1
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Shen Y, Li Y, Yan R. Structural basis for the inhibition mechanism of the DNA polymerase holoenzyme from mpox virus. Structure 2024; 32:654-661.e3. [PMID: 38579705 DOI: 10.1016/j.str.2024.03.004] [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: 11/05/2023] [Revised: 01/31/2024] [Accepted: 03/11/2024] [Indexed: 04/07/2024]
Abstract
There are three key components at the core of the mpox virus (MPXV) DNA polymerase holoenzyme: DNA polymerase F8, processivity factors A22, and the Uracil-DNA glycosylase E4. The holoenzyme is recognized as a vital antiviral target because MPXV replicates in the cytoplasm of host cells. Nucleotide analogs such as cidofovir and cytarabine (Ara-C) have shown potential in curbing MPXV replication and they also display promise against other poxviruses. However, the mechanism behind their inhibitory effects remains unclear. Here, we present the cryo-EM structure of the DNA polymerase holoenzyme F8/A22/E4 bound with its competitive inhibitor Ara-C-derived cytarabine triphosphate (Ara-CTP) at an overall resolution of 3.0 Å and reveal its inhibition mechanism. Ara-CTP functions as a direct chain terminator in proximity to the deoxycytidine triphosphate (dCTP)-binding site. The extra hydrogen bond formed with Asn665 makes it more potent in binding than dCTP. Asn665 is conserved among eukaryotic B-family polymerases.
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Affiliation(s)
- Yaping Shen
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang Province, China
| | - Yaning Li
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Renhong Yan
- Department of Biochemistry, Key University Laboratory of Metabolism and Health of Guangdong, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China.
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2
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Guan H, Nuth M, Scott RW, Parker MH, Strobel ED, Reitz AB, Kulp JL, Ricciardi RP. Potency of a small molecule that targets the molluscum contagiosum virus processivity factor increases when conjugated to a tripeptide. Antiviral Res 2024; 226:105899. [PMID: 38705201 DOI: 10.1016/j.antiviral.2024.105899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/07/2024]
Abstract
We recently developed compound FC-7269 for targeting the Molluscum contagiosum virus processivity factor (mD4) and demonstrated its ability to inhibit viral processive DNA synthesis in vitro and cellular infection of an mD4-dependent virus (Antiviral Res 211, 2023,105520). However, despite a thorough medicinal chemistry campaign we were unable to generate a potent second analog as a requisite for drug development. We overcame this impasse, by conjugating a short hydrophobic trivaline peptide to FC-7269 to produce FC-TriVal-7269 which significantly increased antiviral potency and reduced cellular toxicity.
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Affiliation(s)
- Hancheng Guan
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, USA
| | - Manunya Nuth
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, USA
| | | | | | | | | | - John L Kulp
- Conifer Point Pharmaceuticals, Doylestown, PA, USA
| | - Robert P Ricciardi
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, USA; Abramson Cancer Center, School of Medicine, University of Pennsylvania, USA.
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3
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Diatlova EA, Mechetin GV, Yudkina AV, Zharkov VD, Torgasheva NA, Endutkin AV, Shulenina OV, Konevega AL, Gileva IP, Shchelkunov SN, Zharkov DO. Correlated Target Search by Vaccinia Virus Uracil-DNA Glycosylase, a DNA Repair Enzyme and a Processivity Factor of Viral Replication Machinery. Int J Mol Sci 2023; 24:ijms24119113. [PMID: 37298065 DOI: 10.3390/ijms24119113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/13/2023] [Accepted: 05/21/2023] [Indexed: 06/12/2023] Open
Abstract
The protein encoded by the vaccinia virus D4R gene has base excision repair uracil-DNA N-glycosylase (vvUNG) activity and also acts as a processivity factor in the viral replication complex. The use of a protein unlike PolN/PCNA sliding clamps is a unique feature of orthopoxviral replication, providing an attractive target for drug design. However, the intrinsic processivity of vvUNG has never been estimated, leaving open the question whether it is sufficient to impart processivity to the viral polymerase. Here, we use the correlated cleavage assay to characterize the translocation of vvUNG along DNA between two uracil residues. The salt dependence of the correlated cleavage, together with the similar affinity of vvUNG for damaged and undamaged DNA, support the one-dimensional diffusion mechanism of lesion search. Unlike short gaps, covalent adducts partly block vvUNG translocation. Kinetic experiments show that once a lesion is found it is excised with a probability ~0.76. Varying the distance between two uracils, we use a random walk model to estimate the mean number of steps per association with DNA at ~4200, which is consistent with vvUNG playing a role as a processivity factor. Finally, we show that inhibitors carrying a tetrahydro-2,4,6-trioxopyrimidinylidene moiety can suppress the processivity of vvUNG.
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Affiliation(s)
- Evgeniia A Diatlova
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Grigory V Mechetin
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Anna V Yudkina
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Vasily D Zharkov
- Biology Department, Tomsk State University, 634050 Tomsk, Russia
| | - Natalia A Torgasheva
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Anton V Endutkin
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Olga V Shulenina
- NRC "Kurchatov Institute"-B. P. Konstantinov Petersburg Nuclear Physics Institute, Leningrad Region, 188300 Gatchina, Russia
| | - Andrey L Konevega
- NRC "Kurchatov Institute"-B. P. Konstantinov Petersburg Nuclear Physics Institute, Leningrad Region, 188300 Gatchina, Russia
| | - Irina P Gileva
- State Research Center of Virology and Biotechnology Vector, Novosibirsk Region, 630559 Koltsovo, Russia
| | - Sergei N Shchelkunov
- State Research Center of Virology and Biotechnology Vector, Novosibirsk Region, 630559 Koltsovo, Russia
| | - Dmitry O Zharkov
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russia
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4
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Li Y, Shen Y, Hu Z, Yan R. Structural basis for the assembly of the DNA polymerase holoenzyme from a monkeypox virus variant. SCIENCE ADVANCES 2023; 9:eadg2331. [PMID: 37075110 PMCID: PMC10115419 DOI: 10.1126/sciadv.adg2331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The ongoing global pandemic caused by a variant of the monkeypox (or mpox) virus (MPXV) has prompted widespread concern. The MPXV DNA polymerase holoenzyme, consisting of F8, A22, and E4, is vital for replicating the viral genome and represents a crucial target for the development of antiviral drugs. However, the assembly and working mechanism for the DNA polymerase holoenzyme of MPXV remains elusive. Here, we present the cryo-electron microscopy (cryo-EM) structure of the DNA polymerase holoenzyme at an overall resolution of 3.5 Å. Unexpectedly, the holoenzyme is assembled as a dimer of heterotrimers, of which the extra interface between the thumb domain of F8 and A22 shows a clash between A22 and substrate DNA, suggesting an autoinhibition state. Addition of exogenous double-stranded DNA shifts the hexamer into trimer exposing DNA binding sites, potentially representing a more active state. Our findings provide crucial steps toward developing targeted antiviral therapies for MPXV and related viruses.
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Affiliation(s)
- Yaning Li
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province 310024, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yaping Shen
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province 310024, China
| | - Ziwei Hu
- Department of Biochemistry, Key University Laboratory of Metabolism and Health of Guangdong, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province 518055, China
| | - Renhong Yan
- Department of Biochemistry, Key University Laboratory of Metabolism and Health of Guangdong, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province 518055, China
- Corresponding author.
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5
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Tang H, Zhang A. Human mpox: Biology, epidemiology, therapeutic options, and development of small molecule inhibitors. Med Res Rev 2023. [PMID: 36891882 DOI: 10.1002/med.21943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/22/2023] [Accepted: 02/26/2023] [Indexed: 03/10/2023]
Abstract
Although monkeypox (mpox) has been endemic in Western and Central Africa for 50 years, it has not received sufficient prophylactic and therapeutical attention to avoid evolving into an epidemic. From January 2022 to January 2023, more than 84,000 of mpox cases were reported from 110 countries worldwide. Case numbers appear to be rising every day, making mpox an increasing global public health threat for the foreseeable future. In this perspective, we review the known biology and epidemiology of mpox virus, together with the latest therapeutic options available for mpox treatment. Further, small molecule inhibitors against mpox virus and the future directions in this field are discussed as well.
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Affiliation(s)
- Hairong Tang
- Shanghai Frontiers Science Center for Drug Target Identification and Delivery, and the Engineering Research Center of Cell and Therapeutic Antibody of the Ministry of Education, School of Pharmaceutical Sciences, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Ao Zhang
- Shanghai Frontiers Science Center for Drug Target Identification and Delivery, and the Engineering Research Center of Cell and Therapeutic Antibody of the Ministry of Education, School of Pharmaceutical Sciences, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China.,Lingang Laboratory, Shanghai, China
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6
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Guan H, Nuth M, Isaacs SN, Xiao Y, Scott RW, Parker MH, Strobel ED, Kulp JL, Bailey TR, Reitz AB, Ricciardi RP. A small molecule that targets the processivity factor of molluscum contagiosum virus has therapeutic potential. Antiviral Res 2023; 211:105520. [PMID: 36603771 PMCID: PMC10209390 DOI: 10.1016/j.antiviral.2022.105520] [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: 06/16/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023]
Abstract
Molluscum contagiosum (MC) is an infectious disease that occurs only in humans with a tropism that is narrowly restricted to the outermost epidermal layer of the skin. Molluscum contagiosum virus (MCV) is the causative agent of MC which produces skin lesions that can persist for months to several years. MCV is efficiently transmitted by direct physical contact or by indirect contact with fomites. MC is most prevalent in children and immune compromised patients. The failure to develop a drug that targets MCV replication has been hampered for decades by the inability to propagate MCV in cell culture. To address this dilemma, we recently engineered a surrogate poxvirus expressing the MCV processivity factor (mD4) as the drug target. The mD4 protein is essential for viral replication by keeping the viral polymerase tethered to the DNA template. In this study we have designed and synthesized a lead compound (7269) that is able to prevent mD4 dependent processive DNA synthesis in vitro (IC50 = 6.8 μM) and effectively inhibit propagation of the mD4-VV surrogate virus in BSC-1 cells (EC50 = 13.2 μM) with negligible cytotoxicity. In human liver microsomes, 7269 was shown to be stable for almost 2 h. When tested for penetration into human cadaver skin in a formulated gel, the level of 7269 in the epidermal layer was nearly 100 times the concentration (EC50) needed to inhibit propagation of the mD4-VV surrogate virus in BSC-1 cells. The gel formulated 7269 was scored as a non-irritant on skin and shown to have a shelf-life that was completely stable after several months. In summary, 7269 is a potential Lead for becoming the first MCV anti-viral compound to treat MC and thereby, addresses this unmet medical need that has persisted for many decades.
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Affiliation(s)
- Hancheng Guan
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, USA
| | - Manunya Nuth
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, USA
| | - Stuart N Isaacs
- Perelman School of Medicine, University of Pennsylvania, USA
| | - Yuhong Xiao
- Perelman School of Medicine, University of Pennsylvania, USA
| | | | | | | | - John L Kulp
- Conifer Point Pharmaceuticals, Doylestown, PA, USA
| | | | | | - Robert P Ricciardi
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, USA; Abramson Cancer Center, School of Medicine, University of Pennsylvania, USA.
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7
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Peng Q, Xie Y, Kuai L, Wang H, Qi J, Gao GF, Shi Y. Structure of monkeypox virus DNA polymerase holoenzyme. Science 2023; 379:100-105. [PMID: 36520947 DOI: 10.1126/science.ade6360] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The World Health Organization declared mpox (or monkeypox) a public health emergency of international concern in July 2022, and prophylactic and therapeutic measures are in urgent need. The monkeypox virus (MPXV) has its own DNA polymerase F8, together with the processive cofactors A22 and E4, constituting the polymerase holoenzyme for genome replication. Here, we determined the holoenzyme structure in complex with DNA using cryo-electron microscopy at the global resolution of ~2.8 angstroms. The holoenzyme possesses an architecture that suggests a "forward sliding clamp" processivity mechanism for viral DNA replication. MPXV polymerase has a DNA binding mode similar to that of other B-family DNA polymerases from different species. These findings reveal the mechanism of the MPXV genome replication and may guide the development of anti-poxvirus drugs.
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Affiliation(s)
- Qi Peng
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yufeng Xie
- Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Lu Kuai
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Han Wang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,College of Future Technology, Peking University, Beijing 100871, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - George F Gao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China.,Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing 100101, China.,Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing 100052, China
| | - Yi Shi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing 100101, China.,Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing 100052, China
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8
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Guan H, Nuth M, Lee V, Lin C, Mitchell CH, Lu W, Scott RW, Parker MH, Kulp JL, Reitz AB, Ricciardi RP. Herpes Simplex Virus-1 infection in human primary corneal epithelial cells is blocked by a stapled peptide that targets processive DNA synthesis. Ocul Surf 2021; 19:313-321. [PMID: 33161128 PMCID: PMC8650797 DOI: 10.1016/j.jtos.2020.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/26/2020] [Accepted: 11/01/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE Acyclovir is most commonly used for treating ocular Herpes Keratitis, a leading cause of infectious blindness. However, emerging resistance to Acyclovir resulting from mutations in the thymidine kinase gene of Herpes Simplex Virus -1 (HSV-1), has prompted the need for new therapeutics directed against a different viral protein. One novel target is the HSV-1 Processivity Factor which is essential for tethering HSV-1 Polymerase to the viral genome to enable long-chain DNA synthesis. METHODS A series of peptides, based on the crystal structure of the C-terminus of HSV-1 Polymerase, were constructed with hydrocarbon staples to retain their alpha-helical conformation. The stapled peptides were tested for blocking both HSV-1 DNA synthesis and infection. The most effective peptide was further optimized by replacing its negative N-terminus with two hydrophobic valine residues. This di-valine stapled peptide was tested for inhibiting HSV-1 infection of human primary corneal epithelial cells. RESULTS The stapled peptides blocked HSV-1 DNA synthesis and HSV-1 infection. The unstapled control peptide had no inhibitory effects. Specificity of the stapled peptides was confirmed by their inabilities to block infection by an unrelated virus. Significantly, the optimized di-valine stapled peptide effectively blocked HSV-1 infection in human primary corneal epithelial cells with selectivity index of 11.6. CONCLUSIONS Hydrocarbon stapled peptides that simulate the α-helix from the C-terminus of HSV-1 DNA polymerase can specifically block DNA synthesis and infection of HSV-1 in human primary corneal epithelial cells. These stapled peptides provide a foundation for developing a topical therapeutic for treating human ocular Herpes Keratitis.
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Affiliation(s)
- Hancheng Guan
- Department of Basic and Translational Science, Penn Dental Medicine, USA
| | - Manunya Nuth
- Department of Basic and Translational Science, Penn Dental Medicine, USA
| | - Vivian Lee
- Scheie Eye Institute, University of Pennsylvania, USA
| | - Chenyan Lin
- Scheie Eye Institute, University of Pennsylvania, USA
| | - Claire H Mitchell
- Department of Basic and Translational Science, Penn Dental Medicine, USA
| | - Wennan Lu
- Department of Basic and Translational Science, Penn Dental Medicine, USA
| | | | | | | | | | - Robert P Ricciardi
- Department of Basic and Translational Science, Penn Dental Medicine, USA.
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9
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Pathak D, Kwon E, Kim DY. Selective interactions between mimivirus uracil-DNA glycosylase and inhibitory proteins determined by a single amino acid. J Struct Biol 2020; 211:107552. [PMID: 32569642 DOI: 10.1016/j.jsb.2020.107552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/06/2020] [Accepted: 06/16/2020] [Indexed: 11/27/2022]
Abstract
Uracil-N-glycosylase (UNG) is found in most organisms as well as in large DNA viruses. Its inhibitory proteins, including uracil glycosylase inhibitor (UGI) and p56, tightly bind to the active site of UNG by mimicking the DNA substrates. As the binding motifs are conserved in UNG family proteins, the inhibitory proteins bind to various UNG proteins across species. However, the intercalation residue that penetrates the DNA minor groove during uracil excision is not conserved among UNG proteins. To understand the role of the intercalation residue in their binding to the inhibitory proteins, we prepared mutants of mimivirus UNG, measured the binding affinity between the UNG mutants and inhibitory proteins, and analyzed the interactions based on the crystal structures of mimivirus UNG mutants complexed with UGI. The results show that mimivirus UNG, which harbors Tyr as an intercalation residue, did not interact with the inhibitory proteins intrinsically, whereas mutations of the intercalation residue to Phe or Leu resulted in tight interactions with UGI and p56; mutation to Met resulted in tight interactions only with p56. The crystal structures revealed that Phe and Leu stabilize the interactions by fitting into the hydrophobic pocket of UGI. These results show that differences in size and hydrophobicity of the intercalation residues determine the interactions between UNG family proteins and the inhibitory proteins, UGI and p56.
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Affiliation(s)
- Deepak Pathak
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, South Korea
| | - Eunju Kwon
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, South Korea.
| | - Dong Young Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, South Korea.
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10
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Mechetin GV, Endutkin AV, Diatlova EA, Zharkov DO. Inhibitors of DNA Glycosylases as Prospective Drugs. Int J Mol Sci 2020; 21:ijms21093118. [PMID: 32354123 PMCID: PMC7247160 DOI: 10.3390/ijms21093118] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/22/2022] Open
Abstract
DNA glycosylases are enzymes that initiate the base excision repair pathway, a major biochemical process that protects the genomes of all living organisms from intrinsically and environmentally inflicted damage. Recently, base excision repair inhibition proved to be a viable strategy for the therapy of tumors that have lost alternative repair pathways, such as BRCA-deficient cancers sensitive to poly(ADP-ribose)polymerase inhibition. However, drugs targeting DNA glycosylases are still in development and so far have not advanced to clinical trials. In this review, we cover the attempts to validate DNA glycosylases as suitable targets for inhibition in the pharmacological treatment of cancer, neurodegenerative diseases, chronic inflammation, bacterial and viral infections. We discuss the glycosylase inhibitors described so far and survey the advances in the assays for DNA glycosylase reactions that may be used to screen pharmacological libraries for new active compounds.
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Affiliation(s)
- Grigory V. Mechetin
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
| | - Anton V. Endutkin
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
| | - Evgeniia A. Diatlova
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
| | - Dmitry O. Zharkov
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
- Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russia
- Correspondence: ; Tel.: +7-383-363-5187
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11
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Nuth M, Guan H, Xiao Y, Kulp JL, Parker MH, Strobel ED, Isaacs SN, Scott RW, Reitz AB, Ricciardi RP. Mutation and structure guided discovery of an antiviral small molecule that mimics an essential C-Terminal tripeptide of the vaccinia D4 processivity factor. Antiviral Res 2018; 162:178-185. [PMID: 30578797 PMCID: PMC10124107 DOI: 10.1016/j.antiviral.2018.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/12/2018] [Accepted: 12/17/2018] [Indexed: 12/31/2022]
Abstract
The smallpox virus (variola) remains a bioterrorism threat since a majority of the human population has never been vaccinated. In the event of an outbreak, at least two drugs against different targets of variola are critical to circumvent potential viral mutants that acquire resistance. Vaccinia virus (VACV) is the model virus used in the laboratory for studying smallpox. The VACV processivity factor D4 is an ideal therapeutic target since it is both essential and specific for poxvirus replication. Recently, we identified a tripeptide (Gly-Phe-Ile) motif at the C-terminus of D4 that is conserved among poxviruses and is necessary for maintaining protein function. In the current work, a virtual screening for small molecule mimics of the tripeptide identified a thiophene lead that effectively inhibited VACV, cowpox virus, and rabbitpox virus in cell culture (EC50 = 8.4-19.7 μM) and blocked in vitro processive DNA synthesis (IC50 = 13.4 μM). Compound-binding to D4 was demonstrated through various biophysical methods and a dose-dependent retardation of the proteolysis of D4 proteins. This study highlights an inhibitor design strategy that exploits a susceptible region of the protein and identifies a novel scaffold for a broad-spectrum poxvirus inhibitor.
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Affiliation(s)
- Manunya Nuth
- Department of Microbiology, School of Dental Medicine and the Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hancheng Guan
- Department of Microbiology, School of Dental Medicine and the Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yuhong Xiao
- Department of Medicine, Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John L Kulp
- Conifer Point Pharmaceuticals, Doylestown, PA, USA
| | | | - Eric D Strobel
- Fox Chase Chemical Diversity Center, Inc., Doylestown, PA, USA
| | - Stuart N Isaacs
- Department of Medicine, Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Richard W Scott
- Fox Chase Chemical Diversity Center, Inc., Doylestown, PA, USA
| | - Allen B Reitz
- Fox Chase Chemical Diversity Center, Inc., Doylestown, PA, USA
| | - Robert P Ricciardi
- Department of Microbiology, School of Dental Medicine and the Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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12
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Czarnecki MW, Traktman P. The vaccinia virus DNA polymerase and its processivity factor. Virus Res 2017; 234:193-206. [PMID: 28159613 DOI: 10.1016/j.virusres.2017.01.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/29/2017] [Indexed: 10/20/2022]
Abstract
Vaccinia virus is the prototypic poxvirus. The 192 kilobase double-stranded DNA viral genome encodes most if not all of the viral replication machinery. The vaccinia virus DNA polymerase is encoded by the E9L gene. Sequence analysis indicates that E9 is a member of the B family of replicative polymerases. The enzyme has both polymerase and 3'-5' exonuclease activities, both of which are essential to support viral replication. Genetic analysis of E9 has identified residues and motifs whose alteration can confer temperature-sensitivity, drug resistance (phosphonoacetic acid, aphidicolin, cytosine arabinsode, cidofovir) or altered fidelity. The polymerase is involved both in DNA replication and in recombination. Although inherently distributive, E9 gains processivity by interacting in a 1:1 stoichiometry with a heterodimer of the A20 and D4 proteins. A20 binds to both E9 and D4 and serves as a bridge within the holoenzyme. The A20/D4 heterodimer has been purified and can confer processivity on purified E9. The interaction of A20 with D4 is mediated by the N'-terminus of A20. The D4 protein is an enzymatically active uracil DNA glycosylase. The DNA-scanning activity of D4 is proposed to keep the holoenzyme tethered to the DNA template but allow polymerase translocation. The crystal structure of D4, alone and in complex with A201-50 and/or DNA has been solved. Screens for low molecular weight compounds that interrupt the A201-50/D4 interface have yielded hits that disrupt processive DNA synthesis in vitro and/or inhibit plaque formation. The observation that an active DNA repair enzyme is an integral part of the holoenzyme suggests that DNA replication and repair may be coupled.
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Affiliation(s)
- Maciej W Czarnecki
- Departments of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, United States; Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Paula Traktman
- Departments of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, United States; Departments of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, United States; Departments of the Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, United States; Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, United States.
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13
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Nuth M, Guan H, Ricciardi RP. A Conserved Tripeptide Sequence at the C Terminus of the Poxvirus DNA Processivity Factor D4 Is Essential for Protein Integrity and Function. J Biol Chem 2016; 291:27087-27097. [PMID: 27836975 DOI: 10.1074/jbc.m116.761908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/11/2016] [Indexed: 12/27/2022] Open
Abstract
Vaccinia virus (VACV) is a poxvirus, and the VACV D4 protein serves both as a uracil-DNA glycosylase and as an essential component required for processive DNA synthesis. The VACV A20 protein has no known catalytic function itself but associates with D4 to form the D4-A20 heterodimer that functions as the poxvirus DNA processivity factor. The heterodimer enables the DNA polymerase to efficiently synthesize extended strands of DNA. Upon characterizing the interaction between D4 and A20, we observed that the C terminus of D4 is susceptible to perturbation. Further analysis demonstrated that a conserved hexapeptide stretch at the extreme C terminus of D4 is essential for maintaining protein integrity, as assessed by its requirement for the production of soluble recombinant protein that is functional in processive DNA synthesis. From the known crystal structures of D4, the C-terminal hexapeptide is shown to make intramolecular contact with residues spanning the inner core of the protein. Our mutational analysis revealed that a tripeptide motif (215GFI217) within the hexapeptide comprises apparent residues necessary for the contact. Prediction of protein disorder identified the hexapeptide and several regions upstream of Gly215 that comprise residues of the interface surfaces of the D4-A20 heterodimer. Our study suggests that 215GFI217 anchors these potentially dynamic upstream regions of the protein to maintain protein integrity. Unlike uracil-DNA glycosylases from diverse sources, where the C termini are disordered and do not form comparable intramolecular contacts, this feature may be unique to orthopoxviruses.
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Affiliation(s)
- Manunya Nuth
- From the Department of Microbiology, School of Dental Medicine and
| | - Hancheng Guan
- From the Department of Microbiology, School of Dental Medicine and
| | - Robert P Ricciardi
- From the Department of Microbiology, School of Dental Medicine and .,the Abramson Cancer Center, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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14
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Schormann N, Zhukovskaya N, Bedwell G, Nuth M, Gillilan R, Prevelige PE, Ricciardi RP, Banerjee S, Chattopadhyay D. Poxvirus uracil-DNA glycosylase-An unusual member of the family I uracil-DNA glycosylases. Protein Sci 2016; 25:2113-2131. [PMID: 27684934 DOI: 10.1002/pro.3058] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 11/07/2022]
Abstract
Uracil-DNA glycosylases are ubiquitous enzymes, which play a key role repairing damages in DNA and in maintaining genomic integrity by catalyzing the first step in the base excision repair pathway. Within the superfamily of uracil-DNA glycosylases family I enzymes or UNGs are specific for recognizing and removing uracil from DNA. These enzymes feature conserved structural folds, active site residues and use common motifs for DNA binding, uracil recognition and catalysis. Within this family the enzymes of poxviruses are unique and most remarkable in terms of amino acid sequences, characteristic motifs and more importantly for their novel non-enzymatic function in DNA replication. UNG of vaccinia virus, also known as D4, is the most extensively characterized UNG of the poxvirus family. D4 forms an unusual heterodimeric processivity factor by attaching to a poxvirus-specific protein A20, which also binds to the DNA polymerase E9 and recruits other proteins necessary for replication. D4 is thus integrated in the DNA polymerase complex, and its DNA-binding and DNA scanning abilities couple DNA processivity and DNA base excision repair at the replication fork. The adaptations necessary for taking on the new function are reflected in the amino acid sequence and the three-dimensional structure of D4. An overview of the current state of the knowledge on the structure-function relationship of D4 is provided here.
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Affiliation(s)
- Norbert Schormann
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Natalia Zhukovskaya
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Gregory Bedwell
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Manunya Nuth
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Richard Gillilan
- MacCHESS (Macromolecular Diffraction Facility at CHESS) Cornell University, Ithaca, New York, 14853
| | - Peter E Prevelige
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Robert P Ricciardi
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.,Abramson Cancer Center, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Surajit Banerjee
- Department of Chemistry and Chemical Biology, Cornell University, and NE-CAT, Argonne, Illinois, 60439
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15
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Burmeister WP, Tarbouriech N, Fender P, Contesto-Richefeu C, Peyrefitte CN, Iseni F. Crystal Structure of the Vaccinia Virus Uracil-DNA Glycosylase in Complex with DNA. J Biol Chem 2015; 290:17923-17934. [PMID: 26045555 DOI: 10.1074/jbc.m115.648352] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 11/06/2022] Open
Abstract
Vaccinia virus polymerase holoenzyme is composed of the DNA polymerase catalytic subunit E9 associated with its heterodimeric co-factor A20·D4 required for processive genome synthesis. Although A20 has no known enzymatic activity, D4 is an active uracil-DNA glycosylase (UNG). The presence of a repair enzyme as a component of the viral replication machinery suggests that, for poxviruses, DNA synthesis and base excision repair is coupled. We present the 2.7 Å crystal structure of the complex formed by D4 and the first 50 amino acids of A20 (D4·A201-50) bound to a 10-mer DNA duplex containing an abasic site resulting from the cleavage of a uracil base. Comparison of the viral complex with its human counterpart revealed major divergences in the contacts between protein and DNA and in the enzyme orientation on the DNA. However, the conformation of the dsDNA within both structures is very similar, suggesting a dominant role of the DNA conformation for UNG function. In contrast to human UNG, D4 appears rigid, and we do not observe a conformational change upon DNA binding. We also studied the interaction of D4·A201-50 with different DNA oligomers by surface plasmon resonance. D4 binds weakly to nonspecific DNA and to uracil-containing substrates but binds abasic sites with a Kd of <1.4 μm. This second DNA complex structure of a family I UNG gives new insight into the role of D4 as a co-factor of vaccinia virus DNA polymerase and allows a better understanding of the structural determinants required for UNG action.
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Affiliation(s)
- Wim P Burmeister
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France; CNRS, UVHCI, F-38000 Grenoble, France.
| | - Nicolas Tarbouriech
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France; CNRS, UVHCI, F-38000 Grenoble, France
| | - Pascal Fender
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France; CNRS, UVHCI, F-38000 Grenoble, France
| | - Céline Contesto-Richefeu
- Unité de Virologie, Institut de Recherche Biomédicale des Armées, F-91223 Brétigny-sur-Orge cedex, France
| | - Christophe N Peyrefitte
- Unité de Virologie, Institut de Recherche Biomédicale des Armées, F-91223 Brétigny-sur-Orge cedex, France; Emerging Pathogens Laboratory, Fondation Mérieux, F-69007 Lyon, France
| | - Frédéric Iseni
- Unité de Virologie, Institut de Recherche Biomédicale des Armées, F-91223 Brétigny-sur-Orge cedex, France.
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16
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Schormann N, Banerjee S, Ricciardi R, Chattopadhyay D. Binding of undamaged double stranded DNA to vaccinia virus uracil-DNA Glycosylase. BMC STRUCTURAL BIOLOGY 2015; 15:10. [PMID: 26031450 PMCID: PMC4450493 DOI: 10.1186/s12900-015-0037-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/21/2015] [Indexed: 01/10/2023]
Abstract
BACKGROUND Uracil-DNA glycosylases are evolutionarily conserved DNA repair enzymes. However, vaccinia virus uracil-DNA glycosylase (known as D4), also serves as an intrinsic and essential component of the processive DNA polymerase complex during DNA replication. In this complex D4 binds to a unique poxvirus specific protein A20 which tethers it to the DNA polymerase. At the replication fork the DNA scanning and repair function of D4 is coupled with DNA replication. So far, DNA-binding to D4 has not been structurally characterized. RESULTS This manuscript describes the first structure of a DNA-complex of a uracil-DNA glycosylase from the poxvirus family. This also represents the first structure of a uracil DNA glycosylase in complex with an undamaged DNA. In the asymmetric unit two D4 subunits bind simultaneously to complementary strands of the DNA double helix. Each D4 subunit interacts mainly with the central region of one strand. DNA binds to the opposite side of the A20-binding surface on D4. Comparison of the present structure with the structure of uracil-containing DNA-bound human uracil-DNA glycosylase suggests that for DNA binding and uracil removal D4 employs a unique set of residues and motifs that are highly conserved within the poxvirus family but different in other organisms. CONCLUSION The first structure of D4 bound to a truly non-specific undamaged double-stranded DNA suggests that initial binding of DNA may involve multiple non-specific interactions between the protein and the phosphate backbone.
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Affiliation(s)
- Norbert Schormann
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| | - Surajit Banerjee
- Northeastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne, Chicago, IL, 60439, USA.
| | - Robert Ricciardi
- Department of Microbiology, School of Dental Medicine, Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Debasish Chattopadhyay
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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17
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Schormann N, Ricciardi R, Chattopadhyay D. Uracil-DNA glycosylases-structural and functional perspectives on an essential family of DNA repair enzymes. Protein Sci 2014; 23:1667-85. [PMID: 25252105 DOI: 10.1002/pro.2554] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/16/2014] [Indexed: 12/26/2022]
Abstract
Uracil-DNA glycosylases (UDGs) are evolutionarily conserved DNA repair enzymes that initiate the base excision repair pathway and remove uracil from DNA. The UDG superfamily is classified into six families based on their substrate specificity. This review focuses on the family I enzymes since these are the most extensively studied members of the superfamily. The structural basis for substrate specificity and base recognition as well as for DNA binding, nucleotide flipping and catalytic mechanism is discussed in detail. Other topics include the mechanism of lesion search and molecular mimicry through interaction with uracil-DNA glycosylase inhibitors. The latest studies and findings detailing structure and function in the UDG superfamily are presented.
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Affiliation(s)
- N Schormann
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, 35294
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18
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A novel target and approach for identifying antivirals against molluscum contagiosum virus. Antimicrob Agents Chemother 2014; 58:7383-9. [PMID: 25267668 DOI: 10.1128/aac.03660-14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The dermatological disease molluscum contagiosum (MC) presents as lesions restricted solely to the skin. The poxvirus molluscum contagiosum virus (MCV) is responsible for this skin disease that is easily transmitted through casual contact among all populations, with greater frequency in children and immunosuppressed individuals. In addition, sexual transmission of MCV in adolescents and adults is a health concern. Although the skin lesions ultimately resolve in immunocompetent individuals, they can persist for extended periods, be painful, and result in scarring. Treatment is problematic, and there is no drug that specifically targets MCV. The inability of MCV to propagate in cell culture has impeded drug development. To overcome these barriers, we integrated three new developments. First, we identified a new MCV drug target (mD4) that is essential for processive DNA synthesis in vitro. Second, we discovered a small chemical compound that binds to mD4 and prevents DNA synthesis in vitro. Third, and most significant, we engineered a hybrid vaccinia virus (mD4-VV) in which the natural vaccinia D4 (vD4) gene is replaced by the mD4 target gene. This hybrid virus is dependent on mD4 for viral growth in culture and is inhibited by the small compound. This target system provides, for the first time, a platform and approach for the discovery and evaluation of new therapeutics that can be used to treat MC.
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19
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Contesto-Richefeu C, Tarbouriech N, Brazzolotto X, Betzi S, Morelli X, Burmeister WP, Iseni F. Crystal structure of the vaccinia virus DNA polymerase holoenzyme subunit D4 in complex with the A20 N-terminal domain. PLoS Pathog 2014; 10:e1003978. [PMID: 24603707 PMCID: PMC3946371 DOI: 10.1371/journal.ppat.1003978] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 01/21/2014] [Indexed: 12/21/2022] Open
Abstract
Vaccinia virus polymerase holoenzyme is composed of the DNA polymerase E9, the uracil-DNA glycosylase D4 and A20, a protein with no known enzymatic activity. The D4/A20 heterodimer is the DNA polymerase co-factor whose function is essential for processive DNA synthesis. Genetic and biochemical data have established that residues located in the N-terminus of A20 are critical for binding to D4. However, no information regarding the residues of D4 involved in A20 binding is yet available. We expressed and purified the complex formed by D4 and the first 50 amino acids of A20 (D4/A20₁₋₅₀). We showed that whereas D4 forms homodimers in solution when expressed alone, D4/A20₁₋₅₀ clearly behaves as a heterodimer. The crystal structure of D4/A20₁₋₅₀ solved at 1.85 Å resolution reveals that the D4/A20 interface (including residues 167 to 180 and 191 to 206 of D4) partially overlaps the previously described D4/D4 dimer interface. A20₁₋₅₀ binding to D4 is mediated by an α-helical domain with important leucine residues located at the very N-terminal end of A20 and a second stretch of residues containing Trp43 involved in stacking interactions with Arg167 and Pro173 of D4. Point mutations of the latter residues disturb D4/A20₁₋₅₀ formation and reduce significantly thermal stability of the complex. Interestingly, small molecule docking with anti-poxvirus inhibitors selected to interfere with D4/A20 binding could reproduce several key features of the D4/A20₁₋₅₀ interaction. Finally, we propose a model of D4/A20₁₋₅₀ in complex with DNA and discuss a number of mutants described in the literature, which affect DNA synthesis. Overall, our data give new insights into the assembly of the poxvirus DNA polymerase cofactor and may be useful for the design and rational improvement of antivirals targeting the D4/A20 interface.
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Affiliation(s)
| | - Nicolas Tarbouriech
- Université Grenoble Alpes, UVHCI, Grenoble, France
- CNRS, UVHCI, Grenoble, France
- Unit for Virus Host-Cell Interactions, UMI 3265, Université Grenoble Alpes-EMBL-CNRS, Grenoble, France
| | - Xavier Brazzolotto
- Département de Toxicologie et Risque Chimique, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
| | - Stéphane Betzi
- Centre de Recherche en Cancérologie de Marseille (CRCM), CNRS UMR 7258, INSERM U 1068, Institut Paoli-Calmettes & Aix-Marseille Universités, Marseille, France
| | - Xavier Morelli
- Centre de Recherche en Cancérologie de Marseille (CRCM), CNRS UMR 7258, INSERM U 1068, Institut Paoli-Calmettes & Aix-Marseille Universités, Marseille, France
| | - Wim P. Burmeister
- Université Grenoble Alpes, UVHCI, Grenoble, France
- CNRS, UVHCI, Grenoble, France
- Unit for Virus Host-Cell Interactions, UMI 3265, Université Grenoble Alpes-EMBL-CNRS, Grenoble, France
| | - Frédéric Iseni
- Unité de Virologie, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
- * E-mail:
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20
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Nuth M, Guan H, Zhukovskaya N, Saw YL, Ricciardi RP. Design of Potent Poxvirus Inhibitors of the Heterodimeric Processivity Factor Required for Viral Replication. J Med Chem 2013; 56:3235-46. [DOI: 10.1021/jm301735k] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Manunya Nuth
- Department of Microbiology,
School of Dental Medicine, University of Pennsylvania, Pennsylvania
19104, United States
| | - Hancheng Guan
- Department of Microbiology,
School of Dental Medicine, University of Pennsylvania, Pennsylvania
19104, United States
| | - Natalia Zhukovskaya
- Department of Microbiology,
School of Dental Medicine, University of Pennsylvania, Pennsylvania
19104, United States
| | - Yih Ling Saw
- Department of Microbiology,
School of Dental Medicine, University of Pennsylvania, Pennsylvania
19104, United States
| | - Robert P. Ricciardi
- Department of Microbiology,
School of Dental Medicine, University of Pennsylvania, Pennsylvania
19104, United States
- Abramson
Cancer Center, School
of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
19104, United States
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21
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Sartmatova D, Nash T, Schormann N, Nuth M, Ricciardi R, Banerjee S, Chattopadhyay D. Crystallization and preliminary X-ray diffraction analysis of three recombinant mutants of Vaccinia virus uracil DNA glycosylase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:295-301. [PMID: 23519808 PMCID: PMC3606578 DOI: 10.1107/s1744309113002716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 01/27/2013] [Indexed: 11/10/2022]
Abstract
Amino-acid residues located at a highly flexible area in the uracil DNA glycosylase of Vaccinia virus were mutated. In the crystal structure of wild-type D4 these residues lie at the dimer interface. Specifically, three mutants were generated: (i) residue Arg167 was replaced with an alanine (R167AD4), (ii) residues Glu171, Ser172 and Pro173 were substituted with three glycine residues (3GD4) and (iii) residues Glu171 and Ser172 were deleted (Δ171-172D4). Mutant proteins were expressed, purified and crystallized in order to investigate the effects of these mutations on the structure of the protein.
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Affiliation(s)
- Darika Sartmatova
- Science and Technology Honors Program, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Taishayla Nash
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Norbert Schormann
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Manunya Nuth
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert Ricciardi
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Surajit Banerjee
- North-Eastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne, IL 60439, USA
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22
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Schormann N, Sommers CI, Prichard MN, Keith KA, Noah JW, Nuth M, Ricciardi RP, Chattopadhyay D. Identification of protein-protein interaction inhibitors targeting vaccinia virus processivity factor for development of antiviral agents. Antimicrob Agents Chemother 2011; 55:5054-62. [PMID: 21844323 PMCID: PMC3195037 DOI: 10.1128/aac.00278-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 08/05/2011] [Indexed: 01/11/2023] Open
Abstract
Poxvirus uracil DNA glycosylase D4 in association with A20 and the catalytic subunit of DNA polymerase forms the processive polymerase complex. The binding of D4 and A20 is essential for processive polymerase activity. Using an AlphaScreen assay, we identified compounds that inhibit protein-protein interactions between D4 and A20. Effective interaction inhibitors exhibited both antiviral activity and binding to D4. These results suggest that novel antiviral agents that target the protein-protein interactions between D4 and A20 can be developed for the treatment of infections with poxviruses, including smallpox.
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Affiliation(s)
| | | | - Mark N. Prichard
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Kathy A. Keith
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - James W. Noah
- Southern Research Institute, Birmingham, Alabama 35147
| | - Manunya Nuth
- Department of Microbiology, School of Dental Medicine
| | - Robert P. Ricciardi
- Department of Microbiology, School of Dental Medicine
- Abramson Cancer Center, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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23
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Boyle KA, Stanitsa ES, Greseth MD, Lindgren JK, Traktman P. Evaluation of the role of the vaccinia virus uracil DNA glycosylase and A20 proteins as intrinsic components of the DNA polymerase holoenzyme. J Biol Chem 2011; 286:24702-13. [PMID: 21572084 PMCID: PMC3137046 DOI: 10.1074/jbc.m111.222216] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 05/09/2011] [Indexed: 01/04/2023] Open
Abstract
The vaccinia virus DNA polymerase is inherently distributive but acquires processivity by associating with a heterodimeric processivity factor comprised of the viral A20 and D4 proteins. D4 is also an enzymatically active uracil DNA glycosylase (UDG). The presence of an active repair protein as an essential component of the polymerase holoenzyme is a unique feature of the replication machinery. We have shown previously that the A20-UDG complex has a stoichiometry of ∼1:1, and our data suggest that A20 serves as a bridge between polymerase and UDG. Here we show that conserved hydrophobic residues in the N' terminus of A20 are important for its binding to UDG. Our data argue against the assembly of D4 into higher order multimers, suggesting that the processivity factor does not form a toroidal ring around the DNA. Instead, we hypothesize that the intrinsic, processive DNA scanning activity of UDG tethers the holoenzyme to the DNA template. The inclusion of UDG as an essential holoenzyme component suggests that replication and base excision repair may be coupled. Here we show that the DNA polymerase can utilize dUTP as a substrate in vitro. Moreover, uracil moieties incorporated into the nascent strand during holoenzyme-mediated DNA synthesis can be excised by the viral UDG present within this holoenzyme, leaving abasic sites. Finally, we show that the polymerase stalls upon encountering an abasic site in the template strand, indicating that, like many replicative polymerases, the poxviral holoenzyme cannot perform translesion synthesis across an abasic site.
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Affiliation(s)
- Kathleen A. Boyle
- From the Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Eleni S. Stanitsa
- From the Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Matthew D. Greseth
- From the Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Jill K. Lindgren
- From the Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Paula Traktman
- From the Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
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24
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Kazlauskas D, Venclovas C. Computational analysis of DNA replicases in double-stranded DNA viruses: relationship with the genome size. Nucleic Acids Res 2011; 39:8291-305. [PMID: 21742758 PMCID: PMC3201878 DOI: 10.1093/nar/gkr564] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Genome duplication in free-living cellular organisms is performed by DNA replicases that always include a DNA polymerase, a DNA sliding clamp and a clamp loader. What are the evolutionary solutions for DNA replicases associated with smaller genomes? Are there some general principles? To address these questions we analyzed DNA replicases of double-stranded (ds) DNA viruses. In the process we discovered highly divergent B-family DNA polymerases in phiKZ-like phages and remote sliding clamp homologs in Ascoviridae family and Ma-LMM01 phage. The analysis revealed a clear dependency between DNA replicase components and the viral genome size. As the genome size increases, viruses universally encode their own DNA polymerases and frequently have homologs of DNA sliding clamps, which sometimes are accompanied by clamp loader subunits. This pattern is highly non-random. The absence of sliding clamps in large viral genomes usually coincides with the presence of atypical polymerases. Meanwhile, sliding clamp homologs, not accompanied by clamp loaders, have an elevated positive electrostatic potential, characteristic of non-ring viral processivity factors that bind the DNA directly. Unexpectedly, we found that similar electrostatic properties are shared by the eukaryotic 9-1-1 clamp subunits, Hus1 and, to a lesser extent, Rad9, also suggesting the possibility of direct DNA binding.
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Affiliation(s)
- Darius Kazlauskas
- Institute of Biotechnology, Vilnius University, Graičiūno 8, LT-02241 Vilnius, Lithuania
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Nuth M, Huang L, Saw YL, Schormann N, Chattopadhyay D, Ricciardi RP. Identification of inhibitors that block vaccinia virus infection by targeting the DNA synthesis processivity factor D4. J Med Chem 2011; 54:3260-7. [PMID: 21438571 DOI: 10.1021/jm101554k] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Smallpox was globally eradicated 30 years ago by vaccination. The recent threat of bioterrorism demands the development of improved vaccines and novel therapeutics to effectively preclude a reemergence of smallpox. One new therapeutic target is the vaccinia poxvirus processivity complex, comprising D4 and A20 proteins that enable the viral E9 DNA polymerase to synthesize extended strands. Five compounds identified from an AlphaScreen assay designed to disrupt A20:D4 binding were shown to be effective in: (i) blocking vaccinia processive DNA synthesis in vitro, (ii) preventing cellular infection with minimal cytotoxicity, and (iii) binding to D4, as evidenced by ThermoFluor. The EC(50) values for inhibition of viral infectivity ranged from 9.6 to 23 μM with corresponding selectivity indices (cytotoxicity CC(50)/viral infectivity EC(50)) of 3.9 to 17.8. The five compounds are thus potential therapeutics capable of halting smallpox DNA synthesis and infectivity through disruptive action against a component of the vaccinia processivity complex.
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Affiliation(s)
- Manunya Nuth
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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