1
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Tang Y, Zhang J, Guan J, Liang W, Petassi M, Zhang Y, Jiang X, Wang M, Wu W, Ou HY, Peters J. Transposition with Tn3-family elements occurs through interaction with the host β-sliding clamp processivity factor. Nucleic Acids Res 2024; 52:10416-10430. [PMID: 39119921 PMCID: PMC11417375 DOI: 10.1093/nar/gkae674] [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: 03/01/2024] [Revised: 07/18/2024] [Accepted: 07/23/2024] [Indexed: 08/10/2024] Open
Abstract
Tn3 family transposons are a widespread group of replicative transposons, notorious for contributing to the dissemination of antibiotic resistance, particularly the global prevalence of carbapenem resistance. The transposase (TnpA) of these elements catalyzes DNA breakage and rejoining reactions required for transposition. However, the molecular mechanism for target site selection with these elements remains unclear. Here, we identify a QLxxLR motif in N-terminal of Tn3 TnpAs and demonstrate that this motif allows interaction between TnpA of Tn3 family transposon Tn1721 and the host β-sliding clamp (DnaN), the major processivity factor of the DNA replication machinery. The TnpA-DnaN interaction is essential for Tn1721 transposition. Our work unveils a mechanism whereby Tn3 family transposons can bias transposition into certain replisomes through an interaction with the host replication machinery. This study further expands the diversity of mobile elements that use interaction with the host replication machinery to bias integration.
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Affiliation(s)
- Yu Tang
- Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200123, China
| | - Jianfeng Zhang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai 200040, China
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiahao Guan
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wei Liang
- Department of Laboratory Medicine, The First Affiliated Hospital of Ningbo University, Ningbo 315010, China
| | - Michael T Petassi
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Yumeng Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaofei Jiang
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Minggui Wang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Wenjuan Wu
- Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200123, China
| | - Hong-Yu Ou
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
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2
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Mahdi S, Lim S, Bezsonova I, Beuning PJ, Korzhnev DM. The backbone NMR resonance assignments of the stabilized E. coli β clamp. BIOMOLECULAR NMR ASSIGNMENTS 2024:10.1007/s12104-024-10202-5. [PMID: 39269602 DOI: 10.1007/s12104-024-10202-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2024] [Accepted: 09/04/2024] [Indexed: 09/15/2024]
Abstract
The 81 kDa E. coli β clamp is a ring-shaped head-to-tail homodimer that encircles DNA and plays a central role in bacterial DNA replication by serving as a processivity factor for DNA polymerases and a binding platform for other DNA replication and repair proteins. Here we report the backbone 1H, 15N, and 13C NMR resonance assignments of the stabilized T45R/S107R β clamp variant obtained using standard TROSY-based triple-resonance experiments (BMRB 52548). The backbone assignments were aided by 13C and 15N edited NOESY experiments, allowing us to utilize our previously reported assignments of the β clamp ILV side-chain methyl groups (BMRB 51430, 51431). The backbone assignments of the T45R/S107R β clamp variant were transferred to the wild-type β clamp using a minimal set of TROSY-based 15N edited NOESY, NHCO and NHCA experiments (BMRB 52549). The reported backbone and previous ILV side-chain resonance assignments will enable NMR studies of the β clamp interactions and dynamics using amide and methyl groups as probes.
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Affiliation(s)
- Sam Mahdi
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Socheata Lim
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Irina Bezsonova
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Penny J Beuning
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, 02115, USA
| | - Dmitry M Korzhnev
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA.
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3
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Marrin ME, Foster MR, Santana CM, Choi Y, Jassal AS, Rancic SJ, Greenwald CR, Drucker MN, Feldman DT, Thrall ES. The translesion polymerase Pol Y1 is a constitutive component of the B. subtilis replication machinery. Nucleic Acids Res 2024; 52:9613-9629. [PMID: 39051562 PMCID: PMC11381352 DOI: 10.1093/nar/gkae637] [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: 10/06/2023] [Revised: 07/03/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
Unrepaired DNA damage encountered by the cellular replication machinery can stall DNA replication, ultimately leading to cell death. In the DNA damage tolerance pathway translesion synthesis (TLS), replication stalling is alleviated by the recruitment of specialized polymerases to synthesize short stretches of DNA near a lesion. Although TLS promotes cell survival, most TLS polymerases are low-fidelity and must be tightly regulated to avoid harmful mutagenesis. The gram-negative bacterium Escherichia coli has served as the model organism for studies of the molecular mechanisms of bacterial TLS. However, it is poorly understood whether these same mechanisms apply to other bacteria. Here, we use in vivo single-molecule fluorescence microscopy to investigate the TLS polymerase Pol Y1 in the model gram-positive bacterium Bacillus subtilis. We find significant differences in the localization and dynamics of Pol Y1 in comparison to its E. coli homolog, Pol IV. Notably, Pol Y1 is constitutively enriched at or near sites of replication in the absence of DNA damage through interactions with the DnaN clamp; in contrast, Pol IV has been shown to be selectively enriched only upon replication stalling. These results suggest key differences in the roles and mechanisms of regulation of TLS polymerases across different bacterial species.
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Affiliation(s)
- McKayla E Marrin
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Michael R Foster
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Chloe M Santana
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Yoonhee Choi
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Avtar S Jassal
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Sarah J Rancic
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Carolyn R Greenwald
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Madeline N Drucker
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Denholm T Feldman
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
| | - Elizabeth S Thrall
- Department of Chemistry and Biochemistry, Fordham University, Bronx, NY 10458, USA
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4
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Laatri S, El Khayari S, Qriouet Z. Exploring the molecular aspect and updating evolutionary approaches to the DNA polymerase enzymes for biotechnological needs: A comprehensive review. Int J Biol Macromol 2024; 276:133924. [PMID: 39033894 DOI: 10.1016/j.ijbiomac.2024.133924] [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: 03/10/2024] [Revised: 07/07/2024] [Accepted: 07/15/2024] [Indexed: 07/23/2024]
Abstract
DNA polymerases are essential enzymes that play a key role in living organisms, as they participate in the synthesis and maintenance of the DNA molecule. The intrinsic properties of these enzymes have been widely observed and studied to understand their functions, activities, and behavior, which has allowed their natural power in DNA synthesis to be exploited in modern biotechnology, to the point of making them true pillars of the field. In this context, the laboratory evolution of these enzymes, either by directed evolution or rational design, has led to the generation of a wide range of new DNA polymerases with novel properties, suitable for a variety of biotechnological needs. In this review, we examine DNA polymerases at the molecular level, their biotechnological use, and their evolutionary methods in relation to the novel properties sought, providing a chronological selection of evolved DNA polymerases cited in the literature that we consider to be of great interest. To our knowledge, this work is the first to bring together the molecular, functional and evolutionary aspects of the DNA polymerase enzyme. We believe it will be of great interest to researchers whose aim is to produce new lines of evolved DNA polymerases.
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Affiliation(s)
- Said Laatri
- Microbiology and Molecular Biology Laboratory, Faculty of Sciences, Mohammed V-Souissi University, Rabat 10100, Morocco.
| | | | - Zidane Qriouet
- Pharmacology and Toxicology Laboratory, Faculty of Medicine and Pharmacy, Mohammed V-Souissi University, Rabat 10100, Morocco
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5
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Cashen BA, Morse M, Rouzina I, Karpel RL, Williams MC. C-terminal Domain of T4 gene 32 Protein Enables Rapid Filament Reorganization and Dissociation. J Mol Biol 2024; 436:168544. [PMID: 38508303 DOI: 10.1016/j.jmb.2024.168544] [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: 01/19/2024] [Revised: 02/27/2024] [Accepted: 03/14/2024] [Indexed: 03/22/2024]
Abstract
Bacteriophage T4 gene 32 protein (gp32) is a single-stranded DNA (ssDNA) binding protein essential for DNA replication. gp32 forms stable protein filaments on ssDNA through cooperative interactions between its core and N-terminal domain. gp32's C-terminal domain (CTD) is believed to primarily help coordinate DNA replication via direct interactions with constituents of the replisome. However, the exact mechanisms of these interactions are not known, and it is unclear how tightly-bound gp32 filaments are readily displaced from ssDNA as required for genomic processing. Here, we utilized truncated gp32 variants to demonstrate a key role of the CTD in regulating gp32 dissociation. Using optical tweezers, we probed the binding and dissociation dynamics of CTD-truncated gp32, *I, to an 8.1 knt ssDNA molecule and compared these measurements with those for full-length gp32. The *I-ssDNA helical filament becomes progressively unwound with increased protein concentration but remains significantly more stable than that of full-length, wild-type gp32. Protein oversaturation, concomitant with filament unwinding, facilitates rapid dissociation of full-length gp32 from across the entire ssDNA segment. In contrast, *I primarily unbinds slowly from only the ends of the cooperative clusters, regardless of the protein density and degree of DNA unwinding. Our results suggest that the CTD may constrain the relative twist angle of proteins within the ssDNA filament such that upon critical unwinding the cooperative interprotein interactions largely vanish, facilitating prompt removal of gp32. We propose a model of CTD-mediated gp32 displacement via internal restructuring of its filament, providing a mechanism for rapid ssDNA clearing during genomic processing.
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Affiliation(s)
- Ben A Cashen
- Department of Physics, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Michael Morse
- Department of Physics, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, Ohio State University, 281 W Lane Avenue, Columbus, OH 43210, USA
| | - Richard L Karpel
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Mark C Williams
- Department of Physics, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
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6
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García-Martínez A, Zinovjev K, Ruiz-Pernía JJ, Tuñón I. Conformational Changes and ATP Hydrolysis in Zika Helicase: The Molecular Basis of a Biomolecular Motor Unveiled by Multiscale Simulations. J Am Chem Soc 2023; 145:24809-24819. [PMID: 37921592 PMCID: PMC10852352 DOI: 10.1021/jacs.3c09015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/30/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
We computationally study the Zika NS3 helicase, a biological motor, using ATP hydrolysis energy for nucleic acid remodeling. Through molecular mechanics and hybrid quantum mechanics/molecular mechanics simulations, we explore the conformational landscape of motif V, a conserved loop connecting the active sites for ATP hydrolysis and nucleic acid binding. ATP hydrolysis, initiated by a meta-phosphate group formation, involves the nucleophilic attack of a water molecule activated by Glu286 proton abstraction. Motif V hydrogen bonds to this water via the Gly415 backbone NH group, assisting hydrolysis. Posthydrolysis, free energy is released when the inorganic phosphate moves away from the coordination shell of the magnesium ion, inducing a significant shift in the conformational landscape of motif V to establish a hydrogen bond between the Gly415 NH group and Glu285. According to our simulations, the Zika NS3 helicase acts as a ratchet biological motor with motif V transitions steered by Gly415's γ-phosphate sensing in the ATPase site.
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Affiliation(s)
| | - Kirill Zinovjev
- Departamento de Química Física, Universidad de Valencia, 46100 Bujassot, Spain
| | | | - Iñaki Tuñón
- Departamento de Química Física, Universidad de Valencia, 46100 Bujassot, Spain
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7
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Heuzé J, Lin YL, Lengronne A, Poli J, Pasero P. Impact of R-loops on oncogene-induced replication stress in cancer cells. C R Biol 2023; 346:95-105. [PMID: 37779381 DOI: 10.5802/crbiol.123] [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: 01/24/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 10/03/2023]
Abstract
Replication stress is an alteration in the progression of replication forks caused by a variety of events of endogenous or exogenous origin. In precancerous lesions, this stress is exacerbated by the deregulation of oncogenic pathways, which notably disrupts the coordination between replication and transcription, and leads to genetic instability and cancer development. It is now well established that transcription can interfere with genome replication in different ways, such as head-on collisions between polymerases, accumulation of positive DNA supercoils or formation of R-loops. These structures form during transcription when nascent RNA reanneals with DNA behind the RNA polymerase, forming a stable DNA:RNA hybrid. In this review, we discuss how these different cotranscriptional processes disrupt the progression of replication forks and how they contribute to genetic instability in cancer cells.
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8
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Cashen BA, Morse M, Rouzina I, Karpel R, Williams M. Dynamic structure of T4 gene 32 protein filaments facilitates rapid noncooperative protein dissociation. Nucleic Acids Res 2023; 51:8587-8605. [PMID: 37449435 PMCID: PMC10484735 DOI: 10.1093/nar/gkad595] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 06/26/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023] Open
Abstract
Bacteriophage T4 gene 32 protein (gp32) is a model single-stranded DNA (ssDNA) binding protein, essential for DNA replication. gp32 forms cooperative filaments on ssDNA through interprotein interactions between its core and N-terminus. However, detailed understanding of gp32 filament structure and organization remains incomplete, particularly for longer, biologically-relevant DNA lengths. Moreover, it is unclear how these tightly-bound filaments dissociate from ssDNA during complementary strand synthesis. We use optical tweezers and atomic force microscopy to probe the structure and binding dynamics of gp32 on long (∼8 knt) ssDNA substrates. We find that cooperative binding of gp32 rigidifies ssDNA while also reducing its contour length, consistent with the ssDNA helically winding around the gp32 filament. While measured rates of gp32 binding and dissociation indicate nM binding affinity, at ∼1000-fold higher protein concentrations gp32 continues to bind into and restructure the gp32-ssDNA filament, leading to an increase in its helical pitch and elongation of the substrate. Furthermore, the oversaturated gp32-ssDNA filament becomes progressively unwound and unstable as observed by the appearance of a rapid, noncooperative protein dissociation phase not seen at lower complex saturation, suggesting a possible mechanism for prompt removal of gp32 from the overcrowded ssDNA in front of the polymerase during replication.
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Affiliation(s)
- Ben A Cashen
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Michael Morse
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA
| | - Richard L Karpel
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Mark C Williams
- Department of Physics, Northeastern University, Boston, MA 02115, USA
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9
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Sonika S, Singh S, Mishra S, Verma S. Toxin-antitoxin systems in bacterial pathogenesis. Heliyon 2023; 9:e14220. [PMID: 37101643 PMCID: PMC10123168 DOI: 10.1016/j.heliyon.2023.e14220] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
Toxin-Antitoxin (TA) systems are abundant in prokaryotes and play an important role in various biological processes such as plasmid maintenance, phage inhibition, stress response, biofilm formation, and dormant persister cell generation. TA loci are abundant in pathogenic intracellular micro-organisms and help in their adaptation to the harsh host environment such as nutrient deprivation, oxidation, immune response, and antimicrobials. Several studies have reported the involvement of TA loci in establishing successful infection, intracellular survival, better colonization, adaptation to host stresses, and chronic infection. Overall, the TA loci play a crucial role in bacterial virulence and pathogenesis. Nonetheless, there are some controversies about the role of TA system in stress response, biofilm and persister formation. In this review, we describe the role of the TA systems in bacterial virulence. We discuss the important features of each type of TA system and the recent discoveries identifying key contributions of TA loci in bacterial pathogenesis.
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10
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Berger MB, Cisneros GA. Distal Mutations in the β-Clamp of DNA Polymerase III* Disrupt DNA Orientation and Affect Exonuclease Activity. J Am Chem Soc 2023; 145:3478-3490. [PMID: 36745735 PMCID: PMC10237177 DOI: 10.1021/jacs.2c11713] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
DNA polymerases are responsible for the replication and repair of DNA found in all DNA-based organisms. DNA Polymerase III is the main replicative polymerase of E. coli and is composed of over 10 proteins. A subset of these proteins (Pol III*) includes the polymerase (α), exonuclease (ϵ), clamp (β), and accessory protein (θ). Mutations of residues in, or around the active site of the catalytic subunits (α and ϵ), can have a significant impact on catalysis. However, the effects of distal mutations in noncatalytic subunits on the activity of catalytic subunits are less well-characterized. Here, we investigate the effects of two Pol III* variants, β-L82E/L82'E and β-L82D/L82'D, on the proofreading reaction catalyzed by ϵ. MD simulations reveal major changes in the dynamics of Pol III*, which extend throughout the complex. These changes are mostly induced by a shift in the position of the DNA substrate inside the β-clamp, although no major structural changes are observed in the protein complex. Quantum mechanics/molecular mechanics (QM/MM) calculations indicate that the β-L82D/L82'D variant has reduced catalytic proficiency due to highly endoergic reaction energies resulting from structural changes in the active site and differences in the electric field at the active site arising from the protein and substrate. Conversely, the β-L82E/L82'E variant is predicted to maintain proofreading activity, exhibiting a similar reaction barrier for nucleotide excision compared with the WT system. However, significant differences in the reaction mechanism are obtained due to the changes induced by the mutations on the β-clamp.
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Affiliation(s)
- Madison B Berger
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - G Andrés Cisneros
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, United States
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11
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Gallitto M, Zhang Z. The evolving tale of Pol2 function. Genes Dev 2023; 37:72-73. [PMID: 36813532 PMCID: PMC10069447 DOI: 10.1101/gad.350527.123] [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] [Indexed: 02/24/2023]
Abstract
DNA replication is complex and highly regulated, and DNA replication errors can lead to human diseases such as cancer. DNA polymerase ε (polε) is a key player in DNA replication and contains a large subunit called POLE, which possesses both a DNA polymerase domain and a 3'-5' exonuclease domain (EXO). Mutations at the EXO domain and other missense mutations on POLE with unknown significance have been detected in a variety of human cancers. Based on cancer genome databases, Meng and colleagues (pp. 74-79) previously identified several missense mutations in POPS (pol2 family-specific catalytic core peripheral subdomain), and mutations at the conserved residues of yeast Pol2 (pol2-REL) showed reduced DNA synthesis and growth. In this issue of Genes & Development, Meng and colleagues (pp. 74-79) found unexpectedly that mutations at the EXO domain rescue the growth defects of pol2-REL. They further discovered that EXO-mediated polymerase backtracking impedes forward movement of the enzyme when POPS is defective, revealing a novel interplay between the EXO domain and POPS of Pol2 for efficient DNA synthesis. Additional molecular insight into this interplay will likely inform the impact of cancer-associated mutations found in both the EXO domain and POPS on tumorigenesis and uncover future novel therapeutic strategies.
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Affiliation(s)
- Matthew Gallitto
- Institute for Cancer Genetics, Department of Pediatrics, Department of Genetics and Development, Irving Cancer Research Center, Columbia University, New York, New York 10032, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Department of Pediatrics, Department of Genetics and Development, Irving Cancer Research Center, Columbia University, New York, New York 10032, USA
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12
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Abundant and cosmopolitan lineage of cyanopodoviruses lacking a DNA polymerase gene. THE ISME JOURNAL 2023; 17:252-262. [PMID: 36357781 PMCID: PMC9860041 DOI: 10.1038/s41396-022-01340-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 10/23/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022]
Abstract
Cyanopodoviruses affect the mortality and population dynamics of the unicellular picocyanobacteria Prochlorococcus and Synechococcus, the dominant primary producers in the oceans. Known cyanopodoviruses all contain the DNA polymerase gene (DNA pol) that is important for phage DNA replication and widely used in field quantification and diversity studies. However, we isolated 18 cyanopodoviruses without identifiable DNA pol. They form a new MPP-C clade that was separated from the existing MPP-A, MPP-B, and P-RSP2 clades. The MPP-C phages have the smallest genomes (37.3-37.9 kb) among sequenced cyanophages, and show longer latent periods than the MPP-B phages. Metagenomic reads of both clades are highly abundant in surface waters, but the MPP-C phages show higher relative abundance in surface waters than in deeper waters, while MPP-B phages have higher relative abundance in deeper waters. Our study reveals that cyanophages with distinct genomic contents and infection kinetics can exhibit different depth profiles in the oceans.
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13
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Raducanu VS, Tehseen M, Al-Amodi A, Joudeh LI, De Biasio A, Hamdan SM. Mechanistic investigation of human maturation of Okazaki fragments reveals slow kinetics. Nat Commun 2022; 13:6973. [PMID: 36379932 PMCID: PMC9666535 DOI: 10.1038/s41467-022-34751-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 11/04/2022] [Indexed: 11/16/2022] Open
Abstract
The final steps of lagging strand synthesis induce maturation of Okazaki fragments via removal of the RNA primers and ligation. Iterative cycles between Polymerase δ (Polδ) and Flap endonuclease-1 (FEN1) remove the primer, with an intermediary nick structure generated for each cycle. Here, we show that human Polδ is inefficient in releasing the nick product from FEN1, resulting in non-processive and remarkably slow RNA removal. Ligase 1 (Lig1) can release the nick from FEN1 and actively drive the reaction toward ligation. These mechanisms are coordinated by PCNA, which encircles DNA, and dynamically recruits Polδ, FEN1, and Lig1 to compete for their substrates. Our findings call for investigating additional pathways that may accelerate RNA removal in human cells, such as RNA pre-removal by RNase Hs, which, as demonstrated herein, enhances the maturation rate ~10-fold. They also suggest that FEN1 may attenuate the various activities of Polδ during DNA repair and recombination.
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Affiliation(s)
- Vlad-Stefan Raducanu
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Muhammad Tehseen
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Amani Al-Amodi
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Luay I Joudeh
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Alfredo De Biasio
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia.
| | - Samir M Hamdan
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia.
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14
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Du H, Jolly A, Grochowski CM, Yuan B, Dawood M, Jhangiani SN, Li H, Muzny D, Fatih JM, Coban-Akdemir Z, Carlin ME, Scheuerle AE, Witzl K, Posey JE, Pendleton M, Harrington E, Juul S, Hastings PJ, Bi W, Gibbs RA, Sedlazeck FJ, Lupski JR, Carvalho CMB, Liu P. The multiple de novo copy number variant (MdnCNV) phenomenon presents with peri-zygotic DNA mutational signatures and multilocus pathogenic variation. Genome Med 2022; 14:122. [PMID: 36303224 PMCID: PMC9609164 DOI: 10.1186/s13073-022-01123-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 10/10/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The multiple de novo copy number variant (MdnCNV) phenotype is described by having four or more constitutional de novo CNVs (dnCNVs) arising independently throughout the human genome within one generation. It is a rare peri-zygotic mutational event, previously reported to be seen once in every 12,000 individuals referred for genome-wide chromosomal microarray analysis due to congenital abnormalities. These rare families provide a unique opportunity to understand the genetic factors of peri-zygotic genome instability and the impact of dnCNV on human diseases. METHODS Chromosomal microarray analysis (CMA), array-based comparative genomic hybridization, short- and long-read genome sequencing (GS) were performed on the newly identified MdnCNV family to identify de novo mutations including dnCNVs, de novo single-nucleotide variants (dnSNVs), and indels. Short-read GS was performed on four previously published MdnCNV families for dnSNV analysis. Trio-based rare variant analysis was performed on the newly identified individual and four previously published MdnCNV families to identify potential genetic etiologies contributing to the peri-zygotic genomic instability. Lin semantic similarity scores informed quantitative human phenotype ontology analysis on three MdnCNV families to identify gene(s) driving or contributing to the clinical phenotype. RESULTS In the newly identified MdnCNV case, we revealed eight de novo tandem duplications, each ~ 1 Mb, with microhomology at 6/8 breakpoint junctions. Enrichment of de novo single-nucleotide variants (SNV; 6/79) and de novo indels (1/12) was found within 4 Mb of the dnCNV genomic regions. An elevated post-zygotic SNV mutation rate was observed in MdnCNV families. Maternal rare variant analyses identified three genes in distinct families that may contribute to the MdnCNV phenomenon. Phenotype analysis suggests that gene(s) within dnCNV regions contribute to the observed proband phenotype in 3/3 cases. CNVs in two cases, a contiguous gene duplication encompassing PMP22 and RAI1 and another duplication affecting NSD1 and SMARCC2, contribute to the clinically observed phenotypic manifestations. CONCLUSIONS Characteristic features of dnCNVs reported here are consistent with a microhomology-mediated break-induced replication (MMBIR)-driven mechanism during the peri-zygotic period. Maternal genetic variants in DNA repair genes potentially contribute to peri-zygotic genomic instability. Variable phenotypic features were observed across a cohort of three MdnCNV probands, and computational quantitative phenotyping revealed that two out of three had evidence for the contribution of more than one genetic locus to the proband's phenotype supporting the hypothesis of de novo multilocus pathogenic variation (MPV) in those families.
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Affiliation(s)
- Haowei Du
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Angad Jolly
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Christopher M Grochowski
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Bo Yuan
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratory, Houston, TX, 77021, USA
- Seattle Children's Hospital, Seattle, WA, 98105, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Moez Dawood
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - He Li
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Donna Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Zeynep Coban-Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Mary Esther Carlin
- Division of Genetics and Metabolism, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Angela E Scheuerle
- Division of Genetics and Metabolism, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Division of Genetics Diagnostics, Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Karin Witzl
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, 1000, Ljubljana, Slovenia
- Medical Faculty, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | | | | | - Sissel Juul
- Oxford Nanopore Technologies Inc, New York, NY, 10013, USA
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, BCM, Houston, TX, 77030, USA
| | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratory, Houston, TX, 77021, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Fritz J Sedlazeck
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Texas Children's Hospital, Houston, TX, 77030, USA.
| | - Claudia M B Carvalho
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Pacific Northwest Research Institute, 720 Broadway, Seattle, WA, 98122, USA.
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Baylor Genetics Laboratory, Houston, TX, 77021, USA.
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15
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Yappert R, Peters B. Processive Depolymerization Catalysts: A Population Balance Model for Chemistry’s “While” Loop. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Ryan Yappert
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Baron Peters
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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16
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Post-Translational Modifications of PCNA: Guiding for the Best DNA Damage Tolerance Choice. J Fungi (Basel) 2022; 8:jof8060621. [PMID: 35736104 PMCID: PMC9225081 DOI: 10.3390/jof8060621] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/01/2022] [Accepted: 06/07/2022] [Indexed: 02/01/2023] Open
Abstract
The sliding clamp PCNA is a multifunctional homotrimer mainly linked to DNA replication. During this process, cells must ensure an accurate and complete genome replication when constantly challenged by the presence of DNA lesions. Post-translational modifications of PCNA play a crucial role in channeling DNA damage tolerance (DDT) and repair mechanisms to bypass unrepaired lesions and promote optimal fork replication restart. PCNA ubiquitination processes trigger the following two main DDT sub-pathways: Rad6/Rad18-dependent PCNA monoubiquitination and Ubc13-Mms2/Rad5-mediated PCNA polyubiquitination, promoting error-prone translation synthesis (TLS) or error-free template switch (TS) pathways, respectively. However, the fork protection mechanism leading to TS during fork reversal is still poorly understood. In contrast, PCNA sumoylation impedes the homologous recombination (HR)-mediated salvage recombination (SR) repair pathway. Focusing on Saccharomyces cerevisiae budding yeast, we summarized PCNA related-DDT and repair mechanisms that coordinately sustain genome stability and cell survival. In addition, we compared PCNA sequences from various fungal pathogens, considering recent advances in structural features. Importantly, the identification of PCNA epitopes may lead to potential fungal targets for antifungal drug development.
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17
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Bhardwaj VK, Oakley A, Purohit R. Mechanistic behavior and subtle key events during DNA clamp opening and closing in T4 bacteriophage. Int J Biol Macromol 2022; 208:11-19. [PMID: 35276295 DOI: 10.1016/j.ijbiomac.2022.03.021] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 01/15/2023]
Abstract
Clamp loaders ensure processive DNA replication by loading the toroidal shaped sliding clamps onto the DNA. The sliding clamps serve as a platform for the attachment of polymerases and several other proteins associated with the regulation of various cellular processes. Clamp loaders are fascinating as nanomachines that engage in protein-protein and protein-DNA interactions. The loading mechanism of the clamp around dsDNA at the atomic level has not yet been fully explored. We performed microsecond timescale molecular dynamics simulations to reveal the dynamics of two different intermediate complexes involved in loading of the clamps around DNA. We conducted various time-dependent MD-driven analyses including the highly robust Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) calculations to observe changes in the structural elements of the clamp loader-clamp-DNA complexes in open and closed states. Our studies revealed the structural consequences of ATP hydrolysis events at different subunits of the clamp loader. This study would help in a better understanding of the clamp loading mechanism and would allow tackling various complications that might arise due to irregularities in this process.
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Affiliation(s)
- Vijay Kumar Bhardwaj
- Structural Bioinformatics Lab, CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, HP, 176061, India; Biotechnology Division, CSIR-IHBT, Palampur, HP 176061, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Aaron Oakley
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, and Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia
| | - Rituraj Purohit
- Structural Bioinformatics Lab, CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, HP, 176061, India; Biotechnology Division, CSIR-IHBT, Palampur, HP 176061, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India.
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18
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Dahl JM, Thomas N, Tracy MA, Hearn BL, Perera L, Kennedy SR, Herr AJ, Kunkel TA. Probing the mechanisms of two exonuclease domain mutators of DNA polymerase ϵ. Nucleic Acids Res 2022; 50:962-974. [PMID: 35037018 DOI: 10.1093/nar/gkab1255] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 11/21/2021] [Accepted: 12/08/2021] [Indexed: 11/15/2022] Open
Abstract
We report the properties of two mutations in the exonuclease domain of the Saccharomyces cerevisiae DNA polymerase ϵ. One, pol2-Y473F, increases the mutation rate by about 20-fold, similar to the catalytically dead pol2-D290A/E290A mutant. The other, pol2-N378K, is a stronger mutator. Both retain the ability to excise a nucleotide from double-stranded DNA, but with impaired activity. pol2-Y473F degrades DNA poorly, while pol2-N378K degrades single-stranded DNA at an elevated rate relative to double-stranded DNA. These data suggest that pol2-Y473F reduces the capacity of the enzyme to perform catalysis in the exonuclease active site, while pol2-N378K impairs partitioning to the exonuclease active site. Relative to wild-type Pol ϵ, both variants decrease the dNTP concentration required to elicit a switch between proofreading and polymerization by more than an order of magnitude. While neither mutation appears to alter the sequence specificity of polymerization, the N378K mutation stimulates polymerase activity, increasing the probability of incorporation and extension of a mismatch. Considered together, these data indicate that impairing the primer strand transfer pathway required for proofreading increases the probability of common mutations by Pol ϵ, elucidating the association of homologous mutations in human DNA polymerase ϵ with cancer.
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Affiliation(s)
- Joseph M Dahl
- Genome Integrity Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, DHHS, Research Triangle Park, NC 27709, USA
| | - Natalie Thomas
- Genome Integrity Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, DHHS, Research Triangle Park, NC 27709, USA
| | - Maxwell A Tracy
- Department of Laboratory Medicine and Pathology, UW Medicine, Seattle, WA 98195, USA
| | - Brady L Hearn
- Department of Laboratory Medicine and Pathology, UW Medicine, Seattle, WA 98195, USA
| | - Lalith Perera
- Genome Integrity Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, DHHS, Research Triangle Park, NC 27709, USA
| | - Scott R Kennedy
- Department of Laboratory Medicine and Pathology, UW Medicine, Seattle, WA 98195, USA
| | - Alan J Herr
- Department of Laboratory Medicine and Pathology, UW Medicine, Seattle, WA 98195, USA
| | - Thomas A Kunkel
- Genome Integrity Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, DHHS, Research Triangle Park, NC 27709, USA
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19
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Lata K, Vishwakarma J, Kumar S, Khanam T, Ramachandran R. Mycobacterium tuberculosis Endonuclease VIII 2 (Nei2) forms a prereplicative BER complex with DnaN: Identification, characterization, and disruption of complex formation. Mol Microbiol 2021; 117:320-333. [PMID: 34820919 DOI: 10.1111/mmi.14848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/18/2021] [Accepted: 11/19/2021] [Indexed: 12/12/2022]
Abstract
Mycobacterium tuberculosis Nei2 (Rv3297) is a BER glycosylase that removes oxidized base lesions from ssDNA and replication fork-mimicking substrates. We show that Endonuclease VIII 2 (Nei2) forms a BER complex with the β-clamp (DnaN, Rv0002) with a KD of 170 nM. The Nei2-β-clamp interactions enhance Nei2's activities up to several folds. SEC analysis shows that one molecule of Nei2 binds to a single β-clamp dimer. Nei2 interacts with subsites I and II of the β-clamp via a noncanonical 223 QGCRRCGTLIAY239 Clamp Interacting Protein (CIP) motif in the C-terminal zinc-finger domain, which was previously shown by us to be dispensable for intrinsic Nei2 activity. The 12-mer peptide alone exhibited a KD of 10.28 nM, suggesting that the motif is a key mediator of Nei2-β-clamp interactions. Finally, we identified inhibitors of Nei2-β-clamp interactions using rational methods, in vitro disruption, and SPR assays after querying a database of natural products. We found that Tubulosine, Fumitremorgin C, Toyocamycin, and Aleuritic acid exhibit IC50 values of 94.47, 83.49, 109.7, and 71.49 µM, respectively. They act by disrupting Nei2-β-clamp interactions and do not affect intrinsic Nei2 activity. Among other things, the present study gives insights into the role of Nei2 in bacterial prereplicative BER.
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Affiliation(s)
- Kiran Lata
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Jyoti Vishwakarma
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Sanjay Kumar
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Taran Khanam
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Ravishankar Ramachandran
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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20
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Bocanegra R, Plaza G A I, Ibarra B. In vitro single-molecule manipulation studies of viral DNA replication. Enzymes 2021; 49:115-148. [PMID: 34696830 DOI: 10.1016/bs.enz.2021.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Faithfull replication of genomic information relies on the coordinated activity of the multi-protein machinery known as the replisome. Several constituents of the replisome operate as molecular motors that couple thermal and chemical energy to a mechanical task. Over the last few decades, in vitro single-molecule manipulation techniques have been used to monitor and manipulate mechanically the activities of individual molecular motors involved in DNA replication with nanometer, millisecond, and picoNewton resolutions. These studies have uncovered the real-time kinetics of operation of these biological systems, the nature of their transient intermediates, and the processes by which they convert energy to work (mechano-chemistry), ultimately providing new insights into their inner workings of operation not accessible by ensemble assays. In this chapter, we describe two of the most widely used single-molecule manipulation techniques for the study of DNA replication, optical and magnetic tweezers, and their application in the study of the activities of proteins involved in viral DNA replication.
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Affiliation(s)
- Rebeca Bocanegra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Ismael Plaza G A
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain.
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21
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Structure of an open conformation of T7 DNA polymerase reveals novel structural features regulating primer-template stabilization at the polymerization active site. Biochem J 2021; 478:2665-2679. [PMID: 34160020 DOI: 10.1042/bcj20200922] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 01/25/2023]
Abstract
The crystal structure of full-length T7 DNA polymerase in complex with its processivity factor thioredoxin and double-stranded DNA in the polymerization active site exhibits two novel structural motifs in family-A DNA polymerases: an extended β-hairpin at the fingers subdomain, that interacts with the DNA template strand downstream the primer-terminus, and a helix-loop-helix motif (insertion1) located between residues 102 to 122 in the exonuclease domain. The extended β-hairpin is involved in nucleotide incorporation on substrates with 5'-overhangs longer than 2 nt, suggesting a role in stabilizing the template strand into the polymerization domain. Our biochemical data reveal that insertion1 of the exonuclease domain makes stabilizing interactions that facilitate proofreading by shuttling the primer strand into the exonuclease active site. Overall, our studies evidence conservation of the 3'-5' exonuclease domain fold between family-A DNA polymerases and highlight the modular architecture of T7 DNA polymerase. Our data suggest that the intercalating β-hairpin guides the template-strand into the polymerization active site after the T7 primase-helicase unwinds the DNA double helix ameliorating the formation of secondary structures and decreasing the appearance of indels.
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22
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Soriano I, Vazquez E, De Leon N, Bertrand S, Heitzer E, Toumazou S, Bo Z, Palles C, Pai CC, Humphrey TC, Tomlinson I, Cotterill S, Kearsey SE. Expression of the cancer-associated DNA polymerase ε P286R in fission yeast leads to translesion synthesis polymerase dependent hypermutation and defective DNA replication. PLoS Genet 2021; 17:e1009526. [PMID: 34228709 PMCID: PMC8284607 DOI: 10.1371/journal.pgen.1009526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 07/16/2021] [Accepted: 06/11/2021] [Indexed: 12/15/2022] Open
Abstract
Somatic and germline mutations in the proofreading domain of the replicative DNA polymerase ε (POLE-exonuclease domain mutations, POLE-EDMs) are frequently found in colorectal and endometrial cancers and, occasionally, in other tumours. POLE-associated cancers typically display hypermutation, and a unique mutational signature, with a predominance of C > A transversions in the context TCT and C > T transitions in the context TCG. To understand better the contribution of hypermutagenesis to tumour development, we have modelled the most recurrent POLE-EDM (POLE-P286R) in Schizosaccharomyces pombe. Whole-genome sequencing analysis revealed that the corresponding pol2-P287R allele also has a strong mutator effect in vivo, with a high frequency of base substitutions and relatively few indel mutations. The mutations are equally distributed across different genomic regions, but in the immediate vicinity there is an asymmetry in AT frequency. The most abundant base-pair changes are TCT > TAT transversions and, in contrast to human mutations, TCG > TTG transitions are not elevated, likely due to the absence of cytosine methylation in fission yeast. The pol2-P287R variant has an increased sensitivity to elevated dNTP levels and DNA damaging agents, and shows reduced viability on depletion of the Pfh1 helicase. In addition, S phase is aberrant and RPA foci are elevated, suggestive of ssDNA or DNA damage, and the pol2-P287R mutation is synthetically lethal with rad3 inactivation, indicative of checkpoint activation. Significantly, deletion of genes encoding some translesion synthesis polymerases, most notably Pol κ, partially suppresses pol2-P287R hypermutation, indicating that polymerase switching contributes to this phenotype.
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Affiliation(s)
- Ignacio Soriano
- ZRAB, University of Oxford, Oxford, United Kingdom
- Edinburgh Cancer Research Centre, Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Enrique Vazquez
- Genomics Unit, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Nagore De Leon
- ZRAB, University of Oxford, Oxford, United Kingdom
- Edinburgh Cancer Research Centre, Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | | | - Ellen Heitzer
- Institute of Human Genetics, Diagnostic & Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria
| | - Sophia Toumazou
- ZRAB, University of Oxford, Oxford, United Kingdom
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Zhihan Bo
- ZRAB, University of Oxford, Oxford, United Kingdom
| | - Claire Palles
- Gastrointestinal Cancer Genetics Laboratory, Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Chen-Chun Pai
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Timothy C. Humphrey
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Ian Tomlinson
- Edinburgh Cancer Research Centre, Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Sue Cotterill
- St. George’s, University of London, Cranmer Terrace, Tooting, London, United Kingdom
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23
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Jarillo J, Ibarra B, Cao-García FJ. DNA replication: In vitro single-molecule manipulation data analysis and models. Comput Struct Biotechnol J 2021; 19:3765-3778. [PMID: 34285777 PMCID: PMC8267548 DOI: 10.1016/j.csbj.2021.06.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/05/2022] Open
Abstract
Data analysis allows to extract information from the noisy single-molecule data. Models provide insight in the underlying biochemical processes. Ligands can activate or inhibit DNA replication and DNA unwinding.
DNA replication is a key biochemical process of the cell cycle. In the last years, analysis of in vitro single-molecule DNA replication events has provided new information that cannot be obtained with ensembles studies. Here, we introduce crucial techniques for the proper analysis and modelling of DNA replication in vitro single-molecule manipulation data. Specifically, we review some of the main methods to analyze and model the real-time kinetics of the two main molecular motors of the replisome: DNA polymerase and DNA helicase. Our goal is to facilitate access to and understanding of these techniques to promotetheir use in the study of DNA replication at the single-molecule level. A proper analysis of single-molecule data is crucial to obtain a detailed picture of, among others, the kinetics rates, equilibrium contants and conformational changes of the system under study. The techniques presented here have been used or can be adapted to study the operation of other proteins involved in nucleic acids metabolism.
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Affiliation(s)
- Javier Jarillo
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain
| | - Francisco Javier Cao-García
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain.,Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
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24
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Abstract
In all cell types, a multi-protein machinery is required to accurately duplicate the large duplex DNA genome. This central life process requires five core replisome factors in all cellular life forms studied thus far. Unexpectedly, three of the five core replisome factors have no common ancestor between bacteria and eukaryotes. Accordingly, the replisome machines of bacteria and eukaryotes have important distinctions in the way that they are organized and function. This chapter outlines the major replication proteins that perform DNA duplication at replication forks, with particular attention to differences and similarities in the strategies used by eukaryotes and bacteria.
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Affiliation(s)
- Nina Y Yao
- DNA Replication Laboratory, The Rockefeller University, New York, USA, 10065
| | - Michael E O'Donnell
- DNA Replication Laboratory, The Rockefeller University, New York, USA, 10065. .,Howard Hughes Medical Institute, The Rockefeller University, New York, USA, 10065.
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25
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Amanat S, Gallego-Martinez A, Lopez-Escamez JA. Genetic Inheritance and Its Contribution to Tinnitus. Curr Top Behav Neurosci 2021; 51:29-47. [PMID: 32705497 DOI: 10.1007/7854_2020_155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Tinnitus is the abnormal perception of sound that affects more than 15% of adult population around the globe. Severe tinnitus is considered a complex disorder that arises as result of the interaction of genetic and environmental factors, and it is associated with several comorbidities such as hearing loss, anxiety, and insomnia. We begin this review with an introduction to human molecular genetics and the role of genetic variation on the inheritance. There are some genetic reports on tinnitus heritability including concordance studies in twins and adoptees or aggregation in families providing some evidence for familial aggregation in patients with severe tinnitus and high concordance in monozygotic twins with bilateral tinnitus. So, sex differences in familial aggregation and heritability of bilateral tinnitus suggest a potential sexual dimorphism in tinnitus inheritance.Molecular genetic studies have been demonstrated to be a useful tool to understand the role of genetic variation in rare diseases and complex disorders. The reported associations in common variants in neurotrophic factors such as GDNF, BDNF, or potassium channels genes were underpowered, and the lack of replication questions these findings. Although candidate gene approaches have failed in replicating these genetic associations, the development of high throughput sequencing technology and the selection of extreme phenotypes are strategies that will allow the clinicians and researchers to combine genetic information with clinical data to implement a personalized diagnosis and therapy in patients with tinnitus.
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Affiliation(s)
- Sana Amanat
- Otology and Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer, University of Granada, Junta de Andalucía, PTS, Granada, Spain
| | - Alvaro Gallego-Martinez
- Otology and Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer, University of Granada, Junta de Andalucía, PTS, Granada, Spain
| | - Jose A Lopez-Escamez
- Otology and Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer, University of Granada, Junta de Andalucía, PTS, Granada, Spain.
- Department of Otolaryngology, Instituto de Investigación Biosanitaria ibs.GRANADA, Hospital Universitario Virgen de las Nieves, Universidad de Granada, Granada, Spain.
- Division of Otolaryngology, Department of Surgery, Universidad de Granada, Granada, Spain.
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26
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Lee KY, Park SH. Eukaryotic clamp loaders and unloaders in the maintenance of genome stability. Exp Mol Med 2020; 52:1948-1958. [PMID: 33339954 PMCID: PMC8080817 DOI: 10.1038/s12276-020-00533-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/08/2020] [Accepted: 10/12/2020] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic sliding clamp proliferating cell nuclear antigen (PCNA) plays a critical role as a processivity factor for DNA polymerases and as a binding and acting platform for many proteins. The ring-shaped PCNA homotrimer and the DNA damage checkpoint clamp 9-1-1 are loaded onto DNA by clamp loaders. PCNA can be loaded by the pentameric replication factor C (RFC) complex and the CTF18-RFC-like complex (RLC) in vitro. In cells, each complex loads PCNA for different purposes; RFC-loaded PCNA is essential for DNA replication, while CTF18-RLC-loaded PCNA participates in cohesion establishment and checkpoint activation. After completing its tasks, PCNA is unloaded by ATAD5 (Elg1 in yeast)-RLC. The 9-1-1 clamp is loaded at DNA damage sites by RAD17 (Rad24 in yeast)-RLC. All five RFC complex components, but none of the three large subunits of RLC, CTF18, ATAD5, or RAD17, are essential for cell survival; however, deficiency of the three RLC proteins leads to genomic instability. In this review, we describe recent findings that contribute to the understanding of the basic roles of the RFC complex and RLCs and how genomic instability due to deficiency of the three RLCs is linked to the molecular and cellular activity of RLC, particularly focusing on ATAD5 (Elg1). The attachment and removal of clamp proteins that encircle DNA as it is copied and assist its replication and maintenance is mediated by DNA clamp loader and unloader proteins; defects in loading and unloading can increase the rate of damaging mutations. Kyoo-young Lee and Su Hyung Park at the Institute for Basic Science in Ulsan, South Korea, review current understanding of the activity of clamp loading and unloading proteins. They examine research on the proteins in eukaryotic cells, those containing a cell nucleus, making their discussion relevant to understanding the stability of the human genome. They focus particular attention on a protein called ATAD5, which is involved in unloading the clamp proteins. Deficiencies in ATAD5 function have been implicated in genetic instability that might lead to several different types of cancer.
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Affiliation(s)
- Kyoo-Young Lee
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, Korea.
| | - Su Hyung Park
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, Korea
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27
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Stout K, Peters TPJ, Mabesoone MFJ, Visschers FLL, Meijer EM, Klop J, van den Berg J, White PB, Rowan AE, Nolte RJM, Elemans JAAW. Double Porphyrin Cage Compounds. European J Org Chem 2020; 2020:7087-7100. [PMID: 33380897 PMCID: PMC7756431 DOI: 10.1002/ejoc.202001211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Indexed: 01/01/2023]
Abstract
The synthesis and characterization of double porphyrin cage compounds are described. They consist of two porphyrins that are each attached to a diphenylglycoluril-based clip molecule via four ethyleneoxy spacers, and are linked together by a single alkyl chain using "click"-chemistry. Following a newly developed multistep synthesis procedure we report three of these double porphyrin cages, linked by spacers of different lengths, i.e. 3, 5, and 11 carbon atoms. The structures of the double porphyrin cages were fully characterized by NMR, which revealed that they consist of mixtures of two diastereoisomers. Their zinc derivatives are capable of forming sandwich-like complexes with the ditopic ligand 1,4-diazabicyclo[2,2,2]octane (dabco).
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Affiliation(s)
- Kathleen Stout
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Theo P. J. Peters
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Mathijs F. J. Mabesoone
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Fabian L. L. Visschers
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Eline M. Meijer
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Joëlle‐Rose Klop
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Jeroen van den Berg
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Paul B. White
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Alan E. Rowan
- Australian Institute for Bioengineering and Nanotechnology (AIBN), Corner College and Cooper Rds (Bldg 75)The University of Queensland4072Brisbane QldAustralia
| | - Roeland J. M. Nolte
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
| | - Johannes A. A. W. Elemans
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525AJ NijmegenThe Netherlands
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28
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Pavlov YI, Zhuk AS, Stepchenkova EI. DNA Polymerases at the Eukaryotic Replication Fork Thirty Years after: Connection to Cancer. Cancers (Basel) 2020; 12:E3489. [PMID: 33255191 PMCID: PMC7760166 DOI: 10.3390/cancers12123489] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/13/2020] [Accepted: 11/13/2020] [Indexed: 12/13/2022] Open
Abstract
Recent studies on tumor genomes revealed that mutations in genes of replicative DNA polymerases cause a predisposition for cancer by increasing genome instability. The past 10 years have uncovered exciting details about the structure and function of replicative DNA polymerases and the replication fork organization. The principal idea of participation of different polymerases in specific transactions at the fork proposed by Morrison and coauthors 30 years ago and later named "division of labor," remains standing, with an amendment of the broader role of polymerase δ in the replication of both the lagging and leading DNA strands. However, cancer-associated mutations predominantly affect the catalytic subunit of polymerase ε that participates in leading strand DNA synthesis. We analyze how new findings in the DNA replication field help elucidate the polymerase variants' effects on cancer.
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Affiliation(s)
- Youri I. Pavlov
- Eppley Institute for Research in Cancer and Allied Diseases and Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Department of Genetics and Biotechnology, Saint-Petersburg State University, 199034 Saint Petersburg, Russia;
| | - Anna S. Zhuk
- International Laboratory of Computer Technologies, ITMO University, 197101 Saint Petersburg, Russia;
| | - Elena I. Stepchenkova
- Department of Genetics and Biotechnology, Saint-Petersburg State University, 199034 Saint Petersburg, Russia;
- Laboratory of Mutagenesis and Genetic Toxicology, Vavilov Institute of General Genetics, Saint-Petersburg Branch, Russian Academy of Sciences, 199034 Saint Petersburg, Russia
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29
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Potassium Glutamate and Glycine Betaine Induce Self-Assembly of the PCNA and β-Sliding Clamps. Biophys J 2020; 120:73-85. [PMID: 33221249 DOI: 10.1016/j.bpj.2020.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022] Open
Abstract
Sliding clamps are oligomeric ring-shaped proteins that increase the efficiency of DNA replication. The stability of the Escherichia coli β-clamp, a homodimer, is particularly remarkable. The dissociation equilibrium constant of the β-clamp is of the order of 10 pM in buffers of moderate ionic strength. Coulombic electrostatic interactions have been shown to contribute to this remarkable stability. Increasing NaCl concentration in the assay buffer results in decreased dimer stability and faster subunit dissociation kinetics in a way consistent with simple charge-screening models. Here, we examine non-Coulombic ionic effects on the oligomerization properties of sliding clamps. We determined relative diffusion coefficients of two sliding clamps using fluorescence correlation spectroscopy. Replacing NaCl by KGlu, the primary cytoplasmic salt in E. coli, results in a decrease of the diffusion coefficient of these proteins consistent with the formation of protein assemblies. The UV-vis spectrum of the β-clamp labeled with tetramethylrhodamine shows the characteristic absorption band of dimers of rhodamine when KGlu is present in the buffer. This suggests that KGlu induces the formation of assemblies that involve two or more rings stacked face-to-face. Results can be quantitatively explained on the basis of unfavorable interactions between KGlu and the functional groups on the protein surface, which drive biomolecular processes that bury exposed surface. Similar results were obtained with the Saccharomyces cerevisiae PCNA sliding clamp, suggesting that KGlu effects are not specific to the β-clamp. Clamp association is also promoted by glycine betaine, a zwitterionic compound that accumulates intracellularly when E. coli is exposed to high concentrations of extracellular solute. Possible biological implications are discussed.
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30
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Novel Antibiotics Targeting Bacterial Replicative DNA Polymerases. Antibiotics (Basel) 2020; 9:antibiotics9110776. [PMID: 33158178 PMCID: PMC7694242 DOI: 10.3390/antibiotics9110776] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/31/2020] [Accepted: 11/02/2020] [Indexed: 12/15/2022] Open
Abstract
Multidrug resistance is a worldwide problem that is an increasing threat to global health. Therefore, the development of new antibiotics that inhibit novel targets is of great urgency. Some of the most successful antibiotics inhibit RNA transcription, RNA translation, and DNA replication. Transcription and translation are inhibited by directly targeting the RNA polymerase or ribosome, respectively. DNA replication, in contrast, is inhibited indirectly through targeting of DNA gyrases, and there are currently no antibiotics that inhibit DNA replication by directly targeting the replisome. This contrasts with antiviral therapies where the viral replicases are extensively targeted. In the last two decades there has been a steady increase in the number of compounds that target the bacterial replisome. In particular a variety of inhibitors of the bacterial replicative polymerases PolC and DnaE have been described, with one of the DNA polymerase inhibitors entering clinical trials for the first time. In this review we will discuss past and current work on inhibition of DNA replication, and the potential of bacterial DNA polymerase inhibitors in particular as attractive targets for a new generation of antibiotics.
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31
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Dodd T, Botto M, Paul F, Fernandez-Leiro R, Lamers MH, Ivanov I. Polymerization and editing modes of a high-fidelity DNA polymerase are linked by a well-defined path. Nat Commun 2020; 11:5379. [PMID: 33097731 PMCID: PMC7584608 DOI: 10.1038/s41467-020-19165-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 10/02/2020] [Indexed: 12/27/2022] Open
Abstract
Proofreading by replicative DNA polymerases is a fundamental mechanism ensuring DNA replication fidelity. In proofreading, mis-incorporated nucleotides are excised through the 3'-5' exonuclease activity of the DNA polymerase holoenzyme. The exonuclease site is distal from the polymerization site, imposing stringent structural and kinetic requirements for efficient primer strand transfer. Yet, the molecular mechanism of this transfer is not known. Here we employ molecular simulations using recent cryo-EM structures and biochemical analyses to delineate an optimal free energy path connecting the polymerization and exonuclease states of E. coli replicative DNA polymerase Pol III. We identify structures for all intermediates, in which the transitioning primer strand is stabilized by conserved Pol III residues along the fingers, thumb and exonuclease domains. We demonstrate switching kinetics on a tens of milliseconds timescale and unveil a complete pol-to-exo switching mechanism, validated by targeted mutational experiments.
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Affiliation(s)
- Thomas Dodd
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
- Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Margherita Botto
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Fabian Paul
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL, USA
| | | | - Meindert H Lamers
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Ivaylo Ivanov
- Department of Chemistry, Georgia State University, Atlanta, GA, USA.
- Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA.
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32
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Cardano M, Tribioli C, Prosperi E. Targeting Proliferating Cell Nuclear Antigen (PCNA) as an Effective Strategy to Inhibit Tumor Cell Proliferation. Curr Cancer Drug Targets 2020; 20:240-252. [PMID: 31951183 DOI: 10.2174/1568009620666200115162814] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/12/2019] [Accepted: 12/18/2019] [Indexed: 12/20/2022]
Abstract
Targeting highly proliferating cells is an important issue for many types of aggressive tumors. Proliferating Cell Nuclear Antigen (PCNA) is an essential protein that participates in a variety of processes of DNA metabolism, including DNA replication and repair, chromatin organization and transcription and sister chromatid cohesion. In addition, PCNA is involved in cell survival, and possibly in pathways of energy metabolism, such as glycolysis. Thus, the possibility of targeting this protein for chemotherapy against highly proliferating malignancies is under active investigation. Currently, approaches to treat cells with agents targeting PCNA rely on the use of small molecules or on peptides that either bind to PCNA, or act as a competitor of interacting partners. Here, we describe the status of the art in the development of agents targeting PCNA and discuss their application in different types of tumor cell lines and in animal model systems.
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Affiliation(s)
- Miriana Cardano
- Istituto di Genetica Molecolare del C.N.R. "Luca Cavalli-Sforza", Pavia- 27100, Italy
| | - Carla Tribioli
- Istituto di Genetica Molecolare del C.N.R. "Luca Cavalli-Sforza", Pavia- 27100, Italy
| | - Ennio Prosperi
- Istituto di Genetica Molecolare del C.N.R. "Luca Cavalli-Sforza", Pavia- 27100, Italy
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33
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Yoo J, Winogradoff D, Aksimentiev A. Molecular dynamics simulations of DNA-DNA and DNA-protein interactions. Curr Opin Struct Biol 2020; 64:88-96. [PMID: 32682257 DOI: 10.1016/j.sbi.2020.06.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022]
Abstract
The all-atom molecular dynamics method can characterize the molecular-level interactions in DNA and DNA-protein systems with unprecedented resolution. Recent advances in computational technologies have allowed the method to reveal the unbiased behavior of such systems at the microseconds time scale, whereas enhanced sampling approaches have matured enough to characterize the interaction free energy with quantitative precision. Here, we describe recent progress toward increasing the realism of such simulations by refining the accuracy of the molecular dynamics force field, and we highlight recent application of the method to systems of outstanding biological interest.
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Affiliation(s)
- Jejoong Yoo
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea; Center for Self-assembly and Complexity, Institute for Basic Science, Pohang 37673, Republic of Korea.
| | - David Winogradoff
- Department of Physics and the Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Aleksei Aksimentiev
- Department of Physics and the Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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34
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Brinkman JA, Liu Y, Kron SJ. Small-molecule drug repurposing to target DNA damage repair and response pathways. Semin Cancer Biol 2020; 68:230-241. [PMID: 32113999 DOI: 10.1016/j.semcancer.2020.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 12/12/2022]
Abstract
For decades genotoxic therapy has been a mainstay in the treatment of cancer, based on the understanding that the deregulated growth and genomic instability that drive malignancy also confer a shared vulnerability. Although chemotherapy and radiation can be curative, only a fraction of patients benefit, while nearly all are subjected to the harmful side-effects. Drug repurposing, defined here as retooling existing drugs and compounds as chemo or radiosensitizers, offers an attractive route to identifying otherwise non-toxic agents that can potentiate the benefits of genotoxic cancer therapy to enhance the therapeutic ratio. This review seeks to highlight recent progress in defining cellular mechanisms of the DNA damage response including damage sensing, chromatin modification, DNA repair, checkpoint signaling, and downstream survival and death pathways, as a framework to determine which drugs and natural products may offer the most potential for repurposing as chemo- and/or radiosensitizers. We point to classical examples and recent progress that have identified drugs that disrupt cellular responses to DNA damage and may offer the greatest clinical potential. The most important next steps may be to initiate prospective clinical trials toward translating these laboratory discoveries to benefit patients.
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Affiliation(s)
- Jacqueline A Brinkman
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, United States; Ludwig Center for Metastasis Research, University of Chicago, Chicago, IL, United States
| | - Yue Liu
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, United States; Ludwig Center for Metastasis Research, University of Chicago, Chicago, IL, United States
| | - Stephen J Kron
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, United States; Ludwig Center for Metastasis Research, University of Chicago, Chicago, IL, United States.
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35
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Syeda AH, Wollman AJM, Hargreaves AL, Howard JAL, Brüning JG, McGlynn P, Leake MC. Single-molecule live cell imaging of Rep reveals the dynamic interplay between an accessory replicative helicase and the replisome. Nucleic Acids Res 2020; 47:6287-6298. [PMID: 31028385 PMCID: PMC6614839 DOI: 10.1093/nar/gkz298] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 04/01/2019] [Accepted: 04/24/2019] [Indexed: 12/21/2022] Open
Abstract
DNA replication must cope with nucleoprotein barriers that impair efficient replisome translocation. Biochemical and genetic studies indicate accessory helicases play essential roles in replication in the presence of nucleoprotein barriers, but how they operate inside the cell is unclear. With high-speed single-molecule microscopy we observed genomically-encoded fluorescent constructs of the accessory helicase Rep and core replisome protein DnaQ in live Escherichia coli cells. We demonstrate that Rep colocalizes with 70% of replication forks, with a hexameric stoichiometry, indicating maximal occupancy of the single DnaB hexamer. Rep associates dynamically with the replisome with an average dwell time of 6.5 ms dependent on ATP hydrolysis, indicating rapid binding then translocation away from the fork. We also imaged PriC replication restart factor and observe Rep-replisome association is also dependent on PriC. Our findings suggest two Rep-replisome populations in vivo: one continually associating with DnaB then translocating away to aid nucleoprotein barrier removal ahead of the fork, another assisting PriC-dependent reloading of DnaB if replisome progression fails. These findings reveal how a single helicase at the replisome provides two independent ways of underpinning replication of protein-bound DNA, a problem all organisms face as they replicate their genomes.
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Affiliation(s)
- Aisha H Syeda
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
| | - Adam J M Wollman
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
| | - Alex L Hargreaves
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
| | - Jamieson A L Howard
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
| | | | - Peter McGlynn
- Department of Biology, University of York, York YO10 5DD, UK
| | - Mark C Leake
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
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36
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Lu J, Wang C, Wang H, Zheng H, Bai W, Lei D, Tian Y, Xiao Y, You S, Wang Q, Yu X, Liu S, Liu X, Chen L, Jang L, Wang C, Zhao Z, Wan J. OsMFS1/ OsHOP2 Complex Participates in Rice Male and Female Development. FRONTIERS IN PLANT SCIENCE 2020; 11:518. [PMID: 32499797 PMCID: PMC7243175 DOI: 10.3389/fpls.2020.00518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/06/2020] [Indexed: 05/08/2023]
Abstract
Meiosis plays an essential role in the production of gametes and genetic diversity of posterities. The normal double-strand break (DSB) repair is vital to homologous recombination (HR) and occurrence of DNA fragment exchange, but the underlying molecular mechanism remain elusive. Here, we characterized a completely sterile Osmfs1 (male and female sterility 1) mutant which has its pollen and embryo sacs both aborted at the reproductive stage due to severe chromosome defection. Map-based cloning revealed that the OsMFS1 encodes a meiotic coiled-coil protein, and it is responsible for DSB repairing that acts as an important cofactor to stimulate the single strand invasion. Expression pattern analyses showed the OsMFS1 was preferentially expressed in meiosis stage. Subcellular localization analysis of OsMFS1 revealed its association with the nucleus exclusively. In addition, a yeast two-hybrid (Y2H) and pull-down assay showed that OsMFS1 could physically interact with OsHOP2 protein to form a stable complex to ensure faithful homologous recombination. Taken together, our results indicated that OsMFS1 is indispensable to the normal development of anther and embryo sacs in rice.
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Affiliation(s)
- Jiayu Lu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Chaolong Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Haiyu Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Hai Zheng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Wenting Bai
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Dekun Lei
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Yunlu Tian
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Yanjia Xiao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Shimin You
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Qiming Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Xiaowen Yu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Shijia Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Xi Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Liangming Chen
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Ling Jang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Chunming Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
| | - Zhigang Zhao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
- *Correspondence: Zhigang Zhao,
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, China
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
- Jianmin Wan, ;
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37
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Protein-protein complexes as targets for drug discovery against infectious diseases. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 121:237-251. [PMID: 32312423 DOI: 10.1016/bs.apcsb.2019.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Antibiotics are therapeutic agents against bacterial infections, however, the emergence of multiple and extremely drug-resistant microbes (Multi-Drug Resistant and Extremely Drug-Resistant) are compromising the effectiveness of the currently available treatment options. The drug resistance is not a novel crisis, the current pace of drug discovery has failed to compete with the growth of MDR and XDR pathogenic strains and therefore, it is highly central to find out novel antimicrobial drugs with unique mechanisms of action which may reduce the burden of MDR and XDR pathogenic strains. Protein-protein interactions (PPIs) are involved in a countless of the physiological and cellular phenomena and have become an attractive target to treat the diseases. Therefore, targeting PPIs in infectious agents may offer a completely novel strategy of intervention to develop anti-infective drugs that may combat the ever-increasing rate of drug resistant strains. This chapter describes how small molecule candidate inhibitors that are capable of disrupting the PPIs in pathogenic microbes and it could be an alternative lead discovery strategy to obtain novel antibiotics. Over the last three decades, there has been increasing efforts focused on the manipulation of PPIs in order to develop novel therapeutic interventions. The diversity and complexity of such a complex and highly dynamic systems pose many challenges in targeting PPIs by drug-like molecules with necessary selectivity and potency. Traditional and novel drug discovery strategies have provided tools for designing and assessing PPI inhibitors against infectious diseases.
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Cerrón F, de Lorenzo S, Lemishko KM, Ciesielski GL, Kaguni LS, Cao FJ, Ibarra B. Replicative DNA polymerases promote active displacement of SSB proteins during lagging strand synthesis. Nucleic Acids Res 2019; 47:5723-5734. [PMID: 30968132 PMCID: PMC6582349 DOI: 10.1093/nar/gkz249] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 03/22/2019] [Accepted: 03/29/2019] [Indexed: 11/23/2022] Open
Abstract
Genome replication induces the generation of large stretches of single-stranded DNA (ssDNA) intermediates that are rapidly protected by single-stranded DNA-binding (SSB) proteins. To date, the mechanism by which tightly bound SSBs are removed from ssDNA by the lagging strand DNA polymerase without compromising the advance of the replication fork remains unresolved. Here, we aimed to address this question by measuring, with optical tweezers, the real-time replication kinetics of the human mitochondrial and bacteriophage T7 DNA polymerases on free-ssDNA, in comparison with ssDNA covered with homologous and non-homologous SSBs under mechanical tension. We find important differences between the force dependencies of the instantaneous replication rates of each polymerase on different substrates. Modeling of the data supports a mechanism in which strong, specific polymerase-SSB interactions, up to ∼12 kBT, are required for the polymerase to dislodge SSB from the template without compromising its instantaneous replication rate, even under stress conditions that may affect SSB–DNA organization and/or polymerase–SSB communication. Upon interaction, the elimination of template secondary structure by SSB binding facilitates the maximum replication rate of the lagging strand polymerase. In contrast, in the absence of polymerase–SSB interactions, SSB poses an effective barrier for the advance of the polymerase, slowing down DNA synthesis.
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Affiliation(s)
- Fernando Cerrón
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Departamento Estructura de la Materia, Física Térmica y Electrónica. Universidad Complutense. 28040 Madrid, Spain
| | - Sara de Lorenzo
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain
| | - Kateryna M Lemishko
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit "Unidad de Nanobiotecnología". 28049 Madrid, Spain
| | - Grzegorz L Ciesielski
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Laurie S Kaguni
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Francisco J Cao
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Departamento Estructura de la Materia, Física Térmica y Electrónica. Universidad Complutense. 28040 Madrid, Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit "Unidad de Nanobiotecnología". 28049 Madrid, Spain
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Jiang X, Zhang L, An J, Wang M, Teng M, Guo Q, Li X. Caulobacter crescentus β sliding clamp employs a noncanonical regulatory model of DNA replication. FEBS J 2019; 287:2292-2311. [PMID: 31725950 DOI: 10.1111/febs.15138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 08/23/2019] [Accepted: 11/12/2019] [Indexed: 01/19/2023]
Abstract
The eubacterial β sliding clamp (DnaN) plays a crucial role in DNA metabolism through direct interactions with DNA, polymerases, and a variety of protein factors. A canonical protein-DnaN interaction has been identified in Escherichia coli and some other species, during which protein partners are tethered into the conserved canonical hydrophobic crevice of DnaN via the consensus β-binding motif. Caulobacter crescentus is an excellent research model for use in the investigation of DNA replication and cell-cycle regulation due to its unique asymmetric cell division pattern with restricted replication initiation; however, little is known about the specific features of C. crescentus DnaN (CcDnaN). Here, we report a significant divergence in the association of CcDnaN with proteins based on docking analysis and crystal structures that show that the β-binding motifs of its protein partners bind a novel pocket instead of the canonical site. Pull-down and isothermal titration calorimetry results revealed that mutations within the novel pocket disrupt protein-CcDnaN interactions. It was also shown by replication and regulatory inactivation of DnaA assays that mediation of protein interaction by the novel pocket is closely related to the performance of CcDnaN during replication and the DnaN-mediated regulation process. Moreover, assessments of clamp competition showed that DNA does not compete with protein partners when binding to the novel pocket. Overall, our structural and biochemical analyses provide strong evidence that CcDnaN employs a noncanonical protein association pattern.
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Affiliation(s)
- Xuguang Jiang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.,Key Laboratory of Structural Biology, Chinese Academy of Sciences, Hefei, China
| | - Linjuan Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.,Key Laboratory of Structural Biology, Chinese Academy of Sciences, Hefei, China
| | - Jiancheng An
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China
| | - Mingxing Wang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.,Key Laboratory of Structural Biology, Chinese Academy of Sciences, Hefei, China
| | - Maikun Teng
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.,Key Laboratory of Structural Biology, Chinese Academy of Sciences, Hefei, China
| | - Qiong Guo
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.,Key Laboratory of Structural Biology, Chinese Academy of Sciences, Hefei, China
| | - Xu Li
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.,Key Laboratory of Structural Biology, Chinese Academy of Sciences, Hefei, China
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Bogutzki A, Naue N, Litz L, Pich A, Curth U. E. coli primase and DNA polymerase III holoenzyme are able to bind concurrently to a primed template during DNA replication. Sci Rep 2019; 9:14460. [PMID: 31595021 PMCID: PMC6783573 DOI: 10.1038/s41598-019-51031-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 09/24/2019] [Indexed: 11/15/2022] Open
Abstract
During DNA replication in E. coli, a switch between DnaG primase and DNA polymerase III holoenzyme (pol III) activities has to occur every time when the synthesis of a new Okazaki fragment starts. As both primase and the χ subunit of pol III interact with the highly conserved C-terminus of single-stranded DNA-binding protein (SSB), it had been proposed that the binding of both proteins to SSB is mutually exclusive. Using a replication system containing the origin of replication of the single-stranded DNA phage G4 (G4ori) saturated with SSB, we tested whether DnaG and pol III can bind concurrently to the primed template. We found that the addition of pol III does not lead to a displacement of primase, but to the formation of higher complexes. Even pol III-mediated primer elongation by one or several DNA nucleotides does not result in the dissociation of DnaG. About 10 nucleotides have to be added in order to displace one of the two primase molecules bound to SSB-saturated G4ori. The concurrent binding of primase and pol III is highly plausible, since even the SSB tetramer situated directly next to the 3′-terminus of the primer provides four C-termini for protein-protein interactions.
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Affiliation(s)
- Andrea Bogutzki
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, 30625, Carl-Neuberg-Str. 1, Germany
| | - Natalie Naue
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, 30625, Carl-Neuberg-Str. 1, Germany.,Inamed GmbH, Gauting, 82131, Germany
| | - Lidia Litz
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, 30625, Carl-Neuberg-Str. 1, Germany
| | - Andreas Pich
- Institute for Toxicology, Hannover Medical School, Hannover, 30625, Carl-Neuberg-Str. 1, Germany
| | - Ute Curth
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, 30625, Carl-Neuberg-Str. 1, Germany.
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Abstract
Maintenance of genome integrity is a key process in all organisms. DNA polymerases (Pols) are central players in this process as they are in charge of the faithful reproduction of the genetic information, as well as of DNA repair. Interestingly, all eukaryotes possess a large repertoire of polymerases. Three protein complexes, DNA Pol α, δ, and ε, are in charge of nuclear DNA replication. These enzymes have the fidelity and processivity required to replicate long DNA sequences, but DNA lesions can block their progression. Consequently, eukaryotic genomes also encode a variable number of specialized polymerases (between five and 16 depending on the organism) that are involved in the replication of damaged DNA, DNA repair, and organellar DNA replication. This diversity of enzymes likely stems from their ability to bypass specific types of lesions. In the past 10–15 years, our knowledge regarding plant DNA polymerases dramatically increased. In this review, we discuss these recent findings and compare acquired knowledge in plants to data obtained in other eukaryotes. We also discuss the emerging links between genome and epigenome replication.
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Lushnikov A, Hooy R, Sohn J, Krasnoslobodtsev A. Characterization of DNA bound cyclic GMP-AMP synthase using atomic force microscopy imaging. Methods Enzymol 2019; 625:157-166. [PMID: 31455525 DOI: 10.1016/bs.mie.2019.07.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The protocol described herein allows for acquiring topography images of DNA-protein complexes using Atomic Force Microscopy imaging. Since the very beginning of this method, AFM has been an indispensable tool for characterization of biomolecular complexes with exceptional capability of observing single complexes. This method can visualize structural characteristics of DNA-protein assemblies and evaluate differences between individual complexes. Although this protocol is generally applicable to a large number of various proteins complexed with DNA, we use cyclic G/AMP synthase (cGAS) enzyme as a case study for the protocol description.
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Affiliation(s)
- Alexander Lushnikov
- Nanoimaging Core Facility at the University of Nebraska Medical Center, Omaha, NE, United States
| | - Richard Hooy
- Department of Biophysics and Biophysical Chemistry, John Hopkins School of Medicine, Baltimore, MD, United States
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, John Hopkins School of Medicine, Baltimore, MD, United States
| | - Alexey Krasnoslobodtsev
- Nanoimaging Core Facility at the University of Nebraska Medical Center, Omaha, NE, United States; Department of Physics, University of Nebraska Omaha, Omaha, NE, United States.
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Liu TY, Liu JJ, Aditham AJ, Nogales E, Doudna JA. Target preference of Type III-A CRISPR-Cas complexes at the transcription bubble. Nat Commun 2019; 10:3001. [PMID: 31278272 PMCID: PMC6611850 DOI: 10.1038/s41467-019-10780-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/28/2019] [Indexed: 12/26/2022] Open
Abstract
Type III-A CRISPR-Cas systems are prokaryotic RNA-guided adaptive immune systems that use a protein-RNA complex, Csm, for transcription-dependent immunity against foreign DNA. Csm can cleave RNA and single-stranded DNA (ssDNA), but whether it targets one or both nucleic acids during transcription elongation is unknown. Here, we show that binding of a Thermus thermophilus (T. thermophilus) Csm (TthCsm) to a nascent transcript in a transcription elongation complex (TEC) promotes tethering but not direct contact of TthCsm with RNA polymerase (RNAP). Biochemical experiments show that both TthCsm and Staphylococcus epidermidis (S. epidermidis) Csm (SepCsm) cleave RNA transcripts, but not ssDNA, at the transcription bubble. Taken together, these results suggest that Type III systems primarily target transcripts, instead of unwound ssDNA in TECs, for immunity against double-stranded DNA (dsDNA) phages and plasmids. This reveals similarities between Csm and eukaryotic RNA interference, which also uses RNA-guided RNA targeting to silence actively transcribed genes.
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MESH Headings
- Adaptive Immunity/genetics
- Bacteriophages/immunology
- CRISPR-Cas Systems/genetics
- CRISPR-Cas Systems/immunology
- Clustered Regularly Interspaced Short Palindromic Repeats/genetics
- Clustered Regularly Interspaced Short Palindromic Repeats/immunology
- DNA, Single-Stranded/genetics
- DNA, Single-Stranded/immunology
- DNA, Single-Stranded/metabolism
- DNA-Directed RNA Polymerases/metabolism
- Plasmids/immunology
- RNA, Guide, CRISPR-Cas Systems/genetics
- RNA, Guide, CRISPR-Cas Systems/immunology
- RNA, Guide, CRISPR-Cas Systems/metabolism
- Staphylococcus epidermidis/genetics
- Staphylococcus epidermidis/immunology
- Thermus thermophilus/genetics
- Thermus thermophilus/immunology
- Transcription Elongation, Genetic/immunology
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Affiliation(s)
- Tina Y Liu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences, Berkeley, CA, 94720, USA
| | - Jun-Jie Liu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences, Berkeley, CA, 94720, USA
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Abhishek J Aditham
- Department of Chemical & Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
| | - Eva Nogales
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences, Berkeley, CA, 94720, USA
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA.
- California Institute for Quantitative Biosciences, Berkeley, CA, 94720, USA.
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA.
- Gladstone Institutes, San Francisco, CA, 94158, USA.
- Innovative Genomics Institute, University of California, Berkeley, CA, 94720, USA.
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
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Parisi MG, Maisano M, Cappello T, Oliva S, Mauceri A, Toubiana M, Cammarata M. Responses of marine mussel Mytilus galloprovincialis (Bivalvia: Mytilidae) after infection with the pathogen Vibrio splendidus. Comp Biochem Physiol C Toxicol Pharmacol 2019; 221:1-9. [PMID: 30905845 DOI: 10.1016/j.cbpc.2019.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 12/12/2022]
Abstract
Bivalve molluscs possess effective cellular and humoral defence mechanisms against bacterial infection. Although the immune responses of mussels to challenge with pathogenic vibrios have been largely investigated, the effects at the site of injection at the tissue level have not been so far evaluated. To this aim, mussels Mytilus galloprovincialis were herein in vivo challenged with Vibrio splendidus to assess the responses induced in hemolymph and posterior adductor muscle (PAM), being the site of bacterial infection. The number of living intra-hemocyte bacteria increased after the first hour post-injection (p.i.), suggesting the occurrence of an intense phagocytosis, while clearance was observed within 24 h p.i. A recruitment of hemocytes at the injection site was found in mussel PAM, together with marked morphological changes in the volume of muscular fibers, with a recovery of muscle tissue organization after 48 h p.i. A concomitant impairment in the osmoregulatory processes were observed in PAM by an initial inhibition of aquaporins and increased immunopositivity of Na+/K+ ATPase ionic pump, strictly related to the histological alterations and hemocyte infiltration detected in PAM. Accordingly, an intense cell turnover activity was also recorded following the infection event. Overall, results indicated the hemolymph as the system responsible for the physiological adaptations in mussels to stressful factors, such as pathogenicity, for the maintenance of homeostasis and immune defence. Also, the osmotic balance and cell turnover can be used as objective diagnostic criteria to evaluate the physiological state of mussels following bacterial infection, which may be relevant in aquaculture and biomonitoring studies.
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Affiliation(s)
- Maria Giovanna Parisi
- Marine Immunobiology Laboratory, Dipartimento di Scienze della Terra e del Mare, University of Palermo, Palermo, Italy
| | - Maria Maisano
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy.
| | - Tiziana Cappello
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Sabrina Oliva
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Angela Mauceri
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Mylene Toubiana
- HSM, University of Montpellier, IRD, CNRS, Montpellier, France
| | - Matteo Cammarata
- Marine Immunobiology Laboratory, Dipartimento di Scienze della Terra e del Mare, University of Palermo, Palermo, Italy.
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In vivo demonstration of enhanced binding between β-clamp and DnaE of pol III bearing consensus i-CBM. Genes Genomics 2019; 41:613-619. [PMID: 30929144 DOI: 10.1007/s13258-019-00796-9] [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: 10/04/2018] [Accepted: 02/15/2019] [Indexed: 10/27/2022]
Abstract
BACKGROUND Among several key protein-protein and protein-DNA interactions within the replisome, the interaction between β-clamp and the DNA polymerase (Pol) III is of crucial importance. This interaction is mediated by a five or six-residue conserved sequence of the DnaE subunit of Pol III, referred to as the Clamp Binding Motif (CBM). In E. coli, DnaE contains two CBMs designated as e-CBM and i-CBM. A consensus sequence (QL[S/D]LF) for the CBMs has previously been proposed and studies involving mutagenesis of both the CBMs have evaluated their protein-binding properties. Surface Plasmon Resonance has been used to show that replacing i-CBM in DnaE with the consensus sequence enhances its binding to β-clamp 120-fold. OBJECTIVE The current study was aimed to evaluate in vivo interaction between DnaE bearing the consensus i-CBM and β-clamp. METHOD The C-terminal 405 residues of DnaE, bearing either the consensus i-CBM or the WT i-CBM, with β-clamp were co-expressed in E. coli followed by co-purification of the protein complexes. The interaction was assessed by the ability of the co-expressed proteins to form stable complexes during both affinity and gel filtration chromatography. RESULT The interaction of β-clamp with DnaEΔ755M containing the consensus i-CBM was found to be more stable than with WT DnaEΔ755, consistent with the in vitro data previously reported. CONCLUSION The presence of the pieces of sheared DNA generated during sonication promote the interaction of DnaEΔ755M with β-clamp by binding the OB-fold of DnaEΔ755M and β-clamp and serves as a bridge between them.
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Romero H, Torres R, Hernández-Tamayo R, Carrasco B, Ayora S, Graumann PL, Alonso JC. Bacillus subtilis RarA acts at the interplay between replication and repair-by-recombination. DNA Repair (Amst) 2019; 78:27-36. [PMID: 30954900 DOI: 10.1016/j.dnarep.2019.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 02/20/2019] [Accepted: 03/20/2019] [Indexed: 10/27/2022]
Abstract
Bacterial RarA is thought to play crucial roles in the cellular response to blocked replication forks. We show that lack of Bacillus subtilis RarA renders cells very sensitive to H2O2, but not to methyl methane sulfonate or 4-nitroquinoline-1-oxide. RarA is epistatic to RecA in response to DNA damage. Inactivation of rarA partially suppressed the DNA repair defect of mutants lacking translesion synthesis polymerases. RarA may contribute to error-prone DNA repair as judged by the reduced frequency of rifampicin-resistant mutants in ΔrarA and in ΔpolY1 ΔrarA cells. The absence of RarA strongly reduced the viability of dnaD23ts and dnaB37ts cells upon partial thermal inactivation, suggesting that ΔrarA cells are deficient in replication fork assembly. A ΔrarA mutation also partially reduced the viability of dnaC30ts and dnaX51ts cells and slightly improved the viability of dnaG40ts cells at semi-permissive temperature. These results suggest that RarA links re-initiation of DNA replication with repair-by-recombination by controlling the access of the replication machinery to a collapsed replication fork.
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Affiliation(s)
- Hector Romero
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin St., 28049, Madrid, Spain; SYNMIKRO, LOEWE-Zentrum für Synthetische Mikrobiologie, Hans-Meerwein-Straße, 35043, Marburg, Germany; Fachbereich Chemie, Hans-Meerwein-Straße 4, 35032, Marburg, Germany
| | - Rubén Torres
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin St., 28049, Madrid, Spain
| | - Rogelio Hernández-Tamayo
- SYNMIKRO, LOEWE-Zentrum für Synthetische Mikrobiologie, Hans-Meerwein-Straße, 35043, Marburg, Germany; Fachbereich Chemie, Hans-Meerwein-Straße 4, 35032, Marburg, Germany
| | - Begoña Carrasco
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin St., 28049, Madrid, Spain
| | - Silvia Ayora
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin St., 28049, Madrid, Spain
| | - Peter L Graumann
- SYNMIKRO, LOEWE-Zentrum für Synthetische Mikrobiologie, Hans-Meerwein-Straße, 35043, Marburg, Germany; Fachbereich Chemie, Hans-Meerwein-Straße 4, 35032, Marburg, Germany.
| | - Juan C Alonso
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin St., 28049, Madrid, Spain.
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Li Y, Chen Z, Matthews LA, Simmons LA, Biteen JS. Dynamic Exchange of Two Essential DNA Polymerases during Replication and after Fork Arrest. Biophys J 2019; 116:684-693. [PMID: 30686488 DOI: 10.1016/j.bpj.2019.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/23/2018] [Accepted: 01/04/2019] [Indexed: 01/01/2023] Open
Abstract
The replisome is a multiprotein machine responsible for the faithful replication of chromosomal and plasmid DNA. Using single-molecule super-resolution imaging, we characterized the dynamics of three replisomal proteins in live Bacillus subtilis cells: the two replicative DNA polymerases, PolC and DnaE, and a processivity clamp loader subunit, DnaX. We quantified the protein mobility and dwell times during normal replication and following replication fork stress using damage-independent and damage-dependent conditions. With these results, we report the dynamic and cooperative process of DNA replication based on changes in the measured diffusion coefficients and dwell times. These experiments show that the replication proteins are all highly dynamic and that the exchange rate depends on whether DNA synthesis is active or arrested. Our results also suggest coupling between PolC and DnaX in the DNA replication process and indicate that DnaX provides an important role in synthesis during repair. Furthermore, our results suggest that DnaE provides a limited contribution to chromosomal replication and repair in vivo.
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Affiliation(s)
- Yilai Li
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan
| | - Ziyuan Chen
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan
| | - Lindsay A Matthews
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan
| | - Lyle A Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan.
| | - Julie S Biteen
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan; Department of Chemistry, University of Michigan, Ann Arbor, Michigan.
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48
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A tough row to hoe: when replication forks encounter DNA damage. Biochem Soc Trans 2018; 46:1643-1651. [PMID: 30514768 DOI: 10.1042/bst20180308] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 11/05/2018] [Accepted: 11/07/2018] [Indexed: 01/12/2023]
Abstract
Eukaryotic cells continuously experience DNA damage that can perturb key molecular processes like DNA replication. DNA replication forks that encounter DNA lesions typically slow and may stall, which can lead to highly detrimental fork collapse if appropriate protective measures are not executed. Stabilization and protection of stalled replication forks ensures the possibility of effective fork restart and prevents genomic instability. Recent efforts from multiple laboratories have highlighted several proteins involved in replication fork remodeling and DNA damage response pathways as key regulators of fork stability. Homologous recombination factors such as RAD51, BRCA1, and BRCA2, along with components of the Fanconi Anemia pathway, are now known to be crucial for stabilizing stalled replication forks and preventing nascent strand degradation. Several checkpoint proteins have additionally been implicated in fork protection. Ongoing work in this area continues to shed light on a sophisticated molecular pathway that balances the action of DNA resection and fork protection to maintain genomic integrity, with important implications for the fate of both normal and malignant cells following replication stress.
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Carro L. Protein-protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics. Beilstein J Org Chem 2018; 14:2881-2896. [PMID: 30546472 PMCID: PMC6278769 DOI: 10.3762/bjoc.14.267] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/02/2018] [Indexed: 12/11/2022] Open
Abstract
Antibiotics are potent pharmacological weapons against bacterial infections; however, the growing antibiotic resistance of microorganisms is compromising the efficacy of the currently available pharmacotherapies. Even though antimicrobial resistance is not a new problem, antibiotic development has failed to match the growth of resistant pathogens and hence, it is highly critical to discover new anti-infective drugs with novel mechanisms of action which will help reducing the burden of multidrug-resistant microorganisms. Protein-protein interactions (PPIs) are involved in a myriad of vital cellular processes and have become an attractive target to treat diseases. Therefore, targeting PPI networks in bacteria may offer a new and unconventional point of intervention to develop novel anti-infective drugs which can combat the ever-increasing rate of multidrug-resistant bacteria. This review describes the progress achieved towards the discovery of molecules that disrupt PPI systems in bacteria for which inhibitors have been identified and whose targets could represent an alternative lead discovery strategy to obtain new anti-infective molecules.
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Affiliation(s)
- Laura Carro
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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Ligasová A, Koberna K. DNA Replication: From Radioisotopes to Click Chemistry. Molecules 2018; 23:molecules23113007. [PMID: 30453631 PMCID: PMC6278288 DOI: 10.3390/molecules23113007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 12/14/2022] Open
Abstract
The replication of nuclear and mitochondrial DNA are basic processes assuring the doubling of the genetic information of eukaryotic cells. In research of the basic principles of DNA replication, and also in the studies focused on the cell cycle, an important role is played by artificially-prepared nucleoside and nucleotide analogues that serve as markers of newly synthesized DNA. These analogues are incorporated into the DNA during DNA replication, and are subsequently visualized. Several methods are used for their detection, including the highly popular click chemistry. This review aims to provide the readers with basic information about the various possibilities of the detection of replication activity using nucleoside and nucleotide analogues, and to show the strengths and weaknesses of those different detection systems, including click chemistry for microscopic studies.
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Affiliation(s)
- Anna Ligasová
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Hněvotínská 5, 779 00 Olomouc, Czech Republic.
| | - Karel Koberna
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Hněvotínská 5, 779 00 Olomouc, Czech Republic.
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