMID: 26836966 DOI: 10.1021/jacs.5b13368] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The mechanism of DNA polymerase (pol) fidelity is of fundamental importance in chemistry and biology. While high-fidelity pols have been well studied, much less is known about how some pols achieve medium or low fidelity with functional importance. Here we examine how human DNA polymerase λ (Pol λ) achieves medium fidelity by determining 12 crystal structures and performing pre-steady-state kinetic analyses. We showed that apo-Pol λ exists in the closed conformation, unprecedentedly with a preformed MgdNTP binding pocket, and binds MgdNTP readily in the active conformation in the absence of DNA. Since prebinding of MgdNTP could lead to very low fidelity as shown previously, it is attenuated in Pol λ by a hydrophobic core including Leu431, Ile492, and the Tyr505/Phe506 motif. We then predicted and demonstrated that L431A mutation enhances MgdNTP prebinding and lowers the fidelity. We also hypothesized that the MgdNTP-prebinding ability could stabilize a mismatched ternary complex and destabilize a matched ternary complex, and provided evidence with structures in both forms. Our results demonstrate that, while high-fidelity pols follow a common paradigm, Pol λ has developed specific conformations and mechanisms for its medium fidelity. Structural comparison with other pols also suggests that different pols likely utilize different conformational changes and microscopic mechanisms to achieve their catalytic functions with varying fidelities.
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Affiliation(s)
- Mu-Sen Liu
- Institute of Biochemical Sciences, National Taiwan University , Taipei 106, Taiwan
| | | | | | - Meng-Chiao Ho
- Institute of Biochemical Sciences, National Taiwan University , Taipei 106, Taiwan
| | | | - Ming-Daw Tsai
- Institute of Biochemical Sciences, National Taiwan University , Taipei 106, Taiwan
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32
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Essential role for polymerase specialization in cellular nonhomologous end joining. Proc Natl Acad Sci U S A 2015; 112:E4537-45. [PMID: 26240371 DOI: 10.1073/pnas.1505805112] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nonhomologous end joining (NHEJ) repairs chromosome breaks and must remain effective in the face of extensive diversity in broken end structures. We show here that this flexibility is often reliant on the ability to direct DNA synthesis across strand breaks, and that polymerase (Pol) μ and Pol λ are the only mammalian DNA polymerases that have this activity. By systematically varying substrate in cells, we show each polymerase is uniquely proficient in different contexts. The templating nucleotide is also selected differently, with Pol μ using the unpaired base adjacent to the downstream 5' phosphate even when there are available template sites further upstream of this position; this makes Pol μ more flexible but also less accurate than Pol λ. Loss of either polymerase alone consequently has clear and distinguishable effects on the fidelity of repair, but end remodeling by cellular nucleases and the remaining polymerase helps mitigate the effects on overall repair efficiency. Accordingly, when cells are deficient in both polymerases there is synergistic impact on NHEJ efficiency, both in terms of repair of defined substrates and cellular resistance to ionizing radiation. Pol μ and Pol λ thus provide distinct solutions to a problem for DNA synthesis that is unique to this pathway and play a key role in conferring on NHEJ the flexibility required for accurate and efficient repair.
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33
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Burak MJ, Guja KE, Garcia-Diaz M. Nucleotide binding interactions modulate dNTP selectivity and facilitate 8-oxo-dGTP incorporation by DNA polymerase lambda. Nucleic Acids Res 2015. [PMID: 26220180 PMCID: PMC4652769 DOI: 10.1093/nar/gkv760] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
8-Oxo-7,8,-dihydro-2'-deoxyguanosine triphosphate (8-oxo-dGTP) is a major product of oxidative damage in the nucleotide pool. It is capable of mispairing with adenosine (dA), resulting in futile, mutagenic cycles of base excision repair. Therefore, it is critical that DNA polymerases discriminate against 8-oxo-dGTP at the insertion step. Because of its roles in oxidative DNA damage repair and non-homologous end joining, DNA polymerase lambda (Pol λ) may frequently encounter 8-oxo-dGTP. Here, we have studied the mechanisms of 8-oxo-dGMP incorporation and discrimination by Pol λ. We have solved high resolution crystal structures showing how Pol λ accommodates 8-oxo-dGTP in its active site. The structures indicate that when mispaired with dA, the oxidized nucleotide assumes the mutagenic syn-conformation, and is stabilized by multiple interactions. Steady-state kinetics reveal that two residues lining the dNTP binding pocket, Ala(510) and Asn(513), play differential roles in dNTP selectivity. Specifically, Ala(510) and Asn(513) facilitate incorporation of 8-oxo-dGMP opposite dA and dC, respectively. These residues also modulate the balance between purine and pyrimidine incorporation. Our results shed light on the mechanisms controlling 8-oxo-dGMP incorporation in Pol λ and on the importance of interactions with the incoming dNTP to determine selectivity in family X DNA polymerases.
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Affiliation(s)
| | | | - Miguel Garcia-Diaz
- To whom correspondence should be addressed. Tel: +1 631 444 3054; Fax: +1 631 4449749;
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34
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DNA polymerases β and λ and their roles in cell. DNA Repair (Amst) 2015; 29:112-26. [DOI: 10.1016/j.dnarep.2015.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 01/29/2015] [Accepted: 02/02/2015] [Indexed: 10/24/2022]
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35
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How a homolog of high-fidelity replicases conducts mutagenic DNA synthesis. Nat Struct Mol Biol 2015; 22:298-303. [PMID: 25775266 PMCID: PMC4469489 DOI: 10.1038/nsmb.2985] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 02/10/2015] [Indexed: 12/26/2022]
Abstract
All DNA replicases achieve high fidelity by a conserved mechanism, but each translesion polymerase carries out mutagenic DNA synthesis in its own way. Here we report crystal structures of human DNA polymerase ν (Pol ν), which is homologous to high-fidelity replicases and yet error-prone. Instead of a simple open-to-closed movement of the O helix upon binding of a correct incoming nucleotide, Pol ν has a different open state and requires the finger domain to swing sideways and undergo both opening and closing motions to accommodate the nascent base pair. A single amino acid substitution in the O-helix of the finger domain improves the fidelity of Pol ν nearly ten-fold. A unique cavity and the flexibility of the thumb domain allow Pol ν to generate and accommodate a looped-out primer strand. Primer loopout may be a mechanism for DNA trinucloetide-repeat expansion.
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36
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Abstract
In all living cells, DNA is the storage medium for genetic information. Being quite stable, DNA is well-suited for its role in storage and propagation of information, but RNA is also covalently included in DNA through various mechanisms. Recent studies also demonstrate useful aspects of including ribonucleotides in the genome during repair. Therefore, our understanding of the consequences of RNA inclusion into bacterial genomic DNA is just beginning, but with its high frequency of occurrence the consequences and potential benefits are likely to be numerous and diverse. In this review, we discuss the processes that cause ribonucleotide inclusion in genomic DNA, the pathways important for ribonucleotide removal and the consequences that arise should ribonucleotides remain nested in genomic DNA.
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Affiliation(s)
- Jeremy W. Schroeder
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Justin R. Randall
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lindsay A. Matthews
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lyle A. Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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37
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Beard WA, Shock DD, Batra VK, Prasad R, Wilson SH. Substrate-induced DNA polymerase β activation. J Biol Chem 2014; 289:31411-22. [PMID: 25261471 DOI: 10.1074/jbc.m114.607432] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DNA polymerases and substrates undergo conformational changes upon forming protein-ligand complexes. These conformational adjustments can hasten or deter DNA synthesis and influence substrate discrimination. From structural comparison of binary DNA and ternary DNA-dNTP complexes of DNA polymerase β, several side chains have been implicated in facilitating formation of an active ternary complex poised for chemistry. Site-directed mutagenesis of these highly conserved residues (Asp-192, Arg-258, Phe-272, Glu-295, and Tyr-296) and kinetic characterization provides insight into the role these residues play during correct and incorrect insertion as well as their role in conformational activation. The catalytic efficiencies for correct nucleotide insertion for alanine mutants were wild type ∼ R258A > F272A ∼ Y296A > E295A > D192A. Because the efficiencies for incorrect insertion were affected to about the same extent for each mutant, the effects on fidelity were modest (<5-fold). The R258A mutant exhibited an increase in the single-turnover rate of correct nucleotide insertion. This suggests that the wild-type Arg-258 side chain generates a population of non-productive ternary complexes. Structures of binary and ternary substrate complexes of the R258A mutant and a mutant associated with gastric carcinomas, E295K, provide molecular insight into intermediate structural conformations not appreciated previously. Although the R258A mutant crystal structures were similar to wild-type enzyme, the open ternary complex structure of E295K indicates that Arg-258 stabilizes a non-productive conformation of the primer terminus that would decrease catalysis. Significantly, the open E295K ternary complex binds two metal ions indicating that metal binding cannot overcome the modified interactions that have interrupted the closure of the N-subdomain.
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Affiliation(s)
- William A Beard
- From the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - David D Shock
- From the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Vinod K Batra
- From the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Rajendra Prasad
- From the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Samuel H Wilson
- From the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
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38
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Lacbay CM, Mancuso J, Lin YS, Bennett N, Götte M, Tsantrizos YS. Modular Assembly of Purine-like Bisphosphonates as Inhibitors of HIV-1 Reverse Transcriptase. J Med Chem 2014; 57:7435-49. [DOI: 10.1021/jm501010f] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Cyrus M. Lacbay
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
| | - John Mancuso
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
| | - Yih-Shyan Lin
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
| | - Nicholas Bennett
- Department
of Microbiology and Immunology, McGill University, 3775 University Street, Montreal, Quebec H3A 2B4, Canada
| | - Matthias Götte
- Department
of Microbiology and Immunology, McGill University, 3775 University Street, Montreal, Quebec H3A 2B4, Canada
- Department
of Biochemistry, McGill University, 3655 Sir William Osler Promenade, Montreal, Quebec H3G1Y6, Canada
- Department
of Medicine, Division of Experimental Medicine, McGill University, 1110
Pine Avenue West, Montreal, Quebec H3A 1A3, Canada
| | - Youla S. Tsantrizos
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
- Department
of Biochemistry, McGill University, 3655 Sir William Osler Promenade, Montreal, Quebec H3G1Y6, Canada
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39
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Taggart DJ, Dayeh DM, Fredrickson SW, Suo Z. N-terminal domains of human DNA polymerase lambda promote primer realignment during translesion DNA synthesis. DNA Repair (Amst) 2014; 22:41-52. [PMID: 25108835 DOI: 10.1016/j.dnarep.2014.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 07/12/2014] [Accepted: 07/14/2014] [Indexed: 12/23/2022]
Abstract
The X-family DNA polymerases λ (Polλ) and β (Polβ) possess similar 5'-2-deoxyribose-5-phosphate lyase (dRPase) and polymerase domains. Besides these domains, Polλ also possesses a BRCA1 C-terminal (BRCT) domain and a proline-rich domain at its N terminus. However, it is unclear how these non-enzymatic domains contribute to the unique biological functions of Polλ. Here, we used primer extension assays and a newly developed high-throughput short oligonucleotide sequencing assay (HT-SOSA) to compare the efficiency of lesion bypass and fidelity of human Polβ, Polλ and two N-terminal deletion constructs of Polλ during the bypass of either an abasic site or an 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) lesion. We demonstrate that the BRCT domain of Polλ enhances the efficiency of abasic site bypass by approximately 1.6-fold. In contrast, deletion of the N-terminal domains of Polλ did not affect the efficiency of 8-oxodG bypass relative to nucleotide incorporations opposite undamaged dG. HT-SOSA analysis demonstrated that Polλ and Polβ preferentially generated -1 or -2 frameshift mutations when bypassing an abasic site and the single or double base deletion frequency was highly sequence dependent. Interestingly, the BRCT and proline-rich domains of Polλ cooperatively promoted the generation of -2 frameshift mutations when the abasic site was situated within a sequence context that was susceptible to homology-driven primer realignment. Furthermore, both N-terminal domains of Polλ increased the generation of -1 frameshift mutations during 8-oxodG bypass and influenced the frequency of substitution mutations produced by Polλ opposite the 8-oxodG lesion. Overall, our data support a model wherein the BRCT and proline-rich domains of Polλ act cooperatively to promote primer/template realignment between DNA strands of limited sequence homology. This function of the N-terminal domains may facilitate the role of Polλ as a gap-filling polymerase within the non-homologous end joining pathway.
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Affiliation(s)
- David J Taggart
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Daniel M Dayeh
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA; The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
| | - Saul W Fredrickson
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA; Department of Microbiology, The Ohio State University, Columbus, OH, USA
| | - Zucai Suo
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA; The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA.
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40
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Structural basis for the binding and incorporation of nucleotide analogs with L-stereochemistry by human DNA polymerase λ. Proc Natl Acad Sci U S A 2014; 111:E3033-42. [PMID: 25015085 DOI: 10.1073/pnas.1401286111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although lamivudine and emtricitabine, two L-deoxycytidine analogs, have been widely used as antiviral drugs for years, a structural basis for D-stereoselectivity against L-dNTPs, enantiomers of natural nucleotides (D-dNTPs), by any DNA polymerase or reverse transcriptase has not been established due to lack of a ternary structure of a polymerase, DNA, and an incoming L-dNTP. Here, we report 2.10-2.25 Å ternary crystal structures of human DNA polymerase λ, DNA, and L-deoxycytidine 5'-triphosphate (L-dCTP), or the triphosphates of lamivudine ((-)3TC-TP) and emtricitabine ((-)FTC-TP) with four ternary complexes per asymmetric unit. The structures of these 12 ternary complexes reveal that relative to D-deoxycytidine 5'-triphosphate (D-dCTP) in the canonical ternary structure of Polλ-DNA-D-dCTP, L-dCTP, (-)3TC-TP, and (-)FTC-TP all have their ribose rotated by 180°. Among the four ternary complexes with a specific L-nucleotide, two are similar and show that the L-nucleotide forms three Watson-Crick hydrogen bonds with the templating nucleotide dG and adopts a chair-like triphosphate conformation. In the remaining two similar ternary complexes, the L-nucleotide surprisingly interacts with the side chain of a conserved active site residue R517 through one or two hydrogen bonds, whereas the templating dG is anchored by a hydrogen bond with the side chain of a semiconserved residue Y505. Furthermore, the triphosphate of the L-nucleotide adopts an unprecedented N-shaped conformation. Our mutagenic and kinetic studies further demonstrate that the side chain of R517 is critical for the formation of the abovementioned four complexes along proposed catalytic pathways for L-nucleotide incorporation and provide the structural basis for the D-stereoselectivity of a DNA polymerase.
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41
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Martin MJ, Blanco L. Decision-making during NHEJ: a network of interactions in human Polμ implicated in substrate recognition and end-bridging. Nucleic Acids Res 2014; 42:7923-34. [PMID: 24878922 PMCID: PMC4081086 DOI: 10.1093/nar/gku475] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Human Polμ is a DNA polymerase belonging to the X family that has been implicated in the non-homologous end-joining (NHEJ) pathway during repair of double-strand breaks in DNA. Loop1 is a flexible piece of Polμ which has a critical role during terminal transferase and end-joining activities: it acts as a pseudo-template when the template strand is discontinuous or unavailable, whilst diffusing away if present to avoid steric clashes. Mutational analysis and inspection of the 3D structures available allowed us to identify a network of residues in charge of sensing the presence or absence of discontinuities in the template strand, which will in turn determine the final position adopted by Loop1. This network is formed by the previously uncharacterized thumb mini-loop (NSH motif) and the positively charged helix N, which contribute to the correct positioning of Loop1 and to juxtapose the discontinuous template strand during NHEJ of incompatible ends. Accordingly, single mutation of specific conserved residues in these motifs, whilst irrelevant in most of the cases for gap filling, largely affected terminal transferase and end-joining activities. Other point mutations in the ‘hinges’ of Loop1, such as residues Phe385 or Phe389, corroborated the flexibility requirements of this motif.
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Affiliation(s)
- Maria Jose Martin
- Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), 28049 Madrid, Spain
| | - Luis Blanco
- Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), 28049 Madrid, Spain
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42
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Tsai MD. How DNA polymerases catalyze DNA replication, repair, and mutation. Biochemistry 2014; 53:2749-51. [PMID: 24716436 DOI: 10.1021/bi500417m] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ming-Daw Tsai
- Institute of Biological Chemistry, Academia Sinica , Nankang, Taipei 115, Taiwan , and Institute of Biochemical Sciences, National Taiwan University , Taipei 106, Taiwan
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43
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Bebenek K, Pedersen LC, Kunkel TA. Structure-function studies of DNA polymerase λ. Biochemistry 2014; 53:2781-92. [PMID: 24716527 PMCID: PMC4018081 DOI: 10.1021/bi4017236] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
![]()
DNA polymerase λ
(pol λ) functions in DNA repair with
its main roles considered to be filling short gaps during repair of
double-strand breaks by nonhomologous end joining and during base
excision repair. As indicated by structural and biochemical studies
over the past 10 years, pol λ shares many common properties
with other family X siblings (pol β, pol μ, and terminal
deoxynucleotidyl transferase) but also has unique structural features
that determine its specific functions. In this review, we consider
how structural studies over the past decade furthered our understanding
of the behavior and biological roles of pol λ.
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Affiliation(s)
- Katarzyna Bebenek
- Laboratory of Structural Biology and ‡Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health , Research Triangle Park, North Carolina 27709, United States
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44
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Mizushina Y, Kuriyama I, Yoshida H. Inhibition of DNA polymerase λ and associated inflammatory activities of extracts from steamed germinated soybeans. Food Funct 2014; 5:696-704. [PMID: 24519361 DOI: 10.1039/c3fo60650c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During the screening of selective DNA polymerase (pol) inhibitors from more than 50 plant food materials, we found that the extract from steamed germinated soybeans (Glycine max L.) inhibited human pol λ activity. Among the three processed soybean samples tested (boiled soybeans, steamed soybeans, and steamed germinated soybeans), both the hot water extract and organic solvent extract from the steamed germinated soybeans had the strongest pol λ inhibition. We previously isolated two glucosyl compounds, a cerebroside (glucosyl ceramide, AS-1-4, compound ) and a steroidal glycoside (eleutheroside A, compound ), from dried soybean, and these compounds were prevalent in the extracts of the steamed germinated soybeans as pol inhibitors. The hot water and organic solvent extracts of the steamed germinated soybeans and compounds and selectively inhibited the activity of eukaryotic pol λ in vitro but did not influence the activities of other eukaryotic pols, including those from the A-family (pol γ), B-family (pols α, δ, and ε), and Y-family (pols η, ι, and κ), and also showed no effect on the activity of pol β, which is of the same family (X) as pol λ. The tendency for in vitro pol λ inhibition by these extracts and compounds showed a positive correlation with the in vivo suppression of TPA (12-O-tetradecanoylphorbol-13-acetate)-induced inflammation in mouse ear. These results suggest that steamed germinated soybeans, especially the glucosyl compound components, may be useful for their anti-inflammatory properties.
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Affiliation(s)
- Yoshiyuki Mizushina
- Laboratory of Food & Nutritional Sciences, Faculty of Nutrition, Kobe Gakuin University, Nishi-ku, Kobe, Hyogo 651-2180, Japan.
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45
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Structures of the Leishmania infantum polymerase beta. DNA Repair (Amst) 2014; 18:1-9. [PMID: 24666693 DOI: 10.1016/j.dnarep.2014.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/28/2014] [Accepted: 03/01/2014] [Indexed: 11/21/2022]
Abstract
Protozoans of the genus Leishmania, the pathogenic agent causing leishmaniasis, encode the family X DNA polymerase Li Pol β. Here, we report the first crystal structures of Li Pol β. Our pre- and post-catalytic structures show that the polymerase adopts the common family X DNA polymerase fold. However, in contrast to other family X DNA polymerases, the dNTP-induced conformational changes in Li Pol β are much more subtle. Moreover, pre- and post-catalytic structures reveal that Li Pol β interacts with the template strand through a nonconserved, variable region known as loop3. Li Pol β Δloop3 mutants display a higher catalytic rate, catalytic efficiency and overall error rates with respect to WT Li Pol β. These results further demonstrate the subtle structural variability that exists within this family of enzymes and provides insight into how this variability underlies the substantial functional differences among their members.
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Wu WJ, Su MI, Wu JL, Kumar S, Lim LH, Wang CWE, Nelissen FHT, Chen MCC, Doreleijers JF, Wijmenga SS, Tsai MD. How a low-fidelity DNA polymerase chooses non-Watson-Crick from Watson-Crick incorporation. J Am Chem Soc 2014; 136:4927-37. [PMID: 24617852 DOI: 10.1021/ja4102375] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A dogma for DNA polymerase catalysis is that the enzyme binds DNA first, followed by MgdNTP. This mechanism contributes to the selection of correct dNTP by Watson-Crick base pairing, but it cannot explain how low-fidelity DNA polymerases overcome Watson-Crick base pairing to catalyze non-Watson-Crick dNTP incorporation. DNA polymerase X from the deadly African swine fever virus (Pol X) is a half-sized repair polymerase that catalyzes efficient dG:dGTP incorporation in addition to correct repair. Here we report the use of solution structures of Pol X in the free, binary (Pol X:MgdGTP), and ternary (Pol X:DNA:MgdGTP with dG:dGTP non-Watson-Crick pairing) forms, along with functional analyses, to show that Pol X uses multiple unprecedented strategies to achieve the mutagenic dG:dGTP incorporation. Unlike high fidelity polymerases, Pol X can prebind purine MgdNTP tightly and undergo a specific conformational change in the absence of DNA. The prebound MgdGTP assumes an unusual syn conformation stabilized by partial ring stacking with His115. Upon binding of a gapped DNA, also with a unique mechanism involving primarily helix αE, the prebound syn-dGTP forms a Hoogsteen base pair with the template anti-dG. Interestingly, while Pol X prebinds MgdCTP weakly, the correct dG:dCTP ternary complex is readily formed in the presence of DNA. H115A mutation disrupted MgdGTP binding and dG:dGTP ternary complex formation but not dG:dCTP ternary complex formation. The results demonstrate the first solution structural view of DNA polymerase catalysis, a unique DNA binding mode, and a novel mechanism for non-Watson-Crick incorporation by a low-fidelity DNA polymerase.
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Affiliation(s)
- Wen-Jin Wu
- Institute of Biological Chemistry, and ‡Genomics Research Center, Academia Sinica , 128 Academia Road Sec. 2, Nankang, Taipei 115, Taiwan
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Waters CA, Strande NT, Wyatt DW, Pryor JM, Ramsden DA. Nonhomologous end joining: a good solution for bad ends. DNA Repair (Amst) 2014; 17:39-51. [PMID: 24630899 DOI: 10.1016/j.dnarep.2014.02.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 01/27/2014] [Accepted: 02/10/2014] [Indexed: 12/27/2022]
Abstract
Double strand breaks pose unique problems for DNA repair, especially when broken ends possess complex structures that interfere with standard DNA transactions. Nonhomologous end joining can use multiple strategies to solve these problems. It further uses sophisticated means to ensure the strategy chosen provides the ideal balance of flexibility and accuracy.
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Affiliation(s)
- Crystal A Waters
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Natasha T Strande
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - David W Wyatt
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - John M Pryor
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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48
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Moon AF, Pryor JM, Ramsden DA, Kunkel TA, Bebenek K, Pedersen LC. Sustained active site rigidity during synthesis by human DNA polymerase μ. Nat Struct Mol Biol 2014; 21:253-60. [PMID: 24487959 PMCID: PMC4164209 DOI: 10.1038/nsmb.2766] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 12/26/2013] [Indexed: 01/09/2023]
Abstract
DNA polymerase μ (Pol μ) is the only template-dependent human DNA polymerase capable of repairing double-strand DNA breaks (DSBs) with unpaired 3' ends in nonhomologous end joining (NHEJ). To probe this function, we structurally characterized Pol μ's catalytic cycle for single-nucleotide incorporation. These structures indicate that, unlike other template-dependent DNA polymerases, Pol μ shows no large-scale conformational changes in protein subdomains, amino acid side chains or DNA upon dNTP binding or catalysis. Instead, the only major conformational change is seen earlier in the catalytic cycle, when the flexible loop 1 region repositions upon DNA binding. Pol μ variants with changes in loop 1 have altered catalytic properties and are partially defective in NHEJ. The results indicate that specific loop 1 residues contribute to Pol μ's unique ability to catalyze template-dependent NHEJ of DSBs with unpaired 3' ends.
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Affiliation(s)
- Andrea F Moon
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - John M Pryor
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Dale A Ramsden
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Thomas A Kunkel
- 1] Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA. [2] Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Katarzyna Bebenek
- 1] Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA. [2] Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Lars C Pedersen
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
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49
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Strittmatter T, Brockmann A, Pott M, Hantusch A, Brunner T, Marx A. Expanding the scope of human DNA polymerase λ and β inhibitors. ACS Chem Biol 2014; 9:282-90. [PMID: 24171552 DOI: 10.1021/cb4007562] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The exact biological functions of individual DNA polymerases still await clarification, and therefore appropriate reagents to probe their respective functions are required. In the present study, we report the development of a highly potent series of human DNA polymerase λ and β (pol λ and β) inhibitors based on the rhodanine scaffold. Both enzymes are involved in DNA repair and are thus considered as future drug targets. We expanded the chemical diversity of the small-molecule inhibitors arising from a high content screening and designed and synthesized 30 novel analogues. By biochemical evaluation, we discovered 23 highly active compounds against pol λ. Importantly, 10 of these small-molecules selectively inhibited pol λ and not the homologous pol β. We discovered 14 small-molecules that target pol β and found out that they are more potent than known inhibitors. We also investigated whether the discovered compounds sensitize cancer cells toward DNA-damaging reagents. Thus, we cotreated human colorectal cancer cells (Caco-2) with the small-molecule inhibitors and hydrogen peroxide or the approved drug temozolomide. Interestingly, the tested compounds sensitized Caco-2 cells to both genotoxic agents in a DNA repair pathway-dependent manner.
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Affiliation(s)
- Tobias Strittmatter
- Departments of Chemistry
and Biology, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Anette Brockmann
- Departments of Chemistry
and Biology, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Moritz Pott
- Departments of Chemistry
and Biology, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Annika Hantusch
- Departments of Chemistry
and Biology, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Thomas Brunner
- Departments of Chemistry
and Biology, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Andreas Marx
- Departments of Chemistry
and Biology, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
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50
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Wu S, Beard WA, Pedersen LG, Wilson SH. Structural comparison of DNA polymerase architecture suggests a nucleotide gateway to the polymerase active site. Chem Rev 2013; 114:2759-74. [PMID: 24359247 DOI: 10.1021/cr3005179] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Sangwook Wu
- Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States
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