1
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Martin-Gonzalez A, Tišma M, Analikwu B, Barth A, Janissen R, Antar H, Kemps G, Gruber S, Dekker C. DNA supercoiling enhances DNA condensation by ParB proteins. Nucleic Acids Res 2024; 52:13255-13268. [PMID: 39441069 PMCID: PMC11602141 DOI: 10.1093/nar/gkae936] [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: 07/17/2024] [Revised: 09/27/2024] [Accepted: 10/08/2024] [Indexed: 10/25/2024] Open
Abstract
The ParABS system plays a critical role in bacterial chromosome segregation. The key component of this system, ParB, loads and spreads along DNA to form a local protein-DNA condensate known as a partition complex. As bacterial chromosomes are heavily supercoiled due to the continuous action of RNA polymerases, topoisomerases and nucleoid-associated proteins, it is important to study the impact of DNA supercoiling on the ParB-DNA partition complex formation. Here, we use an in-vitro single-molecule assay to visualize ParB on supercoiled DNA. Unlike most DNA-binding proteins, individual ParB proteins are found to not pin plectonemes on supercoiled DNA, but freely diffuse along supercoiled DNA. We find that DNA supercoiling enhances ParB-DNA condensation, which initiates at lower ParB concentrations than on DNA that is torsionally relaxed. ParB proteins induce a DNA-protein condensate that strikingly absorbs all supercoiling writhe. Our findings provide mechanistic insights that have important implications for our understanding of bacterial chromosome organization and segregation.
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Affiliation(s)
- Alejandro Martin-Gonzalez
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Miloš Tišma
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Brian T Analikwu
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Anders Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
- BITZ Transformation Lab, Deggendorf Institute of Technology, 94363 Oberschneiding, Germany
| | - Hammam Antar
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL); CH-1015 Lausanne, Switzerland
| | - Gianluca Kemps
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL); CH-1015 Lausanne, Switzerland
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
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2
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Zhao Y, Guo L, Hu J, Ren Z, Li Y, Hu M, Zhang X, Bi L, Li D, Ma H, Liu C, Sun B. Phase-separated ParB enforces diverse DNA compaction modes and stabilizes the parS-centered partition complex. Nucleic Acids Res 2024; 52:8385-8398. [PMID: 38908027 PMCID: PMC11317135 DOI: 10.1093/nar/gkae533] [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: 02/28/2024] [Revised: 05/20/2024] [Accepted: 06/13/2024] [Indexed: 06/24/2024] Open
Abstract
The tripartite ParABS system mediates chromosome segregation in the majority of bacterial species. Typically, DNA-bound ParB proteins around the parS sites condense the chromosomal DNA into a higher-order multimeric nucleoprotein complex for the ParA-driven partition. Despite extensive studies, the molecular mechanism underlying the dynamic assembly of the partition complex remains unclear. Herein, we demonstrate that Bacillus subtilis ParB (Spo0J), through the multimerization of its N-terminal domain, forms phase-separated condensates along a single DNA molecule, leading to the concurrent organization of DNA into a compact structure. Specifically, in addition to the co-condensation of ParB dimers with DNA, the engagement of well-established ParB condensates with DNA allows for the compression of adjacent DNA and the looping of distant DNA. Notably, the presence of CTP promotes the formation of condensates by a low amount of ParB at parS sites, triggering two-step DNA condensation. Remarkably, parS-centered ParB-DNA co-condensate constitutes a robust nucleoprotein architecture capable of withstanding disruptive forces of tens of piconewton. Overall, our findings unveil diverse modes of DNA compaction enabled by phase-separated ParB and offer new insights into the dynamic assembly and maintenance of the bacterial partition complex.
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Affiliation(s)
- Yilin Zhao
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Lijuan Guo
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jiaojiao Hu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhiyun Ren
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanan Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Meng Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xia Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Lulu Bi
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hanhui Ma
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Bo Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
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3
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Tišma M, Kaljević J, Gruber S, Le TBK, Dekker C. Connecting the dots: key insights on ParB for chromosome segregation from single-molecule studies. FEMS Microbiol Rev 2024; 48:fuad067. [PMID: 38142222 PMCID: PMC10786196 DOI: 10.1093/femsre/fuad067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 12/25/2023] Open
Abstract
Bacterial cells require DNA segregation machinery to properly distribute a genome to both daughter cells upon division. The most common system involved in chromosome and plasmid segregation in bacteria is the ParABS system. A core protein of this system - partition protein B (ParB) - regulates chromosome organization and chromosome segregation during the bacterial cell cycle. Over the past decades, research has greatly advanced our knowledge of the ParABS system. However, many intricate details of the mechanism of ParB proteins were only recently uncovered using in vitro single-molecule techniques. These approaches allowed the exploration of ParB proteins in precisely controlled environments, free from the complexities of the cellular milieu. This review covers the early developments of this field but emphasizes recent advances in our knowledge of the mechanistic understanding of ParB proteins as revealed by in vitro single-molecule methods. Furthermore, we provide an outlook on future endeavors in investigating ParB, ParB-like proteins, and their interaction partners.
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Affiliation(s)
- Miloš Tišma
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology; Van der Maasweg 9, Delft, the Netherlands
| | - Jovana Kaljević
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney Lane, NR4 7UH Norwich, United Kingdom
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, UNIL-Sorge, Biophore, CH-1015 Lausanne, Switzerland
| | - Tung B K Le
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney Lane, NR4 7UH Norwich, United Kingdom
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology; Van der Maasweg 9, Delft, the Netherlands
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4
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Tišma M, Janissen R, Antar H, Martin-Gonzalez A, Barth R, Beekman T, van der Torre J, Michieletto D, Gruber S, Dekker C. Dynamic ParB-DNA interactions initiate and maintain a partition condensate for bacterial chromosome segregation. Nucleic Acids Res 2023; 51:11856-11875. [PMID: 37850647 PMCID: PMC10681803 DOI: 10.1093/nar/gkad868] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/05/2023] [Accepted: 09/26/2023] [Indexed: 10/19/2023] Open
Abstract
In most bacteria, chromosome segregation is driven by the ParABS system where the CTPase protein ParB loads at the parS site to trigger the formation of a large partition complex. Here, we present in vitro studies of the partition complex for Bacillus subtilis ParB, using single-molecule fluorescence microscopy and AFM imaging to show that transient ParB-ParB bridges are essential for forming DNA condensates. Molecular Dynamics simulations confirm that condensation occurs abruptly at a critical concentration of ParB and show that multimerization is a prerequisite for forming the partition complex. Magnetic tweezer force spectroscopy on mutant ParB proteins demonstrates that CTP hydrolysis at the N-terminal domain is essential for DNA condensation. Finally, we show that transcribing RNA polymerases can steadily traverse the ParB-DNA partition complex. These findings uncover how ParB forms a stable yet dynamic partition complex for chromosome segregation that induces DNA condensation and segregation while enabling replication and transcription.
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Affiliation(s)
- Miloš Tišma
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Hammam Antar
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Alejandro Martin-Gonzalez
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Twan Beekman
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Davide Michieletto
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Stephan Gruber
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
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5
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Antar H, Gruber S. VirB, a transcriptional activator of virulence in Shigella flexneri, uses CTP as a cofactor. Commun Biol 2023; 6:1204. [PMID: 38007587 PMCID: PMC10676424 DOI: 10.1038/s42003-023-05590-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 11/15/2023] [Indexed: 11/27/2023] Open
Abstract
VirB is a transcriptional activator of virulence in the gram-negative bacterium Shigella flexneri encoded by the large invasion plasmid, pINV. It counteracts the transcriptional silencing by the nucleoid structuring protein, H-NS. Mutations in virB lead to loss of virulence. Studies suggested that VirB binds to specific DNA sequences, remodels the H-NS nucleoprotein complexes, and changes DNA supercoiling. VirB belongs to the superfamily of ParB proteins which are involved in plasmid and chromosome partitioning often as part of a ParABS system. Like ParB, VirB forms discrete foci in Shigella flexneri cells harbouring pINV. Our results reveal that purified preparations of VirB specifically bind the ribonucleotide CTP and slowly but detectably hydrolyse it with mild stimulation by the virS targeting sequences found on pINV. We show that formation of VirB foci in cells requires a virS site and CTP binding residues in VirB. Curiously, DNA stimulation of clamp closure appears efficient even without a virS sequence in vitro. Specificity for entrapment of virS DNA is however evident at elevated salt concentrations. These findings suggest that VirB acts as a CTP-dependent DNA clamp and indicate that the cellular microenvironment contributes to the accumulation of VirB specifically at virS sites.
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Affiliation(s)
- Hammam Antar
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, 1015, Lausanne, Switzerland
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, 1015, Lausanne, Switzerland.
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6
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Kawalek A, Bartosik AA, Jagura-Burdzy G. Robust ParB Binding to Half- parS Sites in Pseudomonas aeruginosa-A Mechanism for Retaining ParB on the Nucleoid? Int J Mol Sci 2023; 24:12517. [PMID: 37569892 PMCID: PMC10419367 DOI: 10.3390/ijms241512517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 07/28/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Chromosome segregation in Pseudomonas aeruginosa is assisted by the tripartite ParAB-parS system, composed of an ATPase (ParA), a DNA-binding protein (ParB) and its target parS sequence(s). ParB forms a nucleoprotein complex around four parSs (parS1-parS4) that overlaps oriC and facilitates relocation of newly synthesized ori domains inside the cells by ParA. Remarkably, ParB of P. aeruginosa also binds to numerous heptanucleotides (half-parSs) scattered in the genome. Here, using chromatin immunoprecipitation-sequencing (ChIP-seq), we analyzed patterns of ParB genome occupancy in cells growing under conditions of coupling or uncoupling between replication and cell division processes. Interestingly, a dissipation of ParB-parS complexes and a shift of ParB to half-parSs were observed during the transition from the exponential to stationary phase of growth on rich medium, suggesting the role of half-parSs in retaining ParB on the nucleoid within non-dividing P. aeruginosa cells. The ChIP-seq analysis of strains expressing ParB variants unable to dislocate from parSs showed that the ParB spreading ability is not required for ParB binding to half-parSs. Finally, a P. aeruginosa strain with mutated 25 half-parSs of the highest affinity towards ParB was constructed and analyzed. It showed altered ParB coverage of the oriC region and moderate changes in gene expression. Overall, this study characterizes a novel aspect of conserved bacterial chromosome segregation machinery.
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Affiliation(s)
- Adam Kawalek
- Laboratory of DNA Segregation and Life Cycle of Proteobacteria, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | | | - Grazyna Jagura-Burdzy
- Laboratory of DNA Segregation and Life Cycle of Proteobacteria, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
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7
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Connolley L, Schnabel L, Thanbichler M, Murray SM. Partition complex structure can arise from sliding and bridging of ParB dimers. Nat Commun 2023; 14:4567. [PMID: 37516778 PMCID: PMC10387095 DOI: 10.1038/s41467-023-40320-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 07/20/2023] [Indexed: 07/31/2023] Open
Abstract
In many bacteria, chromosome segregation requires the association of ParB to the parS-containing centromeric region to form the partition complex. However, the structure and formation of this complex have been unclear. Recently, studies have revealed that CTP binding enables ParB dimers to slide along DNA and condense the centromeric region through the formation of DNA bridges. Using semi-flexible polymer simulations, we demonstrate that these properties can explain partition complex formation. Transient ParB bridges organize DNA into globular states or hairpins and helical structures, depending on bridge lifetime, while separate simulations show that ParB sliding reproduces the multi-peaked binding profile observed in Caulobacter crescentus. Combining sliding and bridging into a unified model, we find that short-lived ParB bridges do not impede sliding and can reproduce both the binding profile and condensation of the nucleoprotein complex. Overall, our model elucidates the mechanism of partition complex formation and predicts its fine structure.
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Affiliation(s)
- Lara Connolley
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology, 35043, Marburg, Germany
| | - Lucas Schnabel
- Department of Biology, University of Marburg, 35043, Marburg, Germany
| | - Martin Thanbichler
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology, 35043, Marburg, Germany
- Department of Biology, University of Marburg, 35043, Marburg, Germany
| | - Seán M Murray
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology, 35043, Marburg, Germany.
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8
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Coloma J, Gonzalez-Rodriguez N, Balaguer FA, Gmurczyk K, Aicart-Ramos C, Nuero ÓM, Luque-Ortega JR, Calugaru K, Lue NF, Moreno-Herrero F, Llorca O. Molecular architecture and oligomerization of Candida glabrata Cdc13 underpin its telomeric DNA-binding and unfolding activity. Nucleic Acids Res 2023; 51:668-686. [PMID: 36629261 PMCID: PMC9881146 DOI: 10.1093/nar/gkac1261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 01/12/2023] Open
Abstract
The CST complex is a key player in telomere replication and stability, which in yeast comprises Cdc13, Stn1 and Ten1. While Stn1 and Ten1 are very well conserved across species, Cdc13 does not resemble its mammalian counterpart CTC1 either in sequence or domain organization, and Cdc13 but not CTC1 displays functions independently of the rest of CST. Whereas the structures of human CTC1 and CST have been determined, the molecular organization of Cdc13 remains poorly understood. Here, we dissect the molecular architecture of Candida glabrata Cdc13 and show how it regulates binding to telomeric sequences. Cdc13 forms dimers through the interaction between OB-fold 2 (OB2) domains. Dimerization stimulates binding of OB3 to telomeric sequences, resulting in the unfolding of ssDNA secondary structure. Once bound to DNA, Cdc13 prevents the refolding of ssDNA by mechanisms involving all domains. OB1 also oligomerizes, inducing higher-order complexes of Cdc13 in vitro. OB1 truncation disrupts these complexes, affects ssDNA unfolding and reduces telomere length in C. glabrata. Together, our results reveal the molecular organization of C. glabrata Cdc13 and how this regulates the binding and the structure of DNA, and suggest that yeast species evolved distinct architectures of Cdc13 that share some common principles.
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Affiliation(s)
- Javier Coloma
- Correspondence may also be addressed to Javier Coloma. Tel: +34 91 732 8000 (Ext 3033);
| | | | - Francisco A Balaguer
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Karolina Gmurczyk
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Clara Aicart-Ramos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Óscar M Nuero
- Molecular Interactions Facility, Centro de Investigaciones Biológicas Margarita Salas (CSIC), Madrid, Spain
| | - Juan Román Luque-Ortega
- Molecular Interactions Facility, Centro de Investigaciones Biológicas Margarita Salas (CSIC), Madrid, Spain
| | - Kimberly Calugaru
- Department of Microbiology and Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Neal F Lue
- Department of Microbiology and Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | | | - Oscar Llorca
- To whom correspondence should be addressed. Tel: +34 91 732 8000 (Ext 3000);
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9
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Picker MA, Karney MMA, Gerson TM, Karabachev AD, Duhart JC, McKenna JA, Wing HJ. Localized modulation of DNA supercoiling, triggered by the Shigella anti-silencer VirB, is sufficient to relieve H-NS-mediated silencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.09.523335. [PMID: 36711906 PMCID: PMC9882051 DOI: 10.1101/2023.01.09.523335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In Bacteria, nucleoid structuring proteins govern nucleoid dynamics and regulate transcription. In Shigella spp ., at ≤ 30 °C, the histone-like nucleoid structuring protein (H-NS) transcriptionally silences many genes on the large virulence plasmid. Upon a switch to 37 °C, VirB, a DNA binding protein and key transcriptional regulator of Shigella virulence, is produced. VirB functions to counter H-NS-mediated silencing in a process called transcriptional anti-silencing. Here, we show that VirB mediates a loss of negative DNA supercoils from our plasmid-borne, VirB-regulated PicsP-lacZ reporter, in vivo . The changes are not caused by a VirB-dependent increase in transcription, nor do they require the presence of H-NS. Instead, the VirB-dependent change in DNA supercoiling requires the interaction of VirB with its DNA binding site, a critical first step in VirB-dependent gene regulation. Using two complementary approaches, we show that VirB:DNA interactions in vitro introduce positive supercoils in plasmid DNA. Subsequently, by exploiting transcription-coupled DNA supercoiling, we reveal that a localized loss of negative supercoils is sufficient to alleviate H-NS-mediated transcriptional silencing, independently of VirB. Together, our findings provide novel insight into VirB, a central regulator of Shigella virulence and more broadly, a molecular mechanism that offsets H-NS-dependent silencing of transcription in bacteria.
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10
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Roberts DM, Anchimiuk A, Kloosterman TG, Murray H, Wu LJ, Gruber S, Errington J. Chromosome remodelling by SMC/Condensin in B. subtilis is regulated by monomeric Soj/ParA during growth and sporulation. Proc Natl Acad Sci U S A 2022; 119:e2204042119. [PMID: 36206370 PMCID: PMC9564211 DOI: 10.1073/pnas.2204042119] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/09/2022] [Indexed: 11/18/2022] Open
Abstract
SMC complexes, loaded at ParB-parS sites, are key mediators of chromosome organization in bacteria. ParA/Soj proteins interact with ParB/Spo0J in a pathway involving adenosine triphosphate (ATP)-dependent dimerization and DNA binding, facilitating chromosome segregation in bacteria. In Bacillus subtilis, ParA/Soj also regulates DNA replication initiation and along with ParB/Spo0J is involved in cell cycle changes during endospore formation. The first morphological stage in sporulation is the formation of an elongated chromosome structure called an axial filament. Here, we show that a major redistribution of SMC complexes drives axial filament formation in a process regulated by ParA/Soj. Furthermore, and unexpectedly, this regulation is dependent on monomeric forms of ParA/Soj that cannot bind DNA or hydrolyze ATP. These results reveal additional roles for ParA/Soj proteins in the regulation of SMC dynamics in bacteria and yet further complexity in the web of interactions involving chromosome replication, segregation and organization, controlled by ParAB and SMC.
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Affiliation(s)
- David M. Roberts
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Anna Anchimiuk
- Department of Fundamental Microbiology, University of Lausanne, Bâtiment Biophore, 015 Lausanne, Switzerland
| | - Tomas G. Kloosterman
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Heath Murray
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Ling Juan Wu
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Stephan Gruber
- Department of Fundamental Microbiology, University of Lausanne, Bâtiment Biophore, 015 Lausanne, Switzerland
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
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11
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Tišma M, Panoukidou M, Antar H, Soh YM, Barth R, Pradhan B, Barth A, van der Torre J, Michieletto D, Gruber S, Dekker C. ParB proteins can bypass DNA-bound roadblocks via dimer-dimer recruitment. SCIENCE ADVANCES 2022; 8:eabn3299. [PMID: 35767606 PMCID: PMC9242446 DOI: 10.1126/sciadv.abn3299] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The ParABS system is essential for prokaryotic chromosome segregation. After loading at parS on the genome, ParB (partition protein B) proteins rapidly redistribute to distances of ~15 kilobases from the loading site. It has remained puzzling how this large-distance spreading can occur along DNA loaded with hundreds of proteins. Using in vitro single-molecule fluorescence imaging, we show that ParB from Bacillus subtilis can load onto DNA distantly of parS, as loaded ParB molecules themselves are found to be able to recruit additional ParB proteins from bulk. Notably, this recruitment can occur in cis but also in trans, where, at low tensions within the DNA, newly recruited ParB can bypass roadblocks as it gets loaded to spatially proximal but genomically distant DNA regions. The data are supported by molecular dynamics simulations, which show that cooperative ParB-ParB recruitment can enhance spreading. ParS-independent recruitment explains how ParB can cover substantial genomic distance during chromosome segregation, which is vital for the bacterial cell cycle.
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Affiliation(s)
- Miloš Tišma
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Maria Panoukidou
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Hammam Antar
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Young-Min Soh
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Biswajit Pradhan
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Anders Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Davide Michieletto
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
- Corresponding author.
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12
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Osorio-Valeriano M, Altegoer F, Das CK, Steinchen W, Panis G, Connolley L, Giacomelli G, Feddersen H, Corrales-Guerrero L, Giammarinaro PI, Hanßmann J, Bramkamp M, Viollier PH, Murray S, Schäfer LV, Bange G, Thanbichler M. The CTPase activity of ParB determines the size and dynamics of prokaryotic DNA partition complexes. Mol Cell 2021; 81:3992-4007.e10. [PMID: 34562373 DOI: 10.1016/j.molcel.2021.09.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/27/2021] [Accepted: 08/31/2021] [Indexed: 01/29/2023]
Abstract
ParB-like CTPases mediate the segregation of bacterial chromosomes and low-copy number plasmids. They act as DNA-sliding clamps that are loaded at parS motifs in the centromere of target DNA molecules and spread laterally to form large nucleoprotein complexes serving as docking points for the DNA segregation machinery. Here, we solve crystal structures of ParB in the pre- and post-hydrolysis state and illuminate the catalytic mechanism of nucleotide hydrolysis. Moreover, we identify conformational changes that underlie the CTP- and parS-dependent closure of ParB clamps. The study of CTPase-deficient ParB variants reveals that CTP hydrolysis serves to limit the sliding time of ParB clamps and thus drives the establishment of a well-defined ParB diffusion gradient across the centromere whose dynamics are critical for DNA segregation. These findings clarify the role of the ParB CTPase cycle in partition complex assembly and function and thus advance our understanding of this prototypic CTP-dependent molecular switch.
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Affiliation(s)
- Manuel Osorio-Valeriano
- Department of Biology, University of Marburg, 35043 Marburg, Germany; Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Florian Altegoer
- Department of Chemistry, University of Marburg, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Chandan K Das
- Theoretical Chemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Wieland Steinchen
- Department of Chemistry, University of Marburg, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Gaël Panis
- Department of Microbiology and Molecular Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Lara Connolley
- Department of Systems & Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Giacomo Giacomelli
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Helge Feddersen
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | | | - Pietro I Giammarinaro
- Department of Chemistry, University of Marburg, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Juri Hanßmann
- Department of Biology, University of Marburg, 35043 Marburg, Germany
| | - Marc Bramkamp
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Patrick H Viollier
- Department of Microbiology and Molecular Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Seán Murray
- Department of Systems & Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Lars V Schäfer
- Theoretical Chemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Gert Bange
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany; Department of Chemistry, University of Marburg, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Martin Thanbichler
- Department of Biology, University of Marburg, 35043 Marburg, Germany; Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany.
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13
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The structure of the bacterial DNA segregation ATPase filament reveals the conformational plasticity of ParA upon DNA binding. Nat Commun 2021; 12:5166. [PMID: 34453062 PMCID: PMC8397727 DOI: 10.1038/s41467-021-25429-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/11/2021] [Indexed: 02/02/2023] Open
Abstract
The efficient segregation of replicated genetic material is an essential step for cell division. Bacterial cells use several evolutionarily-distinct genome segregation systems, the most common of which is the type I Par system. It consists of an adapter protein, ParB, that binds to the DNA cargo via interaction with the parS DNA sequence; and an ATPase, ParA, that binds nonspecific DNA and mediates cargo transport. However, the molecular details of how this system functions are not well understood. Here, we report the cryo-EM structure of the Vibrio cholerae ParA2 filament bound to DNA, as well as the crystal structures of this protein in various nucleotide states. These structures show that ParA forms a left-handed filament on DNA, stabilized by nucleotide binding, and that ParA undergoes profound structural rearrangements upon DNA binding and filament assembly. Collectively, our data suggest the structural basis for ParA’s cooperative binding to DNA and the formation of high ParA density regions on the nucleoid. ParA is an ATPase involved in the segregation of newly replicated DNA in bacteria. Here, structures of a ParA filament bound to DNA and of ParA in various nucleotide states offer insight into its conformational changes upon DNA binding and filament assembly, including the basis for ParA’s cooperative binding to DNA.
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14
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Jalal AS, Tran NT, Stevenson CE, Chimthanawala A, Badrinarayanan A, Lawson DM, Le TB. A CTP-dependent gating mechanism enables ParB spreading on DNA. eLife 2021; 10:69676. [PMID: 34397383 DOI: 10.1101/816959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/03/2021] [Indexed: 05/25/2023] Open
Abstract
Proper chromosome segregation is essential in all living organisms. The ParA-ParB-parS system is widely employed for chromosome segregation in bacteria. Previously, we showed that Caulobacter crescentus ParB requires cytidine triphosphate to escape the nucleation site parS and spread by sliding to the neighboring DNA (Jalal et al., 2020). Here, we provide the structural basis for this transition from nucleation to spreading by solving co-crystal structures of a C-terminal domain truncated C. crescentus ParB with parS and with a CTP analog. Nucleating ParB is an open clamp, in which parS is captured at the DNA-binding domain (the DNA-gate). Upon binding CTP, the N-terminal domain (NTD) self-dimerizes to close the NTD-gate of the clamp. The DNA-gate also closes, thus driving parS into a compartment between the DNA-gate and the C-terminal domain. CTP hydrolysis and/or the release of hydrolytic products are likely associated with reopening of the gates to release DNA and recycle ParB. Overall, we suggest a CTP-operated gating mechanism that regulates ParB nucleation, spreading, and recycling.
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Affiliation(s)
- Adam Sb Jalal
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Ngat T Tran
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Clare Em Stevenson
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich, United Kingdom
| | - Afroze Chimthanawala
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- SASTRA University, Thanjavur, Tamil Nadu, India
| | - Anjana Badrinarayanan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - David M Lawson
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich, United Kingdom
| | - Tung Bk Le
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
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15
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Jalal AS, Tran NT, Stevenson CE, Chimthanawala A, Badrinarayanan A, Lawson DM, Le TB. A CTP-dependent gating mechanism enables ParB spreading on DNA. eLife 2021; 10:69676. [PMID: 34397383 PMCID: PMC8367383 DOI: 10.7554/elife.69676] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/03/2021] [Indexed: 12/19/2022] Open
Abstract
Proper chromosome segregation is essential in all living organisms. The ParA-ParB-parS system is widely employed for chromosome segregation in bacteria. Previously, we showed that Caulobacter crescentus ParB requires cytidine triphosphate to escape the nucleation site parS and spread by sliding to the neighboring DNA (Jalal et al., 2020). Here, we provide the structural basis for this transition from nucleation to spreading by solving co-crystal structures of a C-terminal domain truncated C. crescentus ParB with parS and with a CTP analog. Nucleating ParB is an open clamp, in which parS is captured at the DNA-binding domain (the DNA-gate). Upon binding CTP, the N-terminal domain (NTD) self-dimerizes to close the NTD-gate of the clamp. The DNA-gate also closes, thus driving parS into a compartment between the DNA-gate and the C-terminal domain. CTP hydrolysis and/or the release of hydrolytic products are likely associated with reopening of the gates to release DNA and recycle ParB. Overall, we suggest a CTP-operated gating mechanism that regulates ParB nucleation, spreading, and recycling.
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Affiliation(s)
- Adam Sb Jalal
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Ngat T Tran
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Clare Em Stevenson
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich, United Kingdom
| | - Afroze Chimthanawala
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.,SASTRA University, Thanjavur, Tamil Nadu, India
| | - Anjana Badrinarayanan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - David M Lawson
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich, United Kingdom
| | - Tung Bk Le
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
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16
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Bell NAW, Haynes PJ, Brunner K, de Oliveira TM, Flocco MM, Hoogenboom BW, Molloy JE. Single-molecule measurements reveal that PARP1 condenses DNA by loop stabilization. SCIENCE ADVANCES 2021; 7:7/33/eabf3641. [PMID: 34380612 PMCID: PMC8357241 DOI: 10.1126/sciadv.abf3641] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 06/22/2021] [Indexed: 05/11/2023]
Abstract
Poly(ADP-ribose) polymerase 1 (PARP1) is an abundant nuclear enzyme that plays important roles in DNA repair, chromatin organization and transcription regulation. Although binding and activation of PARP1 by DNA damage sites has been extensively studied, little is known about how PARP1 binds to long stretches of undamaged DNA and how it could shape chromatin architecture. Here, using single-molecule techniques, we show that PARP1 binds and condenses undamaged, kilobase-length DNA subject to sub-piconewton mechanical forces. Stepwise decondensation at high force and DNA braiding experiments show that the condensation activity is due to the stabilization of DNA loops by PARP1. PARP inhibitors do not affect the level of condensation of undamaged DNA but act to block condensation reversal for damaged DNA in the presence of NAD+ Our findings suggest a mechanism for PARP1 in the organization of chromatin structure.
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Affiliation(s)
- Nicholas A W Bell
- The Francis Crick Institute, London NW1 1AT, UK.
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Philip J Haynes
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Molecular Sciences Research Hub, Department of Chemistry, Imperial College London, London W12 0BZ, UK
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Katharina Brunner
- The Francis Crick Institute, London NW1 1AT, UK
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Taiana Maia de Oliveira
- Mechanistic and Structural Biology, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Maria M Flocco
- Mechanistic and Structural Biology, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
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17
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Taylor JA, Seol Y, Budhathoki J, Neuman KC, Mizuuchi K. CTP and parS coordinate ParB partition complex dynamics and ParA-ATPase activation for ParABS-mediated DNA partitioning. eLife 2021; 10:65651. [PMID: 34286695 PMCID: PMC8357417 DOI: 10.7554/elife.65651] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 07/20/2021] [Indexed: 11/13/2022] Open
Abstract
ParABS partition systems, comprising the centromere-like DNA sequence parS, the parS-binding ParB-CTPase, and the nucleoid-binding ParA-ATPase, ensure faithful segregation of bacterial chromosomes and low-copy-number plasmids. F-plasmid partition complexes containing ParBF and parSF move by generating and following a local concentration gradient of nucleoid-bound ParAF. However, the process through which ParBF activates ParAF-ATPase has not been defined. We studied CTP- and parSF-modulated ParAF-ParBF complex assembly, in which DNA-bound ParAF-ATP dimers are activated for ATP hydrolysis by interacting with two ParBF N-terminal domains. CTP or parSF enhances the ATPase rate without significantly accelerating ParAF-ParBF complex assembly. Together, parSF and CTP accelerate ParAF-ParBF assembly without further significant increase in ATPase rate. Magnetic-tweezers experiments showed that CTP promotes multiple ParBF loading onto parSF-containing DNA, generating condensed partition complex-like assemblies. We propose that ParBF in the partition complex adopts a conformation that enhances ParBF-ParBF and ParAF-ParBF interactions promoting efficient partitioning.
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Affiliation(s)
- James A Taylor
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Yeonee Seol
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Jagat Budhathoki
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Keir C Neuman
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Kiyoshi Mizuuchi
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
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18
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Taylor JA, Seol Y, Budhathoki J, Neuman KC, Mizuuchi K. CTP and parS coordinate ParB partition complex dynamics and ParA-ATPase activation for ParABS-mediated DNA partitioning. eLife 2021; 10:65651. [PMID: 34286695 DOI: 10.1101/2021.01.24.427996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 07/20/2021] [Indexed: 05/25/2023] Open
Abstract
ParABS partition systems, comprising the centromere-like DNA sequence parS, the parS-binding ParB-CTPase, and the nucleoid-binding ParA-ATPase, ensure faithful segregation of bacterial chromosomes and low-copy-number plasmids. F-plasmid partition complexes containing ParBF and parSF move by generating and following a local concentration gradient of nucleoid-bound ParAF. However, the process through which ParBF activates ParAF-ATPase has not been defined. We studied CTP- and parSF-modulated ParAF-ParBF complex assembly, in which DNA-bound ParAF-ATP dimers are activated for ATP hydrolysis by interacting with two ParBF N-terminal domains. CTP or parSF enhances the ATPase rate without significantly accelerating ParAF-ParBF complex assembly. Together, parSF and CTP accelerate ParAF-ParBF assembly without further significant increase in ATPase rate. Magnetic-tweezers experiments showed that CTP promotes multiple ParBF loading onto parSF-containing DNA, generating condensed partition complex-like assemblies. We propose that ParBF in the partition complex adopts a conformation that enhances ParBF-ParBF and ParAF-ParBF interactions promoting efficient partitioning.
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Affiliation(s)
- James A Taylor
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Yeonee Seol
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Jagat Budhathoki
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Keir C Neuman
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Kiyoshi Mizuuchi
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
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19
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Balaguer FDA, Aicart-Ramos C, Fisher GL, de Bragança S, Martin-Cuevas EM, Pastrana CL, Dillingham MS, Moreno-Herrero F. CTP promotes efficient ParB-dependent DNA condensation by facilitating one-dimensional diffusion from parS. eLife 2021; 10:67554. [PMID: 34250901 PMCID: PMC8299390 DOI: 10.7554/elife.67554] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 07/09/2021] [Indexed: 12/19/2022] Open
Abstract
Faithful segregation of bacterial chromosomes relies on the ParABS partitioning system and the SMC complex. In this work, we used single-molecule techniques to investigate the role of cytidine triphosphate (CTP) binding and hydrolysis in the critical interaction between centromere-like parS DNA sequences and the ParB CTPase. Using a combined optical tweezers confocal microscope, we observe the specific interaction of ParB with parS directly. Binding around parS is enhanced by the presence of CTP or the non-hydrolysable analogue CTPγS. However, ParB proteins are also detected at a lower density in distal non-specific DNA. This requires the presence of a parS loading site and is prevented by protein roadblocks, consistent with one-dimensional diffusion by a sliding clamp. ParB diffusion on non-specific DNA is corroborated by direct visualization and quantification of movement of individual quantum dot labelled ParB. Magnetic tweezers experiments show that the spreading activity, which has an absolute requirement for CTP binding but not hydrolysis, results in the condensation of parS-containing DNA molecules at low nanomolar protein concentrations.
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Affiliation(s)
- Francisco de Asis Balaguer
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Clara Aicart-Ramos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Gemma Lm Fisher
- DNA:Protein Interactions Unit, School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, United Kingdom
| | - Sara de Bragança
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Eva M Martin-Cuevas
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Cesar L Pastrana
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Mark Simon Dillingham
- DNA:Protein Interactions Unit, School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, United Kingdom
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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20
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Cozzolino F, Iacobucci I, Monaco V, Monti M. Protein-DNA/RNA Interactions: An Overview of Investigation Methods in the -Omics Era. J Proteome Res 2021; 20:3018-3030. [PMID: 33961438 PMCID: PMC8280749 DOI: 10.1021/acs.jproteome.1c00074] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
![]()
The fields of application
of functional proteomics are not limited
to the study of protein–protein interactions; they also extend
to those involving protein complexes that bind DNA or RNA. These interactions
affect fundamental processes such as replication, transcription, and
repair in the case of DNA, as well as transport, translation, splicing,
and silencing in the case of RNA. Analytical or preparative experimental
approaches, both in vivo and in vitro, have been developed to isolate and identify DNA/RNA binding proteins
by exploiting the advantage of the affinity shown by these proteins
toward a specific oligonucleotide sequence. The present review proposes
an overview of the approaches most commonly employed in proteomics
applications for the identification of nucleic acid-binding proteins,
such as affinity purification (AP) protocols, EMSA, chromatin purification
methods, and CRISPR-based chromatin affinity purification, which are
generally associated with mass spectrometry methodologies for the
unbiased protein identification.
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Affiliation(s)
- Flora Cozzolino
- Department of Chemical Sciences, University Federico II of Naples, Strada Comunale Cinthia, 26, 80126 Naples, Italy.,CEINGE Advanced Biotechnologies, Via G. Salvatore 486, 80145 Naples, Italy
| | - Ilaria Iacobucci
- Department of Chemical Sciences, University Federico II of Naples, Strada Comunale Cinthia, 26, 80126 Naples, Italy.,CEINGE Advanced Biotechnologies, Via G. Salvatore 486, 80145 Naples, Italy
| | - Vittoria Monaco
- CEINGE Advanced Biotechnologies, Via G. Salvatore 486, 80145 Naples, Italy.,Interuniversity Consortium National Institute of Biostructures and Biosystems (INBB), Viale Medaglie d'Oro, 305-00136 Rome, Italy
| | - Maria Monti
- Department of Chemical Sciences, University Federico II of Naples, Strada Comunale Cinthia, 26, 80126 Naples, Italy.,CEINGE Advanced Biotechnologies, Via G. Salvatore 486, 80145 Naples, Italy
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21
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Perry CC, Ramos-Méndez J, Milligan JR. Boronated Condensed DNA as a Heterochromatic Radiation Target Model. Biomacromolecules 2021; 22:1675-1684. [PMID: 33750108 DOI: 10.1021/acs.biomac.1c00106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The compound 4-dihydroxyboryl-l-phenylalanine (BPA) has found use in clinical trials of boron neutron capture therapy (BNCT). Here, we have examined the interaction with DNA of an amide-blocked BPA derivative of hexa-l-arginine (Ac-BPA-Arg6-NH2). Physical and spectroscopic assays show that this peptide binds to and condenses DNA. The resulting condensates are highly resistant to the effects of nuclease incubation (68-fold) and gamma (38-fold) irradiation. Radioprotection was modeled by Monte Carlo track structure simulations of DNA single strand breaks (SSBs) with TOPAS-nBio. The differences between experimental and simulated SSB yields for uncondensed and condensed DNAs were ca. 2 and 18%, respectively. These observations indicate that the combination of a plasmid DNA target, the BPA-containing peptide, and track structure simulation provides a powerful approach to characterize DNA damage by the high-LET radiation associated with neutron capture on boron.
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Affiliation(s)
- Christopher C Perry
- Department of Basic Sciences, School of Medicine, Loma Linda University, 11085 Campus Street, Loma Linda, California 92350, United States
| | - José Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, 1600 Divisadero Street, San Francisco, California 94115, United States
| | - Jamie R Milligan
- Department of Basic Sciences, School of Medicine, Loma Linda University, 11085 Campus Street, Loma Linda, California 92350, United States
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22
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Physical Modeling of a Sliding Clamp Mechanism for the Spreading of ParB at Short Genomic Distance from Bacterial Centromere Sites. iScience 2020; 23:101861. [PMID: 33319179 PMCID: PMC7725951 DOI: 10.1016/j.isci.2020.101861] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/16/2020] [Accepted: 11/19/2020] [Indexed: 12/20/2022] Open
Abstract
Bacterial ParB partitioning proteins involved in chromosomes and low-copy-number plasmid segregation are cytosine triphosphate (CTP)-dependent molecular switches. CTP-binding converts ParB dimers to DNA clamps, allowing unidimensional diffusion along the DNA. This sliding property has been proposed to explain the ParB spreading over large distances from parS centromere sites where ParB is specifically loaded. We modeled such a "clamping and sliding" mechanism as a typical reaction-diffusion system, compared it to the F plasmid ParB DNA binding pattern, and found that it can account neither for the long range of ParB binding to DNA nor for the rapid assembly kinetics observed in vivo after parS duplication. Also, it predicts a strong effect on the F plasmid ParB binding pattern from the presence of a roadblock that is not observed in ChIP-sequencing (ChIP-seq). We conclude that although "clamping and sliding" can occur at short distances from parS, another mechanism must apply for ParB recruitment at larger genomic distances.
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23
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Guilhas B, Walter JC, Rech J, David G, Walliser NO, Palmeri J, Mathieu-Demaziere C, Parmeggiani A, Bouet JY, Le Gall A, Nollmann M. ATP-Driven Separation of Liquid Phase Condensates in Bacteria. Mol Cell 2020; 79:293-303.e4. [PMID: 32679076 DOI: 10.1016/j.molcel.2020.06.034] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 04/08/2020] [Accepted: 06/22/2020] [Indexed: 12/18/2022]
Abstract
Liquid-liquid phase-separated (LLPS) states are key to compartmentalizing components in the absence of membranes; however, it is unclear whether LLPS condensates are actively and specifically organized in the subcellular space and by which mechanisms. Here, we address this question by focusing on the ParABS DNA segregation system, composed of a centromeric-like sequence (parS), a DNA-binding protein (ParB), and a motor (ParA). We show that parS and ParB associate to form nanometer-sized, round condensates. ParB molecules diffuse rapidly within the nucleoid volume but display confined motions when trapped inside ParB condensates. Single ParB molecules are able to rapidly diffuse between different condensates, and nucleation is strongly favored by parS. Notably, the ParA motor is required to prevent the fusion of ParB condensates. These results describe a novel active mechanism that splits, segregates, and localizes non-canonical LLPS condensates in the subcellular space.
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Affiliation(s)
- Baptiste Guilhas
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université de Montpellier, 60 rue de Navacelles, 34090 Montpellier, France
| | - Jean-Charles Walter
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | - Jerome Rech
- LMGM, CBI, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Gabriel David
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | - Nils Ole Walliser
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | - John Palmeri
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | | | - Andrea Parmeggiani
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France; LPHI, CNRS, Université de Montpellier, Montpellier, France
| | - Jean-Yves Bouet
- LMGM, CBI, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Antoine Le Gall
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université de Montpellier, 60 rue de Navacelles, 34090 Montpellier, France.
| | - Marcelo Nollmann
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université de Montpellier, 60 rue de Navacelles, 34090 Montpellier, France.
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24
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Abstract
Proper chromosome segregation during cell division is essential in all domains of life. In the majority of bacterial species, faithful chromosome segregation is mediated by the tripartite ParABS system, consisting of an ATPase protein ParA, a CTPase and DNA-binding protein ParB, and a centromere-like parS site. The parS site is most often located near the origin of replication and is segregated first after chromosome replication. ParB nucleates on parS before binding to adjacent non-specific DNA to form a multimeric nucleoprotein complex. ParA interacts with ParB to drive the higher-order ParB–DNA complex, and hence the replicating chromosomes, to each daughter cell. Here, we review the various models for the formation of the ParABS complex and describe its role in segregating the origin-proximal region of the chromosome. Additionally, we discuss outstanding questions and challenges in understanding bacterial chromosome segregation.
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Affiliation(s)
- Adam S B Jalal
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Tung B K Le
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, United Kingdom
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25
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Osorio-Valeriano M, Altegoer F, Steinchen W, Urban S, Liu Y, Bange G, Thanbichler M. ParB-type DNA Segregation Proteins Are CTP-Dependent Molecular Switches. Cell 2020; 179:1512-1524.e15. [PMID: 31835030 DOI: 10.1016/j.cell.2019.11.015] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/22/2019] [Accepted: 11/12/2019] [Indexed: 11/24/2022]
Abstract
During cell division, newly replicated DNA is actively segregated to the daughter cells. In most bacteria, this process involves the DNA-binding protein ParB, which condenses the centromeric regions of sister DNA molecules into kinetochore-like structures that recruit the DNA partition ATPase ParA and the prokaroytic SMC/condensin complex. Here, we report the crystal structure of a ParB-like protein (PadC) that emerges to tightly bind the ribonucleotide CTP. The CTP-binding pocket of PadC is conserved in ParB and composed of signature motifs known to be essential for ParB function. We find that ParB indeed interacts with CTP and requires nucleotide binding for DNA condensation in vivo. We further show that CTP-binding modulates the affinity of ParB for centromeric parS sites, whereas parS recognition stimulates its CTPase activity. ParB proteins thus emerge as a new class of CTP-dependent molecular switches that act in concert with ATPases and GTPases to control fundamental cellular functions.
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Affiliation(s)
- Manuel Osorio-Valeriano
- Department of Biology, University of Marburg, 35043 Marburg, Germany; Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Florian Altegoer
- Department of Chemistry, University of Marburg, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Wieland Steinchen
- Department of Chemistry, University of Marburg, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Svenja Urban
- Department of Biology, University of Marburg, 35043 Marburg, Germany
| | - Ying Liu
- Department of Biology, University of Marburg, 35043 Marburg, Germany
| | - Gert Bange
- Department of Chemistry, University of Marburg, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany.
| | - Martin Thanbichler
- Department of Biology, University of Marburg, 35043 Marburg, Germany; Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany; Center for Synthetic Microbiology, 35043 Marburg, Germany.
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26
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Pióro M, Jakimowicz D. Chromosome Segregation Proteins as Coordinators of Cell Cycle in Response to Environmental Conditions. Front Microbiol 2020; 11:588. [PMID: 32351468 PMCID: PMC7174722 DOI: 10.3389/fmicb.2020.00588] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 03/18/2020] [Indexed: 12/11/2022] Open
Abstract
Chromosome segregation is a crucial stage of the cell cycle. In general, proteins involved in this process are DNA-binding proteins, and in most bacteria, ParA and ParB are the main players; however, some bacteria manage this process by employing other proteins, such as condensins. The dynamic interaction between ParA and ParB drives movement and exerts positioning of the chromosomal origin of replication (oriC) within the cell. In addition, both ParA and ParB were shown to interact with the other proteins, including those involved in cell division or cell elongation. The significance of these interactions for the progression of the cell cycle is currently under investigation. Remarkably, DNA binding by ParA and ParB as well as their interactions with protein partners conceivably may be modulated by intra- and extracellular conditions. This notion provokes the question of whether chromosome segregation can be regarded as a regulatory stage of the cell cycle. To address this question, we discuss how environmental conditions affect chromosome segregation and how segregation proteins influence other cell cycle processes.
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Affiliation(s)
- Monika Pióro
- Department of Molecular Microbiology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Dagmara Jakimowicz
- Department of Molecular Microbiology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
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27
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Jalal AS, Tran NT, Le TB. ParB spreading on DNA requires cytidine triphosphate in vitro. eLife 2020; 9:53515. [PMID: 32077854 PMCID: PMC7053999 DOI: 10.7554/elife.53515] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/19/2020] [Indexed: 01/08/2023] Open
Abstract
In all living organisms, it is essential to transmit genetic information faithfully to the next generation. The SMC-ParAB-parS system is widely employed for chromosome segregation in bacteria. A DNA-binding protein ParB nucleates on parS sites and must associate with neighboring DNA, a process known as spreading, to enable efficient chromosome segregation. Despite its importance, how the initial few ParB molecules nucleating at parS sites recruit hundreds of further ParB to spread is not fully understood. Here, we reconstitute a parS-dependent ParB spreading event using purified proteins from Caulobacter crescentus and show that CTP is required for spreading. We further show that ParB spreading requires a closed DNA substrate, and a DNA-binding transcriptional regulator can act as a roadblock to attenuate spreading unidirectionally in vitro. Our biochemical reconstitutions recapitulate many observed in vivo properties of ParB and opens up avenues to investigate the interactions between ParB-parS with ParA and SMC.
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Affiliation(s)
- Adam Sb Jalal
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Ngat T Tran
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Tung Bk Le
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
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28
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Kawalek A, Wawrzyniak P, Bartosik AA, Jagura-Burdzy G. Rules and Exceptions: The Role of Chromosomal ParB in DNA Segregation and Other Cellular Processes. Microorganisms 2020; 8:E105. [PMID: 31940850 PMCID: PMC7022226 DOI: 10.3390/microorganisms8010105] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 12/11/2022] Open
Abstract
The segregation of newly replicated chromosomes in bacterial cells is a highly coordinated spatiotemporal process. In the majority of bacterial species, a tripartite ParAB-parS system, composed of an ATPase (ParA), a DNA-binding protein (ParB), and its target(s) parS sequence(s), facilitates the initial steps of chromosome partitioning. ParB nucleates around parS(s) located in the vicinity of newly replicated oriCs to form large nucleoprotein complexes, which are subsequently relocated by ParA to distal cellular compartments. In this review, we describe the role of ParB in various processes within bacterial cells, pointing out interspecies differences. We outline recent progress in understanding the ParB nucleoprotein complex formation and its role in DNA segregation, including ori positioning and anchoring, DNA condensation, and loading of the structural maintenance of chromosome (SMC) proteins. The auxiliary roles of ParBs in the control of chromosome replication initiation and cell division, as well as the regulation of gene expression, are discussed. Moreover, we catalog ParB interacting proteins. Overall, this work highlights how different bacterial species adapt the DNA partitioning ParAB-parS system to meet their specific requirements.
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Affiliation(s)
| | | | | | - Grazyna Jagura-Burdzy
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (A.K.); (P.W.); (A.A.B.)
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29
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Kawalek A, Bartosik AA, Glabski K, Jagura-Burdzy G. Pseudomonas aeruginosa partitioning protein ParB acts as a nucleoid-associated protein binding to multiple copies of a parS-related motif. Nucleic Acids Res 2019; 46:4592-4606. [PMID: 29648658 PMCID: PMC5961200 DOI: 10.1093/nar/gky257] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 03/28/2018] [Indexed: 12/16/2022] Open
Abstract
ParA and ParB homologs are involved in accurate chromosome segregation in bacteria. ParBs participate in the separation of ori domains by binding to parS palindromes, mainly localized close to oriC. In Pseudomonas aeruginosa neither ParB deficiency nor modification of all 10 parSs is lethal. However, such mutants show not only defects in chromosome segregation but also growth retardation and motility dysfunctions. Moreover, a lack of parB alters expression of over 1000 genes, suggesting that ParB could interact with the chromosome outside its canonical parS targets. Here, we show that indeed ParB binds specifically to hundreds of sites in the genome. ChIP-seq analysis revealed 420 ParB-associated regions in wild-type strain and around 1000 in a ParB-overproducing strain and in various parS mutants. The vast majority of the ParB-enriched loci contained a heptanucleotide motif corresponding to one arm of the parS palindrome. All previously postulated parSs, except parS5, interacted with ParB in vivo. Whereas the ParB binding to the four parS sites closest to oriC, parS1-4, is involved in chromosome segregation, its genome-wide interactions with hundreds of parS half-sites could affect chromosome topology, compaction and gene expression, thus allowing P. aeruginosa ParB to be classified as a nucleoid-associated protein.
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Affiliation(s)
- Adam Kawalek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Aneta A Bartosik
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Krzysztof Glabski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Grazyna Jagura-Burdzy
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Pawinskiego 5a, 02-106 Warsaw, Poland
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30
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Tran NT, Stevenson CE, Som NF, Thanapipatsiri A, Jalal ASB, Le TBK. Permissive zones for the centromere-binding protein ParB on the Caulobacter crescentus chromosome. Nucleic Acids Res 2019; 46:1196-1209. [PMID: 29186514 PMCID: PMC5815017 DOI: 10.1093/nar/gkx1192] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 11/16/2017] [Indexed: 12/22/2022] Open
Abstract
Proper chromosome segregation is essential in all living organisms. In Caulobacter crescentus, the ParA–ParB–parS system is required for proper chromosome segregation and cell viability. The bacterial centromere-like parS DNA locus is the first to be segregated following chromosome replication. parS is bound by ParB protein, which in turn interacts with ParA to partition the ParB-parS nucleoprotein complex to each daughter cell. Here, we investigated the genome-wide distribution of ParB on the Caulobacter chromosome using a combination of in vivo chromatin immunoprecipitation (ChIP-seq) and in vitro DNA affinity purification with deep sequencing (IDAP-seq). We confirmed two previously identified parS sites and discovered at least three more sites that cluster ∼8 kb from the origin of replication. We showed that Caulobacter ParB nucleates at parS sites and associates non-specifically with ∼10 kb flanking DNA to form a high-order nucleoprotein complex on the left chromosomal arm. Lastly, using transposon mutagenesis coupled with deep sequencing (Tn-seq), we identified a ∼500 kb region surrounding the native parS cluster that is tolerable to the insertion of a second parS cluster without severely affecting cell viability. Our results demonstrate that the genomic distribution of parS sites is highly restricted and is crucial for chromosome segregation in Caulobacter.
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Affiliation(s)
- Ngat T Tran
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK
| | - Clare E Stevenson
- Department of Biological Chemistry, John Innes Centre, Norwich NR4 7UH, UK
| | - Nicolle F Som
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK
| | | | - Adam S B Jalal
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK
| | - Tung B K Le
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK
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31
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Madariaga-Marcos J, Pastrana CL, Fisher GL, Dillingham MS, Moreno-Herrero F. ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements. eLife 2019; 8:43812. [PMID: 30907359 PMCID: PMC6433461 DOI: 10.7554/elife.43812] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/09/2019] [Indexed: 02/04/2023] Open
Abstract
Bacillus subtilis ParB forms multimeric networks involving non-specific DNA binding leading to DNA condensation. Previously, we found that an excess of the free C-terminal domain (CTD) of ParB impeded DNA condensation or promoted decondensation of pre-assembled networks (Fisher et al., 2017). However, interpretation of the molecular basis for this phenomenon was complicated by our inability to uncouple protein binding from DNA condensation. Here, we have combined lateral magnetic tweezers with TIRF microscopy to simultaneously control the restrictive force against condensation and to visualise ParB protein binding by fluorescence. At non-permissive forces for condensation, ParB binds non-specifically and highly dynamically to DNA. Our new approach concluded that the free CTD blocks the formation of ParB networks by heterodimerisation with full length DNA-bound ParB. This strongly supports a model in which the CTD acts as a key bridging interface between distal DNA binding loci within ParB networks.
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Affiliation(s)
- Julene Madariaga-Marcos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Cesar L Pastrana
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Gemma Lm Fisher
- DNA:Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Mark Simon Dillingham
- DNA:Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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32
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Marczynski GT, Petit K, Patel P. Crosstalk Regulation Between Bacterial Chromosome Replication and Chromosome Partitioning. Front Microbiol 2019; 10:279. [PMID: 30863373 PMCID: PMC6399470 DOI: 10.3389/fmicb.2019.00279] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 02/04/2019] [Indexed: 12/14/2022] Open
Abstract
Despite much effort, the bacterial cell cycle has proved difficult to study and understand. Bacteria do not conform to the standard eukaryotic model of sequential cell-cycle phases. Instead, for example, bacteria overlap their phases of chromosome replication and chromosome partitioning. In “eukaryotic terms,” bacteria simultaneously perform “S-phase” and “mitosis” whose coordination is absolutely required for rapid growth and survival. In this review, we focus on the signaling “crosstalk,” meaning the signaling mechanisms that advantageously commit bacteria to start both chromosome replication and chromosome partitioning. After briefly reviewing the molecular mechanisms of replication and partitioning, we highlight the crosstalk research from Bacillus subtilis, Vibrio cholerae, and Caulobacter crescentus. As the initiator of chromosome replication, DnaA also mediates crosstalk in each of these model bacteria but not always in the same way. We next focus on the C. crescentus cell cycle and describe how it is revealing novel crosstalk mechanisms. Recent experiments show that the novel nucleoid associated protein GapR has a special role(s) in starting and separating the replicating chromosomes, so that upon asymmetric cell division, the new chromosomes acquire different fates in C. crescentus’s distinct replicating and non-replicating cell types. The C. crescentus PopZ protein forms a special cell-pole organizing matrix that anchors the chromosomes through their centromere-like DNA sequences near the origin of replication. We also describe how PopZ anchors and interacts with several key cell-cycle regulators, thereby providing an organized subcellular environment for more novel crosstalk mechanisms.
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Affiliation(s)
- Gregory T Marczynski
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Kenny Petit
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Priya Patel
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
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33
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Debaugny RE, Sanchez A, Rech J, Labourdette D, Dorignac J, Geniet F, Palmeri J, Parmeggiani A, Boudsocq F, Anton Leberre V, Walter JC, Bouet JY. A conserved mechanism drives partition complex assembly on bacterial chromosomes and plasmids. Mol Syst Biol 2018; 14:e8516. [PMID: 30446599 PMCID: PMC6238139 DOI: 10.15252/msb.20188516] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/22/2018] [Indexed: 11/29/2022] Open
Abstract
Chromosome and plasmid segregation in bacteria are mostly driven by ParABS systems. These DNA partitioning machineries rely on large nucleoprotein complexes assembled on centromere sites (parS). However, the mechanism of how a few parS-bound ParB proteins nucleate the formation of highly concentrated ParB clusters remains unclear despite several proposed physico-mathematical models. We discriminated between these different models by varying some key parameters in vivo using the F plasmid partition system. We found that "Nucleation & caging" is the only coherent model recapitulating in vivo data. We also showed that the stochastic self-assembly of partition complexes (i) is a robust mechanism, (ii) does not directly involve ParA ATPase, (iii) results in a dynamic structure of discrete size independent of ParB concentration, and (iv) is not perturbed by active transcription but is by protein complexes. We refined the "Nucleation & caging" model and successfully applied it to the chromosomally encoded Par system of Vibrio cholerae, indicating that this stochastic self-assembly mechanism is widely conserved from plasmids to chromosomes.
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Affiliation(s)
- Roxanne E Debaugny
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Centre National de la Recherche Scientifique (CNRS), Université de Toulouse, UPS, Toulouse, France
| | - Aurore Sanchez
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Centre National de la Recherche Scientifique (CNRS), Université de Toulouse, UPS, Toulouse, France
| | - Jérôme Rech
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Centre National de la Recherche Scientifique (CNRS), Université de Toulouse, UPS, Toulouse, France
| | | | - Jérôme Dorignac
- Laboratoire Charles Coulomb, CNRS-Université Montpellier, Montpellier, France
| | - Frédéric Geniet
- Laboratoire Charles Coulomb, CNRS-Université Montpellier, Montpellier, France
| | - John Palmeri
- Laboratoire Charles Coulomb, CNRS-Université Montpellier, Montpellier, France
| | - Andrea Parmeggiani
- Laboratoire Charles Coulomb, CNRS-Université Montpellier, Montpellier, France
- Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS-Université Montpellier, Montpellier, France
| | - François Boudsocq
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Centre National de la Recherche Scientifique (CNRS), Université de Toulouse, UPS, Toulouse, France
| | | | - Jean-Charles Walter
- Laboratoire Charles Coulomb, CNRS-Université Montpellier, Montpellier, France
| | - Jean-Yves Bouet
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Centre National de la Recherche Scientifique (CNRS), Université de Toulouse, UPS, Toulouse, France
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34
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Martín-García B, Martín-González A, Carrasco C, Hernández-Arriaga AM, Ruíz-Quero R, Díaz-Orejas R, Aicart-Ramos C, Moreno-Herrero F, Oliva MA. The TubR-centromere complex adopts a double-ring segrosome structure in Type III partition systems. Nucleic Acids Res 2018; 46:5704-5716. [PMID: 29762781 PMCID: PMC6009700 DOI: 10.1093/nar/gky370] [Citation(s) in RCA: 7] [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: 01/23/2018] [Accepted: 04/27/2018] [Indexed: 11/26/2022] Open
Abstract
In prokaryotes, the centromere is a specialized segment of DNA that promotes the assembly of the segrosome upon binding of the Centromere Binding Protein (CBP). The segrosome structure exposes a specific surface for the interaction of the CBP with the motor protein that mediates DNA movement during cell division. Additionally, the CBP usually controls the transcriptional regulation of the segregation system as a cell cycle checkpoint. Correct segrosome functioning is therefore indispensable for accurate DNA segregation. Here, we combine biochemical reconstruction and structural and biophysical analysis to bring light to the architecture of the segrosome complex in Type III partition systems. We present the particular features of the centromere site, tubC, of the model system encoded in Clostridium botulinum prophage c-st. We find that the split centromere site contains two different iterons involved in the binding and spreading of the CBP, TubR. The resulting nucleoprotein complex consists of a novel double-ring structure that covers part of the predicted promoter. Single molecule data provides a mechanism for the formation of the segrosome structure based on DNA bending and unwinding upon TubR binding.
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Affiliation(s)
- Bárbara Martín-García
- Department of Structural and Chemical Biology, CSIC-Centro de Investigaciones Biológicas, Madrid 28040, Spain
| | | | - Carolina Carrasco
- Department of Macromolecular Structures, CSIC-Centro Nacional de Biotecnología, Madrid 28049, Spain
| | - Ana M Hernández-Arriaga
- Department of Structural and Chemical Biology, CSIC-Centro de Investigaciones Biológicas, Madrid 28040, Spain
| | - Rubén Ruíz-Quero
- Department of Structural and Chemical Biology, CSIC-Centro de Investigaciones Biológicas, Madrid 28040, Spain
| | - Ramón Díaz-Orejas
- Department of Structural and Chemical Biology, CSIC-Centro de Investigaciones Biológicas, Madrid 28040, Spain
| | - Clara Aicart-Ramos
- Department of Macromolecular Structures, CSIC-Centro Nacional de Biotecnología, Madrid 28049, Spain
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, CSIC-Centro Nacional de Biotecnología, Madrid 28049, Spain
| | - María A Oliva
- Department of Structural and Chemical Biology, CSIC-Centro de Investigaciones Biológicas, Madrid 28040, Spain
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35
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Madariaga-Marcos J, Hormeño S, Pastrana CL, Fisher GLM, Dillingham MS, Moreno-Herrero F. Force determination in lateral magnetic tweezers combined with TIRF microscopy. NANOSCALE 2018; 10:4579-4590. [PMID: 29461549 PMCID: PMC5831119 DOI: 10.1039/c7nr07344e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 12/07/2017] [Indexed: 06/08/2023]
Abstract
Combining single-molecule techniques with fluorescence microscopy has attracted much interest because it allows the correlation of mechanical measurements with directly visualized DNA : protein interactions. In particular, its combination with total internal reflection fluorescence microscopy (TIRF) is advantageous because of the high signal-to-noise ratio this technique achieves. This, however, requires stretching long DNA molecules across the surface of a flow cell to maximize polymer exposure to the excitation light. In this work, we develop a module to laterally stretch DNA molecules at a constant force, which can be easily implemented in regular or combined magnetic tweezers (MT)-TIRF setups. The pulling module is further characterized in standard flow cells of different thicknesses and glass capillaries, using two types of micrometer size superparamagnetic beads, long DNA molecules, and a home-built device to rotate capillaries with mrad precision. The force range achieved by the magnetic pulling module was between 0.1 and 30 pN. A formalism for estimating forces in flow-stretched tethered beads is also proposed, and the results compared with those of lateral MT, demonstrating that lateral MT achieve higher forces with lower dispersion. Finally, we show the compatibility with TIRF microscopy and the parallelization of measurements by characterizing DNA binding by the centromere-binding protein ParB from Bacillus subtilis. Simultaneous MT pulling and fluorescence imaging demonstrate the non-specific binding of BsParB on DNA under conditions restrictive to condensation.
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Affiliation(s)
- J. Madariaga-Marcos
- Department of Macromolecular Structures , Centro Nacional de Biotecnología , Consejo Superior de Investigaciones Científicas , 28049 Cantoblanco , Madrid , Spain .
| | - S. Hormeño
- Department of Macromolecular Structures , Centro Nacional de Biotecnología , Consejo Superior de Investigaciones Científicas , 28049 Cantoblanco , Madrid , Spain .
| | - C. L. Pastrana
- Department of Macromolecular Structures , Centro Nacional de Biotecnología , Consejo Superior de Investigaciones Científicas , 28049 Cantoblanco , Madrid , Spain .
| | - G. L. M. Fisher
- DNA:Protein Interactions Unit , School of Biochemistry , Biomedical Sciences Building , University of Bristol , Bristol , BS8 1TD , UK
| | - M. S. Dillingham
- DNA:Protein Interactions Unit , School of Biochemistry , Biomedical Sciences Building , University of Bristol , Bristol , BS8 1TD , UK
| | - F. Moreno-Herrero
- Department of Macromolecular Structures , Centro Nacional de Biotecnología , Consejo Superior de Investigaciones Científicas , 28049 Cantoblanco , Madrid , Spain .
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36
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Gao EJ, Meng B, Su JQ, Peng TT, Qi ZZ, Jia B, Feng YH, Zhu MC. Structure, DNA bonding, and biological activity of a novel Pb(II) complex of 1,1-bis(5-(pyrazin-2-yl)-1,2,4-triazol-3-yl) methane. J STRUCT CHEM+ 2018. [DOI: 10.1134/s0022476617080121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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37
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Song D, Rodrigues K, Graham TGW, Loparo JJ. A network of cis and trans interactions is required for ParB spreading. Nucleic Acids Res 2017; 45:7106-7117. [PMID: 28407103 PMCID: PMC5499601 DOI: 10.1093/nar/gkx271] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 04/05/2017] [Indexed: 11/12/2022] Open
Abstract
Most bacteria utilize the highly conserved parABS partitioning system in plasmid and chromosome segregation. This system depends on a DNA-binding protein ParB, which binds specifically to the centromere DNA sequence parS and to adjacent non-specific DNA over multiple kilobases in a phenomenon called spreading. Previous single-molecule experiments in combination with genetic, biochemical and computational studies have argued that ParB spreading requires cooperative interactions between ParB dimers including DNA bridging and possible nearest-neighbor interactions. A recent structure of a ParB homolog co-crystallized with parS revealed that ParB dimers tetramerize to form a higher order nucleoprotein complex. Using this structure as a guide, we systematically ablated a series of proposed intermolecular interactions in the Bacillus subtilis ParB (BsSpo0J) and characterized their effect on spreading using both in vivo and in vitro assays. In particular, we measured DNA compaction mediated by BsSpo0J using a recently developed single-molecule method to simultaneously visualize protein binding on single DNA molecules and changes in DNA conformation without protein labeling. Our results indicate that residues acting as hubs for multiple interactions frequently led to the most severe spreading defects when mutated, and that a network of both cis and trans interactions between ParB dimers is necessary for spreading.
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Affiliation(s)
- Dan Song
- Harvard Biophysics Program, Harvard Medical School, Boston MA 02115, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Kristen Rodrigues
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.,Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Thomas G W Graham
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.,Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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38
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Qian C, Fu H, Kovalchik KA, Li H, Chen DDY. Specific Binding Constant and Stoichiometry Determination in Free Solution by Mass Spectrometry and Capillary Electrophoresis Frontal Analysis. Anal Chem 2017; 89:9483-9490. [DOI: 10.1021/acs.analchem.7b02443] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Cheng Qian
- National
and Local Joint Engineering Research Center of Biomedical Functional
Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional
Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
- Department
of Chemistry, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Hengqing Fu
- National
and Local Joint Engineering Research Center of Biomedical Functional
Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional
Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Kevin A. Kovalchik
- Department
of Chemistry, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Huihui Li
- National
and Local Joint Engineering Research Center of Biomedical Functional
Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional
Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
| | - David Da Yong Chen
- National
and Local Joint Engineering Research Center of Biomedical Functional
Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional
Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China
- Department
of Chemistry, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
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39
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Tardin C. The mechanics of DNA loops bridged by proteins unveiled by single-molecule experiments. Biochimie 2017; 142:80-92. [PMID: 28804000 DOI: 10.1016/j.biochi.2017.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 08/06/2017] [Indexed: 12/28/2022]
Abstract
Protein-induced DNA bridging and looping is a common mechanism for various and essential processes in bacterial chromosomes. This mechanism is preserved despite the very different bacterial conditions and their expected influence on the thermodynamic and kinetic characteristics of the bridge formation and stability. Over the last two decades, single-molecule techniques carried out on in vitro DNA systems have yielded valuable results which, in combination with theoretical works, have clarified the effects of different parameters of nucleoprotein complexes on the protein-induced DNA bridging and looping process. In this review, I will outline the features that can be measured for such processes with various single-molecule techniques in use in the field. I will then describe both the experimental results and the theoretical models that illuminate the contribution of the DNA molecule itself as well as that of the bridging proteins in the DNA looping mechanism at play in the nucleoid of E. coli.
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Affiliation(s)
- Catherine Tardin
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, France.
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40
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Protein-nucleic acids interactions: new ways of connecting structure, dynamics and function. Biophys Rev 2017; 9:289-291. [PMID: 28776257 DOI: 10.1007/s12551-017-0284-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 07/19/2017] [Indexed: 12/26/2022] Open
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41
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Kawalek A, Glabski K, Bartosik AA, Fogtman A, Jagura-Burdzy G. Increased ParB level affects expression of stress response, adaptation and virulence operons and potentiates repression of promoters adjacent to the high affinity binding sites parS3 and parS4 in Pseudomonas aeruginosa. PLoS One 2017; 12:e0181726. [PMID: 28732084 PMCID: PMC5521831 DOI: 10.1371/journal.pone.0181726] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 07/06/2017] [Indexed: 12/14/2022] Open
Abstract
Similarly to its homologs in other bacteria, Pseudomonas aeruginosa partitioning protein ParB facilitates segregation of newly replicated chromosomes. Lack of ParB is not lethal but results in increased frequency of anucleate cells production, longer division time, cell elongation, altered colony morphology and defective swarming and swimming motility. Unlike in other bacteria, inactivation of parB leads to major changes of the transcriptome, suggesting that, directly or indirectly, ParB plays a role in regulation of gene expression in this organism. ParB overproduction affects growth rate, cell division and motility in a similar way as ParB deficiency. To identify primary ParB targets, here we analysed the impact of a slight increase in ParB level on P. aeruginosa transcriptome. ParB excess, which does not cause changes in growth rate and chromosome segregation, significantly alters the expression of 176 loci. Most notably, the mRNA level of genes adjacent to high affinity ParB binding sites parS1-4 close to oriC is reduced. Conversely, in cells lacking either parB or functional parS sequences the orfs adjacent to parS3 and parS4 are upregulated, indicating that direct ParB- parS3/parS4 interactions repress the transcription in this region. In addition, increased ParB level brings about repression or activation of numerous genes including several transcriptional regulators involved in SOS response, virulence and adaptation. Overall, our data support the role of partitioning protein ParB as a transcriptional regulator in Pseudomonas aeruginosa.
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Affiliation(s)
- Adam Kawalek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland
| | - Krzysztof Glabski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland
| | - Aneta Agnieszka Bartosik
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland
| | - Anna Fogtman
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Laboratory of Microarray Analysis, Warsaw, Poland
| | - Grazyna Jagura-Burdzy
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland
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42
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Fisher GLM, Pastrana CL, Higman VA, Koh A, Taylor JA, Butterer A, Craggs T, Sobott F, Murray H, Crump MP, Moreno-Herrero F, Dillingham MS. The structural basis for dynamic DNA binding and bridging interactions which condense the bacterial centromere. eLife 2017; 6:e28086. [PMID: 29244022 PMCID: PMC5731820 DOI: 10.7554/elife.28086] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 12/02/2017] [Indexed: 01/20/2023] Open
Abstract
The ParB protein forms DNA bridging interactions around parS to condense DNA and earmark the bacterial chromosome for segregation. The molecular mechanism underlying the formation of these ParB networks is unclear. We show here that while the central DNA binding domain is essential for anchoring at parS, this interaction is not required for DNA condensation. Structural analysis of the C-terminal domain reveals a dimer with a lysine-rich surface that binds DNA non-specifically and is essential for DNA condensation in vitro. Mutation of either the dimerisation or the DNA binding interface eliminates ParB-GFP foci formation in vivo. Moreover, the free C-terminal domain can rapidly decondense ParB networks independently of its ability to bind DNA. Our work reveals a dual role for the C-terminal domain of ParB as both a DNA binding and bridging interface, and highlights the dynamic nature of ParB networks in Bacillus subtilis.
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Affiliation(s)
- Gemma LM Fisher
- DNA:protein Interactions Unit, School of BiochemistryUniversity of BristolBristolUnited Kingdom
| | - César L Pastrana
- Department of Macromolecular StructuresCentro Nacional de Biotecnologia, Consejo Superior de Investigaciones CientificasMadridSpain
| | | | - Alan Koh
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastleUnited Kingdom
| | - James A Taylor
- DNA:protein Interactions Unit, School of BiochemistryUniversity of BristolBristolUnited Kingdom
| | - Annika Butterer
- Biomolecular and Analytical Mass Spectrometry Group, Department of ChemistryUniversity of AntwerpAntwerpenBelgium
| | - Timothy Craggs
- Department of ChemistryUniversity of SheffieldSheffieldUnited Kingdom
| | - Frank Sobott
- Biomolecular and Analytical Mass Spectrometry Group, Department of ChemistryUniversity of AntwerpAntwerpenBelgium,Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUnited Kingdom,School of Molecular and Cellular BiologyUniversity of LeedsLeedsUnited Kingdom
| | - Heath Murray
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastleUnited Kingdom
| | - Matthew P Crump
- School of ChemistryUniversity of BristolBristolUnited Kingdom
| | - Fernando Moreno-Herrero
- Department of Macromolecular StructuresCentro Nacional de Biotecnologia, Consejo Superior de Investigaciones CientificasMadridSpain
| | - Mark S Dillingham
- DNA:protein Interactions Unit, School of BiochemistryUniversity of BristolBristolUnited Kingdom
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43
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Lagage V, Boccard F, Vallet-Gely I. Regional Control of Chromosome Segregation in Pseudomonas aeruginosa. PLoS Genet 2016; 12:e1006428. [PMID: 27820816 PMCID: PMC5098823 DOI: 10.1371/journal.pgen.1006428] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/15/2016] [Indexed: 01/31/2023] Open
Abstract
Chromosome segregation in bacteria occurs concomitantly with DNA replication, and the duplicated regions containing the replication origin oriC are generally the first to separate and migrate to their final specific location inside the cell. In numerous bacterial species, a three-component partition machinery called the ParABS system is crucial for chromosome segregation. This is the case in the gammaproteobacterium Pseudomonas aeruginosa, where impairing the ParABS system is very detrimental for growth, as it increases the generation time and leads to the formation of anucleate cells and to oriC mispositioning inside the cell. In this study, we investigate in vivo the ParABS system in P. aeruginosa. Using chromatin immuno-precipitation coupled with high throughput sequencing, we show that ParB binds to four parS site located within 15 kb of oriC in vivo, and that this binding promotes the formation of a high order nucleoprotein complex. We show that one parS site is enough to prevent anucleate cell formation, therefore for correct chromosome segregation. By displacing the parS site from its native position on the chromosome, we demonstrate that parS is the first chromosomal locus to be separated upon DNA replication, which indicates that it is the site of force exertion of the segregation process. We identify a region of approximatively 650 kb surrounding oriC in which the parS site must be positioned for chromosome segregation to proceed correctly, and we called it “competence zone” of the parS site. Mutant strains that have undergone specific genetic rearrangements allow us to propose that the distance between oriC and parS defines this “competence zone”. Implications for the control of chromosome segregation in P. aeruginosa are discussed. Accurate transmission of the genetic information relies on replication and segregation, two processes essential to all living organisms. In bacteria, these processes occur concomitantly. Replication of the bacterial circular chromosome initiates at a single specific sequence called oriC, and proceed bi-directionally along the chromosome arms. A partition system called ParABS is involved in chromosome segregation in many bacteria. It involves the binding of the ParB protein to parS sequences, which are often found in the close vicinity of oriC. The importance of this system for chromosome segregation varies according to species, ranging from essential to dispensable. In Pseudomonas aeruginosa, an important opportunistic pathogen, the ParABS system plays an important role in chromosome segregation, as mutants affected in this system present a severe growth defect as well as anucleate cells formation, but is not essential. In this study, we characterize the activity of the different determinants of the ParABS system in P. aeruginosa and demonstrate that it is critical for the parS site to be located close to oriC, which suggest that the timing of separation of regions close to oriC after replication is important, and that it could be a function of the ParABS system to keep this timing.
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Affiliation(s)
- Valentine Lagage
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
| | - Frédéric Boccard
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
- * E-mail: (IVG); (FB)
| | - Isabelle Vallet-Gely
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
- * E-mail: (IVG); (FB)
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44
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Funnell BE. ParB Partition Proteins: Complex Formation and Spreading at Bacterial and Plasmid Centromeres. Front Mol Biosci 2016; 3:44. [PMID: 27622187 PMCID: PMC5002424 DOI: 10.3389/fmolb.2016.00044] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/15/2016] [Indexed: 11/13/2022] Open
Abstract
In bacteria, active partition systems contribute to the faithful segregation of both chromosomes and low-copy-number plasmids. Each system depends on a site-specific DNA binding protein to recognize and assemble a partition complex at a centromere-like site, commonly called parS. Many plasmid, and all chromosomal centromere-binding proteins are dimeric helix-turn-helix DNA binding proteins, which are commonly named ParB. Although the overall sequence conservation among ParBs is not high, the proteins share similar domain and functional organization, and they assemble into similar higher-order complexes. In vivo, ParBs "spread," that is, DNA binding extends away from the parS site into the surrounding non-specific DNA, a feature that reflects higher-order complex assembly. ParBs bridge and pair DNA at parS and non-specific DNA sites. ParB dimers interact with each other via flexible conformations of an N-terminal region. This review will focus on the properties of the HTH centromere-binding protein, in light of recent experimental evidence and models that are adding to our understanding of how these proteins assemble into large and dynamic partition complexes at and around their specific DNA sites.
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Affiliation(s)
- Barbara E Funnell
- Department of Molecular Genetics, University of Toronto Toronto, ON, Canada
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45
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Pastrana CL, Carrasco C, Akhtar P, Leuba SH, Khan SA, Moreno-Herrero F. Force and twist dependence of RepC nicking activity on torsionally-constrained DNA molecules. Nucleic Acids Res 2016; 44:8885-8896. [PMID: 27488190 PMCID: PMC5062986 DOI: 10.1093/nar/gkw689] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/22/2016] [Indexed: 11/14/2022] Open
Abstract
Many bacterial plasmids replicate by an asymmetric rolling-circle mechanism that requires sequence-specific recognition for initiation, nicking of one of the template DNA strands and unwinding of the duplex prior to subsequent leading strand DNA synthesis. Nicking is performed by a replication-initiation protein (Rep) that directly binds to the plasmid double-stranded origin and remains covalently bound to its substrate 5′-end via a phosphotyrosine linkage. It has been proposed that the inverted DNA sequences at the nick site form a cruciform structure that facilitates DNA cleavage. However, the role of Rep proteins in the formation of this cruciform and the implication for its nicking and religation functions is unclear. Here, we have used magnetic tweezers to directly measure the DNA nicking and religation activities of RepC, the replication initiator protein of plasmid pT181, in plasmid sized and torsionally-constrained linear DNA molecules. Nicking by RepC occurred only in negatively supercoiled DNA and was force- and twist-dependent. Comparison with a type IB topoisomerase in similar experiments highlighted a relatively inefficient religation activity of RepC. Based on the structural modeling of RepC and on our experimental evidence, we propose a model where RepC nicking activity is passive and dependent upon the supercoiling degree of the DNA substrate.
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Affiliation(s)
- Cesar L Pastrana
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049 Cantoblanco, Madrid, Spain
| | - Carolina Carrasco
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049 Cantoblanco, Madrid, Spain
| | - Parvez Akhtar
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219, USA
| | - Sanford H Leuba
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Saleem A Khan
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219, USA
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049 Cantoblanco, Madrid, Spain
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46
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Dmowski M, Kern-Zdanowicz I. Omega (ParB) binding sites together with the RNA polymerase-recognized sequence are essential for centromeric functions of the Pωregion in the partition system of pSM19035. MICROBIOLOGY-SGM 2016; 162:1114-1124. [PMID: 27177883 DOI: 10.1099/mic.0.000308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Partition systems contribute to stable plasmid inheritance in bacteria through the active separation of DNA molecules to daughter cells, and the centromeric sequence located either upstream or downstream of canonical partition operons plays an important role in this process. A specific DNA-binding protein binds to this sequence and interacts with the motor NTPase protein to form a nucleoprotein complex. The inc18-family plasmid pSM19035 is partitioned by products of δ and ω genes, with δ encoding a Walker-type ATPase and ω encoding a DNA-binding protein. As the two genes are transcribed separately, this system differs from others in its organization; nonetheless, expression of these genes is regulated by Omega, which also regulates the copy number of the plasmid (by controlling copS gene expression). Protein Omega specifically recognizes WATCACW heptad repeats. In this study, we constructed a synthetic δω operon to enable an analysis of the centromeric functions of Omega-binding sites Pδ, Pω and PcopS, discrete from their promoter functions. Our results show that these three regions do not support plasmid stabilization equally. We demonstrate that the Pω site alone can simultaneously drive the expression of partition genes from the synthetic δω operon and act as a unique centromeric sequence to promote the most efficient plasmid partitioning. Moreover, Pω can support the centromeric function in concert with the synthetic δω operon expressed from a heterologous promoter demonstrating that Pω is the main centromeric sequence of the δ-ω partition system. Additionally, the RNA polymerase-recognized sequence in Pω is essential for its centromeric function.
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Affiliation(s)
- Michał Dmowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Izabela Kern-Zdanowicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland
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47
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Dame RT, Tark-Dame M. Bacterial chromatin: converging views at different scales. Curr Opin Cell Biol 2016; 40:60-65. [PMID: 26942688 DOI: 10.1016/j.ceb.2016.02.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/04/2016] [Accepted: 02/14/2016] [Indexed: 01/13/2023]
Abstract
Bacterial genomes are functionally organized and compactly folded into a structure referred to as bacterial chromatin or the nucleoid. An important role in genome folding is attributed to Nucleoid-Associated Proteins, also referred to as bacterial chromatin proteins. Although a lot of molecular insight in the mechanisms of operation of these proteins has been generated in the test tube, knowledge on genome organization in the cellular context is still lagging behind severely. Here, we discuss important advances in the understanding of three-dimensional genome organization due to the application of Chromosome Conformation Capture and super-resolution microscopy techniques. We focus on bacterial chromatin proteins whose proposed role in genome organization is supported by these approaches. Moreover, we discuss recent insights into the interrelationship between genome organization and genome activity/stability in bacteria.
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Affiliation(s)
- Remus T Dame
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Leiden, The Netherlands.
| | - Mariliis Tark-Dame
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
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48
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Directed and persistent movement arises from mechanochemistry of the ParA/ParB system. Proc Natl Acad Sci U S A 2015; 112:E7055-64. [PMID: 26647183 DOI: 10.1073/pnas.1505147112] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos-an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria.
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49
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Wang X, Le TBK, Lajoie BR, Dekker J, Laub MT, Rudner DZ. Condensin promotes the juxtaposition of DNA flanking its loading site in Bacillus subtilis. Genes Dev 2015; 29:1661-75. [PMID: 26253537 PMCID: PMC4536313 DOI: 10.1101/gad.265876.115] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
SMC condensin complexes play a central role in compacting and resolving replicated chromosomes in virtually all organisms, yet how they accomplish this remains elusive. In Bacillus subtilis, condensin is loaded at centromeric parS sites, where it encircles DNA and individualizes newly replicated origins. Using chromosome conformation capture and cytological assays, we show that condensin recruitment to origin-proximal parS sites is required for the juxtaposition of the two chromosome arms. Recruitment to ectopic parS sites promotes alignment of large tracks of DNA flanking these sites. Importantly, insertion of parS sites on opposing arms indicates that these "zip-up" interactions only occur between adjacent DNA segments. Collectively, our data suggest that condensin resolves replicated origins by promoting the juxtaposition of DNA flanking parS sites, drawing sister origins in on themselves and away from each other. These results are consistent with a model in which condensin encircles the DNA flanking its loading site and then slides down, tethering the two arms together. Lengthwise condensation via loop extrusion could provide a generalizable mechanism by which condensin complexes act dynamically to individualize origins in B. subtilis and, when loaded along eukaryotic chromosomes, resolve them during mitosis.
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Affiliation(s)
- Xindan Wang
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Tung B K Le
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Bryan R Lajoie
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Job Dekker
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Michael T Laub
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - David Z Rudner
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
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50
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Sanchez A, Cattoni D, Walter JC, Rech J, Parmeggiani A, Nollmann M, Bouet JY. Stochastic Self-Assembly of ParB Proteins Builds the Bacterial DNA Segregation Apparatus. Cell Syst 2015; 1:163-73. [DOI: 10.1016/j.cels.2015.07.013] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/15/2015] [Accepted: 07/30/2015] [Indexed: 11/25/2022]
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