1
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Wald J, Marlovits TC. Holliday junction branch migration driven by AAA+ ATPase motors. Curr Opin Struct Biol 2023; 82:102650. [PMID: 37604043 DOI: 10.1016/j.sbi.2023.102650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/09/2023] [Accepted: 06/11/2023] [Indexed: 08/23/2023]
Abstract
Holliday junctions are key intermediate DNA structures during genetic recombination. One of the first Holliday junction-processing protein complexes to be discovered was the well conserved RuvAB branch migration complex present in bacteria that mediates an ATP-dependent movement of the Holliday junction (branch migration). Although the RuvAB complex served as a paradigm for the processing of the Holliday junction, due to technical limitations the detailed structure and underlying mechanism of the RuvAB branch migration complex has until now remained unclear. Recently, structures of a reconstituted RuvAB complex actively-processing a Holliday junction were resolved using time-resolved cryo-electron microscopy. These structures showed distinct conformational states at different stages of the migration process. These structures made it possible to propose an integrated model for RuvAB Holliday junction branch migration. Furthermore, they revealed unexpected insights into the highly coordinated and regulated mechanisms of the nucleotide cycle powering substrate translocation in the hexameric AAA+ RuvB ATPase. Here, we review these latest advances and describe areas for future research.
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Affiliation(s)
- Jiri Wald
- Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany; Institute of Structural and Systems Biology, University Medical Center Hamburg-Eppendorf, Notkestraße 85, 22607 Hamburg, Germany; Deutsches Elektronen Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Thomas C Marlovits
- Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany; Institute of Structural and Systems Biology, University Medical Center Hamburg-Eppendorf, Notkestraße 85, 22607 Hamburg, Germany; Deutsches Elektronen Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany.
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2
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Zhang X, Zhou Z, Dai L, Chao Y, Liu Z, Huang M, Qu Q, Lin Z. Cryo-EM structure of the RuvAB-Holliday junction intermediate complex from Pseudomonas aeruginosa. FRONTIERS IN PLANT SCIENCE 2023; 14:1139106. [PMID: 37025142 PMCID: PMC10071043 DOI: 10.3389/fpls.2023.1139106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/27/2023] [Indexed: 06/19/2023]
Abstract
Holliday junction (HJ) is a four-way structured DNA intermediate in homologous recombination. In bacteria, the HJ-specific binding protein RuvA and the motor protein RuvB together form the RuvAB complex to catalyze HJ branch migration. Pseudomonas aeruginosa (P. aeruginosa, Pa) is a ubiquitous opportunistic bacterial pathogen that can cause serious infection in a variety of host species, including vertebrate animals, insects and plants. Here, we describe the cryo-Electron Microscopy (cryo-EM) structure of the RuvAB-HJ intermediate complex from P. aeruginosa. The structure shows that two RuvA tetramers sandwich HJ at the junction center and disrupt base pairs at the branch points of RuvB-free HJ arms. Eight RuvB subunits are recruited by the RuvA octameric core and form two open-rings to encircle two opposite HJ arms. Each RuvB subunit individually binds a RuvA domain III. The four RuvB subunits within the ring display distinct subdomain conformations, and two of them engage the central DNA duplex at both strands with their C-terminal β-hairpins. Together with the biochemical analyses, our structure implicates a potential mechanism of RuvB motor assembly onto HJ DNA.
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Affiliation(s)
- Xu Zhang
- College of Chemistry, Fuzhou University, Fuzhou, China
| | - Zixuan Zhou
- Shanghai Stomatological Hospital, Institutes of Biomedical Science, Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Lin Dai
- College of Chemistry, Fuzhou University, Fuzhou, China
| | - Yulin Chao
- Shanghai Stomatological Hospital, Institutes of Biomedical Science, Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Zheng Liu
- Kobilka Institute of Innovative Drug Discovery, School of Medicine, Chinese University of Hong Kong, Shenzhen, China
| | | | - Qianhui Qu
- Shanghai Stomatological Hospital, Institutes of Biomedical Science, Department of Systems Biology for Medicine, Fudan University, Shanghai, China
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, Fuzhou, China
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3
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McQuaid K, Pipier A, Cardin C, Monchaud D. Interactions of small molecules with DNA junctions. Nucleic Acids Res 2022; 50:12636-12656. [PMID: 36382400 PMCID: PMC9825177 DOI: 10.1093/nar/gkac1043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/13/2022] [Accepted: 10/23/2022] [Indexed: 11/17/2022] Open
Abstract
The four natural DNA bases (A, T, G and C) associate in base pairs (A=T and G≡C), allowing the attached DNA strands to assemble into the canonical double helix of DNA (or duplex-DNA, also known as B-DNA). The intrinsic supramolecular properties of nucleobases make other associations possible (such as base triplets or quartets), which thus translates into a diversity of DNA structures beyond B-DNA. To date, the alphabet of DNA structures is ripe with approximately 20 letters (from A- to Z-DNA); however, only a few of them are being considered as key players in cell biology and, by extension, valuable targets for chemical biology intervention. In the present review, we summarise what is known about alternative DNA structures (what are they? When, where and how do they fold?) and proceed to discuss further about those considered nowadays as valuable therapeutic targets. We discuss in more detail the molecular tools (ligands) that have been recently developed to target these structures, particularly the three- and four-way DNA junctions, in order to intervene in the biological processes where they are involved. This new and stimulating chemical biology playground allows for devising innovative strategies to fight against genetic diseases.
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Affiliation(s)
- Kane T McQuaid
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, UK
| | - Angélique Pipier
- Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB), CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Christine J Cardin
- Correspondence may also be addressed to Christine J. Cardin. Tel: +44 118 378 8215;
| | - David Monchaud
- To whom correspondence should be addressed. Tel: +33 380 399 043;
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4
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Han Z, McAlpine SR, Chapman R. Delivering hydrophilic peptide inhibitors of heat shock protein 70 into cancer cells. Bioorg Chem 2022; 122:105713. [DOI: 10.1016/j.bioorg.2022.105713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 02/24/2022] [Accepted: 02/27/2022] [Indexed: 11/02/2022]
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5
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Gándara C, Torres R, Carrasco B, Ayora S, Alonso JC. DisA Restrains the Processing and Cleavage of Reversed Replication Forks by the RuvAB-RecU Resolvasome. Int J Mol Sci 2021; 22:11323. [PMID: 34768753 PMCID: PMC8583203 DOI: 10.3390/ijms222111323] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/04/2021] [Accepted: 10/16/2021] [Indexed: 11/17/2022] Open
Abstract
DNA lesions that impede fork progression cause replisome stalling and threaten genome stability. Bacillus subtilis RecA, at a lesion-containing gap, interacts with and facilitates DisA pausing at these branched intermediates. Paused DisA suppresses its synthesis of the essential c-di-AMP messenger. The RuvAB-RecU resolvasome branch migrates and resolves formed Holliday junctions (HJ). We show that DisA prevents DNA degradation. DisA, which interacts with RuvB, binds branched structures, and reduces the RuvAB DNA-dependent ATPase activity. DisA pre-bound to HJ DNA limits RuvAB and RecU activities, but such inhibition does not occur if the RuvAB- or RecU-HJ DNA complexes are pre-formed. RuvAB or RecU pre-bound to HJ DNA strongly inhibits DisA-mediated synthesis of c-di-AMP, and indirectly blocks cell proliferation. We propose that DisA limits RuvAB-mediated fork remodeling and RecU-mediated HJ cleavage to provide time for damage removal and replication restart in order to preserve genome integrity.
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Affiliation(s)
| | | | | | - Silvia Ayora
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin St, 28049 Madrid, Spain; (C.G.); (R.T.); (B.C.)
| | - Juan C. Alonso
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin St, 28049 Madrid, Spain; (C.G.); (R.T.); (B.C.)
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6
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Devaraj A, Novotny LA, Robledo-Avila FH, Buzzo JR, Mashburn-Warren L, Jurcisek JA, Tjokro NO, Partida-Sanchez S, Bakaletz LO, Goodman SD. The extracellular innate-immune effector HMGB1 limits pathogenic bacterial biofilm proliferation. J Clin Invest 2021; 131:e140527. [PMID: 34396989 DOI: 10.1172/jci140527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
Herein, we describe an extracellular function of the vertebrate high-mobility group box 1 protein (HMGB1) in the proliferation of bacterial biofilms. Within host cells, HMGB1 functions as a DNA architectural protein, similar to the ubiquitous DNABII family of bacterial proteins; despite that, these proteins share no amino acid sequence identity. Extracellularly, HMGB1 induces a proinflammatory immune response, whereas the DNABII proteins stabilize the extracellular DNA-dependent matrix that maintains bacterial biofilms. We showed that when both proteins converged on extracellular DNA within bacterial biofilms, HMGB1, unlike the DNABII proteins, disrupted biofilms both in vitro (including the high-priority ESKAPEE pathogens) and in vivo in 2 distinct animal models, albeit with induction of a strong inflammatory response that we attenuated by a single engineered amino acid change. We propose a model where extracellular HMGB1 balances the degree of induced inflammation and biofilm containment without excessive release of biofilm-resident bacteria.
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Affiliation(s)
- Aishwarya Devaraj
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Laura A Novotny
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Frank H Robledo-Avila
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - John R Buzzo
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Lauren Mashburn-Warren
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Joseph A Jurcisek
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Natalia O Tjokro
- Division of Periodontology, Diagnostic Sciences, and Dental Hygiene, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA
| | - Santiago Partida-Sanchez
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Steven D Goodman
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
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7
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Bianco PR, Lu Y. Single-molecule insight into stalled replication fork rescue in Escherichia coli. Nucleic Acids Res 2021; 49:4220-4238. [PMID: 33744948 PMCID: PMC8096234 DOI: 10.1093/nar/gkab142] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/15/2021] [Accepted: 02/22/2021] [Indexed: 01/05/2023] Open
Abstract
DNA replication forks stall at least once per cell cycle in Escherichia coli. DNA replication must be restarted if the cell is to survive. Restart is a multi-step process requiring the sequential action of several proteins whose actions are dictated by the nature of the impediment to fork progression. When fork progress is impeded, the sequential actions of SSB, RecG and the RuvABC complex are required for rescue. In contrast, when a template discontinuity results in the forked DNA breaking apart, the actions of the RecBCD pathway enzymes are required to resurrect the fork so that replication can resume. In this review, we focus primarily on the significant insight gained from single-molecule studies of individual proteins, protein complexes, and also, partially reconstituted regression and RecBCD pathways. This insight is related to the bulk-phase biochemical data to provide a comprehensive review of each protein or protein complex as it relates to stalled DNA replication fork rescue.
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Affiliation(s)
- Piero R Bianco
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA
| | - Yue Lu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA
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8
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Kraithong T, Hartley S, Jeruzalmi D, Pakotiprapha D. A Peek Inside the Machines of Bacterial Nucleotide Excision Repair. Int J Mol Sci 2021; 22:ijms22020952. [PMID: 33477956 PMCID: PMC7835731 DOI: 10.3390/ijms22020952] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/13/2022] Open
Abstract
Double stranded DNA (dsDNA), the repository of genetic information in bacteria, archaea and eukaryotes, exhibits a surprising instability in the intracellular environment; this fragility is exacerbated by exogenous agents, such as ultraviolet radiation. To protect themselves against the severe consequences of DNA damage, cells have evolved at least six distinct DNA repair pathways. Here, we review recent key findings of studies aimed at understanding one of these pathways: bacterial nucleotide excision repair (NER). This pathway operates in two modes: a global genome repair (GGR) pathway and a pathway that closely interfaces with transcription by RNA polymerase called transcription-coupled repair (TCR). Below, we discuss the architecture of key proteins in bacterial NER and recent biochemical, structural and single-molecule studies that shed light on the lesion recognition steps of both the GGR and the TCR sub-pathways. Although a great deal has been learned about both of these sub-pathways, several important questions, including damage discrimination, roles of ATP and the orchestration of protein binding and conformation switching, remain to be addressed.
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Affiliation(s)
- Thanyalak Kraithong
- Doctor of Philosophy Program in Biochemistry (International Program), Faculty of Science, Mahidol University, Bangkok 10400, Thailand;
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Silas Hartley
- Department of Chemistry and Biochemistry, City College of New York, New York, NY 10031, USA;
- Doctor of Philosophy Programs in Biochemistry, Biology and Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - David Jeruzalmi
- Department of Chemistry and Biochemistry, City College of New York, New York, NY 10031, USA;
- Doctor of Philosophy Programs in Biochemistry, Biology and Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
- Correspondence: (D.J.); (D.P.)
| | - Danaya Pakotiprapha
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (D.J.); (D.P.)
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9
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Homologous Recombination under the Single-Molecule Fluorescence Microscope. Int J Mol Sci 2019; 20:ijms20236102. [PMID: 31816946 PMCID: PMC6929127 DOI: 10.3390/ijms20236102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/26/2019] [Accepted: 11/30/2019] [Indexed: 11/16/2022] Open
Abstract
Homologous recombination (HR) is a complex biological process and is central to meiosis and for repair of DNA double-strand breaks. Although the HR process has been the subject of intensive study for more than three decades, the complex protein–protein and protein–DNA interactions during HR present a significant challenge for determining the molecular mechanism(s) of the process. This knowledge gap is largely because of the dynamic interactions between HR proteins and DNA which is difficult to capture by routine biochemical or structural biology methods. In recent years, single-molecule fluorescence microscopy has been a popular method in the field of HR to visualize these complex and dynamic interactions at high spatiotemporal resolution, revealing mechanistic insights of the process. In this review, we describe recent efforts that employ single-molecule fluorescence microscopy to investigate protein–protein and protein–DNA interactions operating on three key DNA-substrates: single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), and four-way DNA called Holliday junction (HJ). We also outline the technological advances and several key insights revealed by these studies in terms of protein assembly on these DNA substrates and highlight the foreseeable promise of single-molecule fluorescence microscopy in advancing our understanding of homologous recombination.
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10
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The extracellular DNA lattice of bacterial biofilms is structurally related to Holliday junction recombination intermediates. Proc Natl Acad Sci U S A 2019; 116:25068-25077. [PMID: 31767757 DOI: 10.1073/pnas.1909017116] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Extracellular DNA (eDNA) is a critical component of the extracellular matrix of bacterial biofilms that protects the resident bacteria from environmental hazards, which includes imparting significantly greater resistance to antibiotics and host immune effectors. eDNA is organized into a lattice-like structure, stabilized by the DNABII family of proteins, known to have high affinity and specificity for Holliday junctions (HJs). Accordingly, we demonstrated that the branched eDNA structures present within the biofilms formed by NTHI in the middle ear of the chinchilla in an experimental otitis media model, and in sputum samples recovered from cystic fibrosis patients that contain multiple mixed bacterial species, possess an HJ-like configuration. Next, we showed that the prototypic Escherichia coli HJ-specific DNA-binding protein RuvA could be functionally exchanged for DNABII proteins in the stabilization of biofilms formed by 3 diverse human pathogens, uropathogenic E. coli, nontypeable Haemophilus influenzae, and Staphylococcus epidermidis Importantly, while replacement of DNABII proteins within the NTHI biofilm matrix with RuvA was shown to retain similar mechanical properties when compared to the control NTHI biofilm structure, we also demonstrated that biofilm eDNA matrices stabilized by RuvA could be subsequently undermined upon addition of the HJ resolvase complex, RuvABC, which resulted in significant biofilm disruption. Collectively, our data suggested that nature has recapitulated a functional equivalent of the HJ recombination intermediate to maintain the structural integrity of bacterial biofilms.
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11
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Structure of the Holliday junction: applications beyond recombination. Biochem Soc Trans 2017; 45:1149-1158. [PMID: 28842529 DOI: 10.1042/bst20170048] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/20/2017] [Accepted: 07/24/2017] [Indexed: 12/24/2022]
Abstract
The Holliday junction (HJ) is an essential element in recombination and related mechanisms. The structure of this four-stranded DNA assembly, which is now well-defined alone and in complex with proteins, has led to its applications in areas well outside of molecular recombination, including nanotechnology and biophysics. This minireview explores some interesting recent research on the HJ, as it has been adapted to design regular two- or three-dimensional lattices for crystal engineering, and more complex systems through DNA origami. In addition, the sequence dependence of the structure is discussed in terms how it can be applied to characterize the geometries and energies of various noncovalent interactions, including halogen bonds in oxidatively damaged (halogenated) bases and hydrogen bonds associated with the epigenetic 5-hydroxylmethylcytosine base.
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12
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Simmons CR, Zhang F, MacCulloch T, Fahmi N, Stephanopoulos N, Liu Y, Seeman NC, Yan H. Tuning the Cavity Size and Chirality of Self-Assembling 3D DNA Crystals. J Am Chem Soc 2017; 139:11254-11260. [PMID: 28731332 DOI: 10.1021/jacs.7b06485] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The foundational goal of structural DNA nanotechnology-the field that uses oligonucleotides as a molecular building block for the programmable self-assembly of nanostructured systems-was to use DNA to construct three-dimensional (3D) lattices for solving macromolecular structures. The programmable nature of DNA makes it an ideal system for rationally constructing self-assembled crystals and immobilizing guest molecules in a repeating 3D array through their specific stereospatial interactions with the scaffold. In this work, we have extended a previously described motif (4 × 5) by expanding the structure to a system that links four double-helical layers; we use a central weaving oligonucleotide containing a sequence of four six-base repeats (4 × 6), forming a matrix of layers that are organized and dictated by a series of Holliday junctions. In addition, we have assembled mirror image crystals (l-DNA) with the identical sequence that are completely resistant to nucleases. Bromine and selenium derivatives were obtained for the l- and d-DNA forms, respectively, allowing phase determination for both forms and solution of the resulting structures to 3.0 and 3.05 Å resolution. Both right- and left-handed forms crystallized in the trigonal space groups with mirror image 3-fold helical screw axes P32 and P31 for each motif, respectively. The structures reveal a highly organized array of discrete and well-defined cavities that are suitable for hosting guest molecules and allow us to dictate a priori the assembly of guest-DNA conjugates with a specified crystalline hand.
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Affiliation(s)
| | | | | | | | | | | | - Nadrian C Seeman
- Department of Chemistry, New York University , New York, New York 10003, United States
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13
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Zhai B, DuPrez K, Doukov TI, Li H, Huang M, Shang G, Ni J, Gu L, Shen Y, Fan L. Structure and Function of a Novel ATPase that Interacts with Holliday Junction Resolvase Hjc and Promotes Branch Migration. J Mol Biol 2017; 429:1009-1029. [PMID: 28238763 PMCID: PMC5565510 DOI: 10.1016/j.jmb.2017.02.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 01/25/2017] [Accepted: 02/19/2017] [Indexed: 11/15/2022]
Abstract
Holliday junction (HJ) is a hallmark intermediate in DNA recombination and must be processed by dissolution (for double HJ) or resolution to ensure genome stability. Although HJ resolvases have been identified in all domains of life, there is a long-standing effort to search in prokaryotes and eukarya for proteins promoting HJ migration. Here, we report the structural and functional characterization of a novel ATPase, Sulfolobus islandicusPilT N-terminal-domain-containing ATPase (SisPINA), encoded by the gene adjacent to the resolvase Hjc coding gene. PINA is conserved in archaea and vital for S. islandicus viability. Purified SisPINA forms hexameric rings in the crystalline state and in solution, similar to the HJ migration helicase RuvB in Gram-negative bacteria. Structural analysis suggests that ATP binding and hydrolysis cause conformational changes in SisPINA to drive branch migration. Further studies reveal that SisPINA interacts with SisHjc and coordinates HJ migration and cleavage.
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Affiliation(s)
- Binyuan Zhai
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Road, Jinan 250100, PR China
| | - Kevin DuPrez
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
| | - Tzanko I Doukov
- Macromolecular Crystallography Group, Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94309, USA
| | - Huan Li
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Road, Jinan 250100, PR China
| | - Mengting Huang
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Road, Jinan 250100, PR China
| | - Guijun Shang
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Road, Jinan 250100, PR China
| | - Jinfeng Ni
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Road, Jinan 250100, PR China
| | - Lichuan Gu
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Road, Jinan 250100, PR China
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Road, Jinan 250100, PR China.
| | - Li Fan
- Department of Biochemistry, University of California, Riverside, CA 92521, USA.
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14
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Cannon B, Kachroo AH, Jarmoskaite I, Jayaram M, Russell R. Hexapeptides that inhibit processing of branched DNA structures induce a dynamic ensemble of Holliday junction conformations. J Biol Chem 2015; 290:22734-46. [PMID: 26209636 PMCID: PMC4566245 DOI: 10.1074/jbc.m115.663930] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/23/2015] [Indexed: 11/06/2022] Open
Abstract
Holliday junctions are critical intermediates in DNA recombination, repair, and restart of blocked replication. Hexapeptides have been identified that bind to junctions and inhibit various junction-processing enzymes, and these peptides confer anti-microbial and anti-tumor properties. Earlier studies suggested that inhibition results from stabilization of peptide-bound Holliday junctions in the square planar conformation. Here, we use single molecule fluorescence resonance energy transfer (smFRET) and two model junctions, which are AT- or GC-rich at the branch points, to show that binding of the peptide KWWCRW induces a dynamic ensemble of junction conformations that differs from both the square planar and stacked X conformations. The specific features of the conformational distributions differ for the two peptide-bound junctions, but both junctions display greatly decreased Mg(2+) dependence and increased conformational fluctuations. The smFRET results, complemented by gel mobility shift and small angle x-ray scattering analyses, reveal structural effects of peptides and highlight the sensitivity of smFRET for analyzing complex mixtures of DNA structures. The peptide-induced conformational dynamics suggest multiple stacking arrangements of aromatic amino acids with the nucleobases at the junction core. This conformational heterogeneity may inhibit DNA processing by increasing the population of inactive junction conformations, thereby preventing the binding of processing enzymes and/or resulting in their premature dissociation.
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Affiliation(s)
- Brian Cannon
- From the Department of Molecular Biosciences and the Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Aashiq H Kachroo
- From the Department of Molecular Biosciences and the Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Inga Jarmoskaite
- From the Department of Molecular Biosciences and the Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Makkuni Jayaram
- From the Department of Molecular Biosciences and the Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Rick Russell
- From the Department of Molecular Biosciences and the Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
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15
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Yadav RK, Yadava U. Molecular dynamics simulation of hydrated d(CGGGTACCCG)4as a four-way DNA Holliday junction and comparison with the crystallographic structure. MOLECULAR SIMULATION 2015. [DOI: 10.1080/08927022.2015.1007052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Abstract
Four-way DNA intermediates, called Holliday junctions (HJs), can form during meiotic and mitotic recombination, and their removal is crucial for chromosome segregation. A group of ubiquitous and highly specialized structure-selective endonucleases catalyze the cleavage of HJs into two disconnected DNA duplexes in a reaction called HJ resolution. These enzymes, called HJ resolvases, have been identified in bacteria and their bacteriophages, archaea, and eukaryotes. In this review, we discuss fundamental aspects of the HJ structure and their interaction with junction-resolving enzymes. This is followed by a brief discussion of the eubacterial RuvABC enzymes, which provide the paradigm for HJ resolvases in other organisms. Finally, we review the biochemical and structural properties of some well-characterized resolvases from archaea, bacteriophage, and eukaryotes.
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Affiliation(s)
- Haley D M Wyatt
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, United Kingdom
| | - Stephen C West
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, United Kingdom
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17
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Mawer JSP, Leach DRF. Branch migration prevents DNA loss during double-strand break repair. PLoS Genet 2014; 10:e1004485. [PMID: 25102287 PMCID: PMC4125073 DOI: 10.1371/journal.pgen.1004485] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 05/18/2014] [Indexed: 11/19/2022] Open
Abstract
The repair of DNA double-strand breaks must be accurate to avoid genomic rearrangements that can lead to cell death and disease. This can be accomplished by promoting homologous recombination between correctly aligned sister chromosomes. Here, using a unique system for generating a site-specific DNA double-strand break in one copy of two replicating Escherichia coli sister chromosomes, we analyse the intermediates of sister-sister double-strand break repair. Using two-dimensional agarose gel electrophoresis, we show that when double-strand breaks are formed in the absence of RuvAB, 4-way DNA (Holliday) junctions are accumulated in a RecG-dependent manner, arguing against the long-standing view that the redundancy of RuvAB and RecG is in the resolution of Holliday junctions. Using pulsed-field gel electrophoresis, we explain the redundancy by showing that branch migration catalysed by RuvAB and RecG is required for stabilising the intermediates of repair as, when branch migration cannot take place, repair is aborted and DNA is lost at the break locus. We demonstrate that in the repair of correctly aligned sister chromosomes, an unstable early intermediate is stabilised by branch migration. This reliance on branch migration may have evolved to help promote recombination between correctly aligned sister chromosomes to prevent genomic rearrangements. Genetic recombination is critically important for the repair of DNA double-strand breaks and is the only repair mechanism available to the bacterium Escherichia coli. Repair requires that the appropriate location on an unbroken sister chromosome is recognised as a repair template, and this can be accomplished by a system that detects the presence of extensive DNA sequence identity. We show here that the two known branch migration activities of the cell, RuvAB and RecG, provide alternative mechanisms for stabilising early recombination intermediates. In their absence, broken DNA is extensively degraded at the site of the break consistent with abortion of recombination. It has previously been proposed that RuvABC and RecG can substitute for each other in the resolution of four-way Holliday junctions, whereas we show that they play a synergistic role in the formations of these junctions. Our results demonstrate that branch migration provides a mechanism capable of stabilising recombination intermediates when extensive DNA sequence homology is available, a reaction that may contribute to ensuring that repair occurs at an appropriate location on a sister chromosome.
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Affiliation(s)
- Julia S. P. Mawer
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Kings Buildings, Edinburgh, United Kingdom
| | - David R. F. Leach
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Kings Buildings, Edinburgh, United Kingdom
- * E-mail:
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18
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Cañas C, Suzuki Y, Marchisone C, Carrasco B, Freire-Benéitez V, Takeyasu K, Alonso JC, Ayora S. Interaction of branch migration translocases with the Holliday junction-resolving enzyme and their implications in Holliday junction resolution. J Biol Chem 2014; 289:17634-46. [PMID: 24770420 DOI: 10.1074/jbc.m114.552794] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Double-strand break repair involves the formation of Holliday junction (HJ) structures that need to be resolved to promote correct replication and chromosomal segregation. The molecular mechanisms of HJ branch migration and/or resolution are poorly characterized in Firmicutes. Genetic evidence suggested that the absence of the RuvAB branch migration translocase and the RecU HJ resolvase is synthetically lethal in Bacillus subtilis, whereas a recU recG mutant was viable. In vitro RecU, which is restricted to bacteria of the Firmicutes phylum, binds HJs with high affinity. In this work we found that RecU does not bind simultaneously with RecG to a HJ. RuvB by interacting with RecU bound to the central region of HJ DNA, loses its nonspecific association with DNA, and re-localizes with RecU to form a ternary complex. RecU cannot stimulate the ATPase or branch migration activity of RuvB. The presence of RuvB·ATPγS greatly stimulates RecU-mediated HJ resolution, but the addition of ATP or RuvA abolishes this stimulatory effect. A RecU·HJ·RuvAB complex might be formed. RecU does not increase the RuvAB activities but slightly inhibits them.
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Affiliation(s)
- Cristina Cañas
- From the Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Departamento de Biotecnología Microbiana, 28049 Madrid, Spain and
| | - Yuki Suzuki
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Chiara Marchisone
- From the Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Departamento de Biotecnología Microbiana, 28049 Madrid, Spain and
| | - Begoña Carrasco
- From the Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Departamento de Biotecnología Microbiana, 28049 Madrid, Spain and
| | - Verónica Freire-Benéitez
- From the Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Departamento de Biotecnología Microbiana, 28049 Madrid, Spain and
| | - Kunio Takeyasu
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Juan C Alonso
- From the Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Departamento de Biotecnología Microbiana, 28049 Madrid, Spain and
| | - Silvia Ayora
- From the Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Departamento de Biotecnología Microbiana, 28049 Madrid, Spain and
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Abd Wahab S, Choi M, Bianco PR. Characterization of the ATPase activity of RecG and RuvAB proteins on model fork structures reveals insight into stalled DNA replication fork repair. J Biol Chem 2013; 288:26397-409. [PMID: 23893472 DOI: 10.1074/jbc.m113.500223] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RecG and RuvAB are proposed to act at stalled DNA replication forks to facilitate replication restart. To clarify the roles of these proteins in fork regression, we used a coupled spectrophotometric ATPase assay to determine how these helicases act on two groups of model fork substrates: the first group mimics nascent stalled forks, whereas the second mimics regressed fork structures. The results show that RecG is active on the substrates in group 1, whereas these are poor substrates for RuvAB. In addition, in the presence of group 1 forks, the single-stranded DNA-binding protein (SSB) enhances the activity of RecG and enables it to compete with excess RuvA. In contrast, SSB inhibits the activity of RuvAB on these substrates. Results also show that the preferred regressed fork substrate for RuvAB is a Holliday junction, not a forked DNA. The active form of the enzyme on the Holliday junction contains a single RuvA tetramer. In contrast, although the enzyme is active on a regressed fork structure, RuvB loading by a single RuvA tetramer is impaired, and full activity requires the cooperative binding of two forked DNA substrate molecules. Collectively, the data support a model where RecG is responsible for stalled DNA replication fork regression. SSB ensures that if the nascent fork has single-stranded DNA character RuvAB is inhibited, whereas the activity of RecG is preferentially enhanced. Only once the fork has been regressed and the DNA is relaxed can RuvAB bind to a RecG-extruded Holliday junction.
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20
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Structure and Mechanisms of SF1 DNA Helicases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 767:17-46. [PMID: 23161005 DOI: 10.1007/978-1-4614-5037-5_2] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Superfamily I is a large and diverse group of monomeric and dimeric helicases defined by a set of conserved sequence motifs. Members of this class are involved in essential processes in both DNA and RNA metabolism in all organisms. In addition to conserved amino acid sequences, they also share a common structure containing two RecA-like motifs involved in ATP binding and hydrolysis and nucleic acid binding and unwinding. Unwinding is facilitated by a "pin" structure which serves to split the incoming duplex. This activity has been measured using both ensemble and single-molecule conditions. SF1 helicase activity is modulated through interactions with other proteins.
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Abstract
Homologous recombination is an ubiquitous process that shapes genomes and repairs DNA damage. The reaction is classically divided into three phases: presynaptic, synaptic, and postsynaptic. In Escherichia coli, the presynaptic phase involves either RecBCD or RecFOR proteins, which act on DNA double-stranded ends and DNA single-stranded gaps, respectively; the central synaptic steps are catalyzed by the ubiquitous DNA-binding protein RecA; and the postsynaptic phase involves either RuvABC or RecG proteins, which catalyze branch-migration and, in the case of RuvABC, the cleavage of Holliday junctions. Here, we review the biochemical properties of these molecular machines and analyze how, in light of these properties, the phenotypes of null mutants allow us to define their biological function(s). The consequences of point mutations on the biochemical properties of recombination enzymes and on cell phenotypes help refine the molecular mechanisms of action and the biological roles of recombination proteins. Given the high level of conservation of key proteins like RecA and the conservation of the principles of action of all recombination proteins, the deep knowledge acquired during decades of studies of homologous recombination in bacteria is the foundation of our present understanding of the processes that govern genome stability and evolution in all living organisms.
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22
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Sluijter M, Estevão S, Hoogenboezem T, Hartwig NG, van Rossum AMC, Vink C. The RuvA homologues from Mycoplasma genitalium and Mycoplasma pneumoniae exhibit unique functional characteristics. PLoS One 2012; 7:e38301. [PMID: 22666500 PMCID: PMC3364216 DOI: 10.1371/journal.pone.0038301] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 05/03/2012] [Indexed: 11/18/2022] Open
Abstract
The DNA recombination and repair machineries of Mycoplasma genitalium and Mycoplasma pneumoniae differ considerably from those of gram-positive and gram-negative bacteria. Most notably, M. pneumoniae is unable to express a functional RecU Holliday junction (HJ) resolvase. In addition, the RuvB homologues from both M. pneumoniae and M. genitalium only exhibit DNA helicase activity but not HJ branch migration activity in vitro. To identify a putative role of the RuvA homologues of these mycoplasmas in DNA recombination, both proteins (RuvAMpn and RuvAMge, respectively) were studied for their ability to bind DNA and to interact with RuvB and RecU. In spite of a high level of sequence conservation between RuvAMpn and RuvAMge (68.8% identity), substantial differences were found between these proteins in their activities. First, RuvAMge was found to preferentially bind to HJs, whereas RuvAMpn displayed similar affinities for both HJs and single-stranded DNA. Second, while RuvAMpn is able to form two distinct complexes with HJs, RuvAMge only produced a single HJ complex. Third, RuvAMge stimulated the DNA helicase and ATPase activities of RuvBMge, whereas RuvAMpn did not augment RuvB activity. Finally, while both RuvAMge and RecUMge efficiently bind to HJs, they did not compete with each other for HJ binding, but formed stable complexes with HJs over a wide protein concentration range. This interaction, however, resulted in inhibition of the HJ resolution activity of RecUMge.
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Affiliation(s)
- Marcel Sluijter
- Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Silvia Estevão
- Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Theo Hoogenboezem
- Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Nico G. Hartwig
- Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Annemarie M. C. van Rossum
- Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Cornelis Vink
- Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
- * E-mail:
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23
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Khanduja JS, Muniyappa K. Functional analysis of DNA replication fork reversal catalyzed by Mycobacterium tuberculosis RuvAB proteins. J Biol Chem 2012; 287:1345-60. [PMID: 22094465 PMCID: PMC3256873 DOI: 10.1074/jbc.m111.304741] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/14/2011] [Indexed: 11/06/2022] Open
Abstract
Initially discovered in Escherichia coli, RuvAB proteins are ubiquitous in bacteria and play a dual role as molecular motor proteins responsible for branch migration of the Holliday junction(s) and reversal of stalled replication forks. Despite mounting genetic evidence for a crucial role of RuvA and RuvB proteins in reversal of stalled replication forks, the mechanistic aspects of this process are still not fully understood. Here, we elucidate the ability of Mycobacterium tuberculosis RuvAB (MtRuvAB) complex to catalyze the reversal of replication forks using a range of DNA replication fork substrates. Our studies show that MtRuvAB, unlike E. coli RuvAB, is able to drive replication fork reversal via the formation of Holliday junction intermediates, suggesting that RuvAB-catalyzed fork reversal involves concerted unwinding and annealing of nascent leading and lagging strands. We also demonstrate the reversal of replication forks carrying hemi-replicated DNA, indicating that MtRuvAB complex-catalyzed fork reversal is independent of symmetry at the fork junction. The fork reversal reaction catalyzed by MtRuvAB is coupled to ATP hydrolysis, is processive, and culminates in the formation of an extended reverse DNA arm. Notably, we found that sequence heterology failed to impede the fork reversal activity of MtRuvAB. We discuss the implications of these results in the context of recognition and processing of varied types of replication fork structures by RuvAB proteins.
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Affiliation(s)
- Jasbeer Singh Khanduja
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - K. Muniyappa
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
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24
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Amunugama R, Fishel R. Homologous Recombination in Eukaryotes. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 110:155-206. [DOI: 10.1016/b978-0-12-387665-2.00007-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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25
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Bradley AS, Baharoglu Z, Niewiarowski A, Michel B, Tsaneva IR. Formation of a stable RuvA protein double tetramer is required for efficient branch migration in vitro and for replication fork reversal in vivo. J Biol Chem 2011; 286:22372-83. [PMID: 21531731 DOI: 10.1074/jbc.m111.233908] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In bacteria, RuvABC is required for the resolution of Holliday junctions (HJ) made during homologous recombination. The RuvAB complex catalyzes HJ branch migration and replication fork reversal (RFR). During RFR, a stalled fork is reversed to form a HJ adjacent to a DNA double strand end, a reaction that requires RuvAB in certain Escherichia coli replication mutants. The exact structure of active RuvAB complexes remains elusive as it is still unknown whether one or two tetramers of RuvA support RuvB during branch migration and during RFR. We designed an E. coli RuvA mutant, RuvA2(KaP), specifically impaired for RuvA tetramer-tetramer interactions. As expected, the mutant protein is impaired for complex II (two tetramers) formation on HJs, although the binding efficiency of complex I (a single tetramer) is as wild type. We show that although RuvA complex II formation is required for efficient HJ branch migration in vitro, RuvA2(KaP) is fully active for homologous recombination in vivo. RuvA2(KaP) is also deficient at forming complex II on synthetic replication forks, and the binding affinity of RuvA2(KaP) for forks is decreased compared with wild type. Accordingly, RuvA2(KaP) is inefficient at processing forks in vitro and in vivo. These data indicate that RuvA2(KaP) is a separation-of-function mutant, capable of homologous recombination but impaired for RFR. RuvA2(KaP) is defective for stimulation of RuvB activity and stability of HJ·RuvA·RuvB tripartite complexes. This work demonstrates that the need for RuvA tetramer-tetramer interactions for full RuvAB activity in vitro causes specifically an RFR defect in vivo.
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Affiliation(s)
- Alison S Bradley
- Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT, United Kingdom
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26
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Ishida H. Branch migration of Holliday junction in RuvA tetramer complex studied by umbrella sampling simulation using a path-search algorithm. J Comput Chem 2010; 31:2317-29. [PMID: 20575014 DOI: 10.1002/jcc.21525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Branch migration of the Holliday junction takes place at the center of the RuvA tetramer. To elucidate how branch migration occurs, umbrella sampling simulations were performed for complexes of the RuvA tetramer and Holliday junction DNA. Although conventional umbrella sampling simulations set sampling points a priori, the umbrella sampling simulation in this study set the sampling points one by one in order to search for a realistic path of the branch migration during the simulations. Starting from the X-ray structure of the complex, in which the hydrogen bonds between two base-pairs were unformed, the hydrogen bonds between the next base-pairs of the shrinking stems were observed to start to disconnect. At the intermediate stage, three or four of the eight unpaired bases interacted closely with the acidic pins from RuvA. During the final stage, these bases moved away from the pins and formed the hydrogen bonds of the new base-pairs of the growing stems. The free-energy profile along this reaction path showed that the intermediate stage was a meta-stable state between two free-energy barriers of about 10 to 15 kcal/mol. These results imply that the pins play an important role in stabilizing the interactions between the pins and the unpaired base-pairs.
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Affiliation(s)
- Hisashi Ishida
- Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1-7 Umemidai, Kizugawa-shi, Kyoto 619-0215, Japan.
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27
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Abstract
DNA and RNA helicases are organized into six superfamilies of enzymes on the basis of sequence alignments, biochemical data, and available crystal structures. DNA helicases, members of which are found in each of the superfamilies, are an essential group of motor proteins that unwind DNA duplexes into their component single strands in a process that is coupled to the hydrolysis of nucleoside 5'-triphosphates. The purpose of this DNA unwinding is to provide nascent, single-stranded DNA (ssDNA) for the processes of DNA repair, replication, and recombination. Not surprisingly, DNA helicases share common biochemical properties that include the binding of single- and double-stranded DNA, nucleoside 5'-triphosphate binding and hydrolysis, and nucleoside 5'-triphosphate hydrolysis-coupled, polar unwinding of duplex DNA. These enzymes participate in every aspect of DNA metabolism due to the requirement for transient separation of small regions of the duplex genome into its component strands so that replication, recombination, and repair can occur. In Escherichia coli, there are currently twelve DNA helicases that perform a variety of tasks ranging from simple strand separation at the replication fork to more sophisticated processes in DNA repair and genetic recombination. In this chapter, the superfamily classification, role(s) in DNA metabolism, effects of mutations, biochemical analysis, oligomeric nature, and interacting partner proteins of each of the twelve DNA helicases are discussed.
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28
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Vindigni A, Marino F, Gileadi O. Probing the structural basis of RecQ helicase function. Biophys Chem 2010; 149:67-77. [PMID: 20392558 DOI: 10.1016/j.bpc.2010.03.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 03/11/2010] [Accepted: 03/11/2010] [Indexed: 01/10/2023]
Abstract
RecQ helicases are a ubiquitous family of DNA unwinding enzymes required to preserve genome integrity, thus preventing premature aging and cancer formation. The five human representatives of this family play non-redundant roles in the suppression of genome instability using a combination of enzymatic activities that specifically characterize each member of the family. These enzymes are in fact not only able to catalyze the transient opening of DNA duplexes, as any other conventional helicase, but can also promote annealing of complementary strands, branch migration of Holliday junctions and, in some cases, excision of ssDNA tails. Remarkably, the balance between these different activities seems to be regulated by protein oligomerization. This review illustrates the recent progress made in the definition of the structural determinants that control the different enzymatic activities of RecQ helicases and speculates on the possible mechanisms that RecQ proteins might use to promote their multiple functions.
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Affiliation(s)
- Alessandro Vindigni
- International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy.
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29
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McGuinness CD, Nishimura MKY, Keszenman-Pereyra D, Dickinson P, Campbell CJ, Bachmann TT, Ghazal P, Crain J. Detection of single nucleotide polymorphisms using a DNA Holliday junction nanoswitch—a high-throughput fluorescence lifetime assay. ACTA ACUST UNITED AC 2010; 6:386-90. [DOI: 10.1039/b913455g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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The extent of migration of the Holliday junction is a crucial factor for gene conversion in Rhizobium etli. J Bacteriol 2009; 191:4987-95. [PMID: 19502410 DOI: 10.1128/jb.00111-09] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Gene conversion, defined as the nonreciprocal transfer of DNA, is one result of homologous recombination. Three steps in recombination could give rise to gene conversion: (i) DNA synthesis for repair of the degraded segment, (ii) Holliday junction migration, leading to heteroduplex formation, and (iii) repair of mismatches in the heteroduplex. There are at least three proteins (RuvAB, RecG, and RadA) that participate in the second step. Their roles have been studied for homologous recombination, but evidence of their relative role in gene conversion is lacking. In this work, we showed the effect on gene conversion of mutations in ruvB, recG, and radA in Rhizobium etli, either alone or in combination, using a cointegration strategy previously developed in our laboratory. The results indicate that the RuvAB system is highly efficient for gene conversion, since its absence provokes smaller gene conversion segments than those in the wild type as well as a shift in the preferred position of conversion tracts. The RecG system possesses a dual role for gene conversion. Inactivation of recG leads to longer gene conversion tracts than those in the wild type, indicating that its activity may hinder heteroduplex extension. However, under circumstances where it is the only migration activity present (as in the ruvB radA double mutant), conversion segments can still be seen, indicating that RecG can also promote gene conversion. RadA is the least efficient system in R. etli but is still needed for the production of detectable gene conversion tracts.
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31
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Atkinson J, McGlynn P. Replication fork reversal and the maintenance of genome stability. Nucleic Acids Res 2009; 37:3475-92. [PMID: 19406929 PMCID: PMC2699526 DOI: 10.1093/nar/gkp244] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The progress of replication forks is often threatened in vivo, both by DNA damage and by proteins bound to the template. Blocked forks must somehow be restarted, and the original blockage cleared, in order to complete genome duplication, implying that blocked fork processing may be critical for genome stability. One possible pathway that might allow processing and restart of blocked forks, replication fork reversal, involves the unwinding of blocked forks to form four-stranded structures resembling Holliday junctions. This concept has gained increasing popularity recently based on the ability of such processing to explain many genetic observations, the detection of unwound fork structures in vivo and the identification of enzymes that have the capacity to catalyse fork regression in vitro. Here, we discuss the contexts in which fork regression might occur, the factors that may promote such a reaction and the possible roles of replication fork unwinding in normal DNA metabolism.
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Affiliation(s)
- John Atkinson
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
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32
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Prabu JR, Thamotharan S, Khanduja JS, Chandra NR, Muniyappa K, Vijayan M. Crystallographic and modelling studies on Mycobacterium tuberculosis RuvA Additional role of RuvB-binding domain and inter species variability. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:1001-9. [PMID: 19374958 DOI: 10.1016/j.bbapap.2009.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 04/06/2009] [Accepted: 04/06/2009] [Indexed: 11/28/2022]
Abstract
RuvA, along with RuvB, is involved in branch migration of heteroduplex DNA in homologous recombination. The structures of three new crystal forms of RuvA from Mycobacterium tuberculosis (MtRuvA) have been determined. The RuvB-binding domain is cleaved off in one of them. Detailed models of the complexes of octameric RuvA from different species with the Holliday junction have also been constructed. A thorough examination of the structures presented here and those reported earlier brings to light the hitherto unappreciated role of the RuvB-binding domain in determining inter-domain orientation and oligomerization. These structures also permit an exploration of the interspecies variability of structural features such as oligomerization and the conformation of the loop that carries the acidic pin, in terms of amino acid substitutions. These models emphasize the additional role of the RuvB-binding domain in Holliday junction binding. This role along with its role in oligomerization could have important biological implications.
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Affiliation(s)
- J Rajan Prabu
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
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33
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Khanduja JS, Tripathi P, Muniyappa K. Mycobacterium tuberculosis RuvA induces two distinct types of structural distortions between the homologous and heterologous Holliday junctions. Biochemistry 2009; 48:27-40. [PMID: 19072585 DOI: 10.1021/bi8016526] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A central step in the process of homologous genetic recombination is the strand exchange between two homologous DNA molecules, leading to the formation of the Holliday junction intermediate. Several lines of evidence, both in vitro and in vivo, suggest a concerted role for the Escherichia coli RuvABC protein complex in the process of branch migration and the resolution of the Holliday junctions. A number of investigations have examined the role of RuvA protein in branch migration of the Holliday junction in conjunction with its natural cellular partner, RuvB. However, it remains unclear whether the RuvABC protein complex or its individual subunits function differently in the context of DNA repair and homologous recombination. In this study, we have specifically investigated the function of RuvA protein using Holliday junctions containing either homologous or heterologous arms. Our data show that Mycobacterium tuberculosis ruvA complements E. coli DeltaruvA mutants for survival to genotoxic stress caused by different DNA-damaging agents, and the purified RuvA protein binds HJ in preference to any other substrates. Strikingly, our analysis revealed two distinct types of structural distortions caused by M. tuberculosis RuvA between the homologous and heterologous Holliday junctions. We interpret these data as evidence that local distortion of base pairing in the arms of homologous Holliday junctions by RuvA might augment branch migration catalyzed by RuvB. The biological significance of two modes of structural distortion caused by M. tuberculosis RuvA and the implications for its role in DNA repair and homologous recombination are discussed.
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Buss JA, Kimura Y, Bianco PR. RecG interacts directly with SSB: implications for stalled replication fork regression. Nucleic Acids Res 2008; 36:7029-42. [PMID: 18986999 PMCID: PMC2602778 DOI: 10.1093/nar/gkn795] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
RecG and RuvAB are proposed to act at stalled DNA replication forks to facilitate replication restart. To define the roles of these proteins in fork regression, we used a combination of assays to determine whether RecG, RuvAB or both are capable of acting at a stalled fork. The results show that RecG binds to the C-terminus of single-stranded DNA binding protein (SSB) forming a stoichiometric complex of 2 RecG monomers per SSB tetramer. This binding occurs in solution and to SSB protein bound to single stranded DNA (ssDNA). The result of this binding is stabilization of the interaction of RecG with ssDNA. In contrast, RuvAB does not bind to SSB. Side-by-side analysis of the catalytic efficiency of the ATPase activity of each enzyme revealed that (-)scDNA and ssDNA are potent stimulators of the ATPase activity of RecG but not for RuvAB, whereas relaxed circular DNA is a poor cofactor for RecG but an excellent one for RuvAB. Collectively, these data suggest that the timing of repair protein access to the DNA at stalled forks is determined by the nature of the DNA available at the fork. We propose that RecG acts first, with RuvAB acting either after RecG or in a separate pathway following protein-independent fork regression.
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Affiliation(s)
- Jackson A Buss
- Department of Microbiology and Immunology, Center for Single Molecule Biophysics, University at Buffalo, Buffalo, NY 14214, USA
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Karymov MA, Chinnaraj M, Bogdanov A, Srinivasan AR, Zheng G, Olson WK, Lyubchenko YL. Structure, dynamics, and branch migration of a DNA Holliday junction: a single-molecule fluorescence and modeling study. Biophys J 2008; 95:4372-83. [PMID: 18658216 PMCID: PMC2567953 DOI: 10.1529/biophysj.108.135103] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 07/18/2008] [Indexed: 11/18/2022] Open
Abstract
The Holliday junction (HJ) is a central intermediate of various genetic processes, including homologous and site-specific DNA recombination and DNA replication. Elucidating the structure and dynamics of HJs provides the basis for understanding the molecular mechanisms of these genetic processes. Our previous single-molecule fluorescence studies led to a model according to which branch migration is a stepwise process consisting of consecutive migration and folding steps. These data led us to the conclusion that one hop can be more than 1 basepair (bp); moreover, we hypothesized that continuous runs over the entire sequence homology (5 bp) can occur. Direct measurements of the dependence of the fluorescence resonance energy transfer (FRET) value on the donor-acceptor (D-A) distance are required to justify this model and are the major goal of this article. To accomplish this goal, we performed single-molecule FRET experiments with a set of six immobile HJ molecules with varying numbers of bps between fluorescent dyes placed on opposite arms. The designs were made in such a way that the distances between the donor and acceptor were equal to the distances between the dyes formed upon 1-bp migration hops of a HJ having 10-bp homology. Using these designs, we confirmed our previous hypothesis that the migration of the junction can be measured with bp accuracy. Moreover, the FRET values determined for each acceptor-donor separation corresponded very well to the values for the steps on the FRET time trajectories, suggesting that each step corresponds to the migration of the branch at a defined depth. We used the dependence of the FRET value on the D-A distance to measure directly the size for each step on the FRET time trajectories. These data showed that one hop is not necessarily 1 bp. The junction is able to migrate over several bps, detected as one hop and confirming our model. The D-A distances extracted from the FRET properties of the immobile junctions formed the basis for modeling the HJ structures. The composite data fit a partially opened, side-by-side model with adjacent double-helical arms slightly kinked at the four-way junction and the junction as a whole adopting a global X-shaped form that mimics the coaxially stacked-X structure implicated in previous solution studies.
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Affiliation(s)
- Mikhail A Karymov
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, USA
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DNA binding to RecD: role of the 1B domain in SF1B helicase activity. EMBO J 2008; 27:2222-9. [PMID: 18668125 DOI: 10.1038/emboj.2008.144] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Accepted: 06/30/2008] [Indexed: 11/08/2022] Open
Abstract
The molecular mechanism of superfamily 1Balpha helicases remains unclear. We present here the crystal structure of the RecD2 helicase from Deinococcus radiodurans at 2.2-A resolution. The structure reveals the folds of the 1B and 2B domains of RecD that were poorly ordered in the structure of the Escherichia coli RecBCD enzyme complex reported previously. The 2B domain adopts an SH3 fold which, although common in eukaryotes, is extremely rare in bacterial systems. In addition, the D. radiodurans RecD2 structure has aided us in deciphering lower resolution (3.6 A) electron density maps for the E. coli RecBCD enzyme in complex with a long DNA substrate that interacts with the RecD subunit. Taken together, these structures indicated an important role for the 1B domain of RecD, a beta-hairpin that extends from the surface of the 1A domain and interacts with the DNA substrate. On the basis of these structural data, we designed a mutant RecD2 helicase that lacks this pin. The 'pin-less' mutant protein is a fully active ssDNA-dependent ATPase but totally lacks helicase activity.
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Svozil D, Kalina J, Omelka M, Schneider B. DNA conformations and their sequence preferences. Nucleic Acids Res 2008; 36:3690-706. [PMID: 18477633 PMCID: PMC2441783 DOI: 10.1093/nar/gkn260] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 04/17/2008] [Accepted: 04/18/2008] [Indexed: 01/08/2023] Open
Abstract
The geometry of the phosphodiester backbone was analyzed for 7739 dinucleotides from 447 selected crystal structures of naked and complexed DNA. Ten torsion angles of a near-dinucleotide unit have been studied by combining Fourier averaging and clustering. Besides the known variants of the A-, B- and Z-DNA forms, we have also identified combined A + B backbone-deformed conformers, e.g. with alpha/gamma switches, and a few conformers with a syn orientation of bases occurring e.g. in G-quadruplex structures. A plethora of A- and B-like conformers show a close relationship between the A- and B-form double helices. A comparison of the populations of the conformers occurring in naked and complexed DNA has revealed a significant broadening of the DNA conformational space in the complexes, but the conformers still remain within the limits defined by the A- and B- forms. Possible sequence preferences, important for sequence-dependent recognition, have been assessed for the main A and B conformers by means of statistical goodness-of-fit tests. The structural properties of the backbone in quadruplexes, junctions and histone-core particles are discussed in further detail.
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Affiliation(s)
- Daniel Svozil
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, CZ-166 10 Prague and Jaroslav Hájek Center for Theoretical and Applied Statistics, Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University, Sokolovská 83, CZ-186 75 Prague, Czech Republic
| | - Jan Kalina
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, CZ-166 10 Prague and Jaroslav Hájek Center for Theoretical and Applied Statistics, Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University, Sokolovská 83, CZ-186 75 Prague, Czech Republic
| | - Marek Omelka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, CZ-166 10 Prague and Jaroslav Hájek Center for Theoretical and Applied Statistics, Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University, Sokolovská 83, CZ-186 75 Prague, Czech Republic
| | - Bohdan Schneider
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, CZ-166 10 Prague and Jaroslav Hájek Center for Theoretical and Applied Statistics, Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University, Sokolovská 83, CZ-186 75 Prague, Czech Republic
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38
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Witte G, Hartung S, Büttner K, Hopfner KP. Structural biochemistry of a bacterial checkpoint protein reveals diadenylate cyclase activity regulated by DNA recombination intermediates. Mol Cell 2008; 30:167-78. [PMID: 18439896 DOI: 10.1016/j.molcel.2008.02.020] [Citation(s) in RCA: 304] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 01/25/2008] [Accepted: 02/20/2008] [Indexed: 12/27/2022]
Abstract
To reveal mechanisms of DNA damage checkpoint initiation, we structurally and biochemically analyzed DisA, a protein that controls a Bacillus subtilis sporulation checkpoint in response to DNA double-strand breaks. We find that DisA forms a large octamer that consists of an array of an uncharacterized type of nucleotide-binding domain along with two DNA-binding regions related to the Holliday junction recognition protein RuvA. Remarkably, the nucleotide-binding domains possess diadenylate cyclase activity. The resulting cyclic diadenosine phosphate, c-di-AMP, is reminiscent but distinct from c-di-GMP, an emerging prokaryotic regulator of complex cellular processes. Diadenylate cyclase activity is unaffected by linear DNA or DNA ends but strongly suppressed by branched nucleic acids such as Holliday junctions. Our data indicate that DisA signals DNA structures that interfere with chromosome segregation via c-di-AMP. Identification of the diadenylate cyclase domain in other eubacterial and archaeal proteins implies a more general role for c-di-AMP in prokaryotes.
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Affiliation(s)
- Gregor Witte
- Munich Center for Advanced Photonics, Department of Chemistry and Biochemistry, Gene Center, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, D-81377 Munich, Germany
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39
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Lestienne PP, Boudsocq F, Bonnet JE. Initiation of DNA replication by a third parallel DNA strand bound in a triple-helix manner leads to strand invasion. Biochemistry 2008; 47:5689-98. [PMID: 18454553 DOI: 10.1021/bi702318g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
According to current knowledge, DNA polymerases accommodate only two polynucleotide strands in their catalytic site: the template and the primer to be elongated. Here we show that in addition to these two polynucleotide strands, HIV-1 and AMV reverse transcriptases, human DNA polymerases beta, gamma, and lambda, and the archaebacterial Dpo4 can elongate 10-nucleotide primers bound in a triple-helix manner to hairpin duplex DNA tethered by a few thymidine residues. The elongation occurs when the primer is parallel to the homologous strand. This feature was confirmed by using complementary single-stranded DNA with restricted nucleotide composition which bound polypurine and polypyrimidine primers at an asymmetric site. The results unambiguously confirmed the previous experiments, showing binding of the primer strand parallel to the homologous sequence. The common feature of these DNA polymerases is that they all elongated dG-rich primers, whereas they behaved differently when other polynucleotide sequences were used. Interestingly, only five to seven dG residues at similar positions between the primer and its binding site can allow elongation, which may even be facilitated by a single C/C mismatch. We suggest that DNA polymerases displace the primer form Hoogsteen bonds to from Watson-Crick pairings, enabling subsequent priming of replication. These experiments indicate that DNA polymerases may bind three DNA strands, as RNA polymerases do, and provide a molecular basis for 3'-OH invasion at short similar sequences in the DNA double helix, yielding potential DNA rearrangements upon single-strand breakage.
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Affiliation(s)
- Patrick P Lestienne
- Université Victor Segalen Bordeaux 2, Laboratoire de Pharmacologie des Agents Anticancéreux, EAD 515, Institut Bergonié, F-33076 Bordeaux, France.
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40
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Baharoglu Z, Bradley AS, Le Masson M, Tsaneva I, Michel B. ruvA Mutants that resolve Holliday junctions but do not reverse replication forks. PLoS Genet 2008; 4:e1000012. [PMID: 18369438 PMCID: PMC2265524 DOI: 10.1371/journal.pgen.1000012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 01/28/2008] [Indexed: 01/08/2023] Open
Abstract
RuvAB and RuvABC complexes catalyze branch migration and resolution of Holliday junctions (HJs) respectively. In addition to their action in the last steps of homologous recombination, they process HJs made by replication fork reversal, a reaction which occurs at inactivated replication forks by the annealing of blocked leading and lagging strand ends. RuvAB was recently proposed to bind replication forks and directly catalyze their conversion into HJs. We report here the isolation and characterization of two separation-of-function ruvA mutants that resolve HJs, based on their capacity to promote conjugational recombination and recombinational repair of UV and mitomycin C lesions, but have lost the capacity to reverse forks. In vivo and in vitro evidence indicate that the ruvA mutations affect DNA binding and the stimulation of RuvB helicase activity. This work shows that RuvA's actions at forks and at HJs can be genetically separated, and that RuvA mutants compromised for fork reversal remain fully capable of homologous recombination. DNA replication is the process by which DNA strands are copied to ensure the transmission of the genetic material to daughter cells. Chromosome replication is not a continuous process but is subjected to accidental arrests, owing to the encounter of obstacles or to the dysfunctioning of a replication protein. In bacteria, inactivated replication forks restart but they are most often remodeled before restarting. Interestingly, enzymes involved in homologous recombination, the process that rearranges chromosomes, are also involved in fork-remodeling reactions. The subject of the present study is RuvAB, a highly conserved bacterial complex used as the model enzyme for resolution of recombination intermediates, which we found to also act at blocked forks. We describe here the isolation and characterization of ruvA mutants that have specifically lost the capability to act at inactivated replication forks, although they remain fully capable of homologous recombination. The existence of such ruvA mutants, their properties and those of the purified RuvA mutant proteins, indicate that the action of RuvAB at replication forks is more demanding that its action at recombination intermediates, but have nevertheless been preserved during evolution.
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Affiliation(s)
- Zeynep Baharoglu
- CNRS, Centre de Génétique Moléculaire, UPR 2167, Gif-sur-Yvette, France
- Université Paris-Sud, Orsay, France
- Université Pierre et Marie Curie-Paris 6, Paris, France
| | - Alison Sylvia Bradley
- UCL Department of Biochemistry and Molecular Biology, University College London, London, United Kingdom
| | - Marie Le Masson
- CNRS, Centre de Génétique Moléculaire, UPR 2167, Gif-sur-Yvette, France
- Université Paris-Sud, Orsay, France
- Université Pierre et Marie Curie-Paris 6, Paris, France
| | - Irina Tsaneva
- UCL Department of Biochemistry and Molecular Biology, University College London, London, United Kingdom
| | - Bénédicte Michel
- CNRS, Centre de Génétique Moléculaire, UPR 2167, Gif-sur-Yvette, France
- Université Paris-Sud, Orsay, France
- Université Pierre et Marie Curie-Paris 6, Paris, France
- * E-mail:
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41
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Mountford CP, Buck AH, Campbell CJ, Dickinson P, Ferapontova EE, Terry JG, Beattie JS, Walton AJ, Ghazal P, Mount AR, Crain J. Molecular Recognition with DNA Nanoswitches: Effects of Single Base Mutations on Structure. J Phys Chem B 2008; 112:2439-44. [DOI: 10.1021/jp073817o] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- C. P. Mountford
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - A. H. Buck
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - C. J. Campbell
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - P. Dickinson
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - E. E. Ferapontova
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - J. G. Terry
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - J. S. Beattie
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - A. J. Walton
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - P. Ghazal
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - A. R. Mount
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
| | - J. Crain
- School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom, The Division of Pathway Medicine, The University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB Scotland, United Kingdom, School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom, Institute of Integrated Systems, Scottish Microelectronics Centre, School of Engineering and Electronics, University of Edinburgh, Edinburgh, EH9
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42
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Fujiwara Y, Mayanagi K, Morikawa K. Functional significance of octameric RuvA for a branch migration complex from Thermus thermophilus. Biochem Biophys Res Commun 2007; 366:426-31. [PMID: 18068124 DOI: 10.1016/j.bbrc.2007.11.149] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 11/26/2007] [Indexed: 11/25/2022]
Abstract
The RuvAB complex promotes migration of Holliday junction at the late stage of homologous recombination. The RuvA tetramer specifically recognizes Holliday junction to form two types of complexes. A single tetramer is bound to the open configuration of the junction DNA in complex I, while the octameric RuvA core structure sandwiches the same junction in complex II. The hexameric RuvB rings, symmetrically bound to both sides of RuvA on Holliday junction, pump out DNA duplexes, depending upon ATP hydrolysis. We investigated functional differences between the wild-type RuvA from Thermus thermophilus and mutants impaired the ability of complex II formation. These mutant RuvA, exclusively forming complex I, reduced activities of branch migration and ATP hydrolysis, suggesting that the octameric RuvA is essential for efficient branch migration. Together with our recent electron microscopic analysis, this finding provides important insights into functional roles of complex II in the coordinated branch migration mechanism.
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Affiliation(s)
- Yoshie Fujiwara
- Graduate School of Engineering Science, Osaka University, 1-3, Machikaneyama, Toyonaka, Osaka 560-8531, Japan
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43
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Mayanagi K, Fujiwara Y, Miyata T, Morikawa K. Electron microscopic single particle analysis of a tetrameric RuvA/RuvB/Holliday junction DNA complex. Biochem Biophys Res Commun 2007; 365:273-8. [PMID: 17981150 DOI: 10.1016/j.bbrc.2007.10.165] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Accepted: 10/25/2007] [Indexed: 11/30/2022]
Abstract
During the late stage of homologous recombination in prokaryotes, RuvA binds to the Holliday junction intermediate and executes branch migration in association with RuvB. The RuvA subunits form two distinct complexes with the Holliday junction: complex I with the single RuvA tetramer on one side of the four way junction DNA, and complex II with two tetramers on both sides. To investigate the functional roles of complexes I and II, we mutated two residues of RuvA (L125D and E126K) to prevent octamer formation. An electron microscopic analysis indicated that the mutant RuvA/RuvB/Holliday junction DNA complex formed the characteristic tripartite structure, with only one RuvA tetramer bound to one side of the Holliday junction, demonstrating the unexpected stability of this complex. The novel bent images of the complex revealed an intriguing morphological similarity to the structure of SV40 large T antigen, which belongs to the same AAA+ family as RuvB.
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Affiliation(s)
- Kouta Mayanagi
- Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama, Shiga 526-0829, Japan.
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44
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45
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Biertümpfel C, Yang W, Suck D. Crystal structure of T4 endonuclease VII resolving a Holliday junction. Nature 2007; 449:616-20. [PMID: 17873859 DOI: 10.1038/nature06152] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 08/07/2007] [Indexed: 11/08/2022]
Abstract
Holliday proposed a four-way DNA junction as an intermediate in homologous recombination, and such Holliday junctions have since been identified as a central component in DNA recombination and repair. Phage T4 endonuclease VII (endo VII) was the first enzyme shown to resolve Holliday junctions into duplex DNAs by introducing symmetrical nicks in equivalent strands. Several Holliday junction resolvases have since been characterized, but an atomic structure of a resolvase complex with a Holliday junction remained elusive. Here we report the crystal structure of an inactive T4 endo VII(N62D) complexed with an immobile four-way junction with alternating arm lengths of 10 and 14 base pairs. The junction is a hybrid of the conventional square-planar and stacked-X conformation. Endo VII protrudes into the junction point from the minor groove side, opening it to a 14 A x 32 A parallelogram. This interaction interrupts the coaxial stacking, yet every base pair surrounding the junction remains intact. Additional interactions involve the positively charged protein and DNA phosphate backbones. Each scissile phosphate that is two base pairs from the crossover interacts with a Mg2+ ion in the active site. The similar overall shape and surface charge potential of the Holliday junction resolvases endo VII, RuvC, Ydc2, Hjc and RecU, despite having different folds, active site composition and DNA sequence preference, suggest a conserved binding mode for Holliday junctions.
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Affiliation(s)
- Christian Biertümpfel
- National Institute of Diabetes and Digestive and Kidney Diseases, Laboratory of Molecular Biology, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
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46
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Hadden JM, Déclais AC, Carr SB, Lilley DMJ, Phillips SEV. The structural basis of Holliday junction resolution by T7 endonuclease I. Nature 2007; 449:621-4. [PMID: 17873858 DOI: 10.1038/nature06158] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Accepted: 08/07/2007] [Indexed: 11/09/2022]
Abstract
The four-way (Holliday) DNA junction is the central intermediate in homologous recombination, a ubiquitous process that is important in DNA repair and generation of genetic diversity. The penultimate stage of recombination requires resolution of the DNA junction into nicked-duplex species by the action of a junction-resolving enzyme, examples of which have been identified in a wide variety of organisms. These enzymes are nucleases that are highly selective for the structure of branched DNA. The mechanism of this selectivity has, however, been unclear in the absence of structural data. Here we present the crystal structure of the junction-resolving enzyme phage T7 endonuclease I in complex with a synthetic four-way DNA junction. Although the enzyme is structure-selective, significant induced fit occurs in the interaction, with changes in the structure of both the protein and the junction. The dimeric enzyme presents two binding channels that contact the backbones of the junction's helical arms over seven nucleotides. These interactions effectively measure the relative orientations and positions of the arms of the junction, thereby ensuring that binding is selective for branched DNA that can achieve this geometry.
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Affiliation(s)
- Jonathan M Hadden
- Astbury Centre for Structural Molecular Biology, Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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47
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Model for RuvAB-mediated branch migration of Holliday junctions. J Theor Biol 2007; 249:566-73. [PMID: 17919660 DOI: 10.1016/j.jtbi.2007.08.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2007] [Revised: 08/27/2007] [Accepted: 08/27/2007] [Indexed: 11/21/2022]
Abstract
During RuvAB-mediated Holliday-junction migration two opposite arms of double-stranded DNA (dsDNA) are driven to translocate unidirectional by two respective ring-like hexameric RuvB proteins. However, how the RuvB protein, powered by ATP hydrolysis, drives unidirectional translocation of dsDNA is not clear. Here a model is presented for this mechanochemical-coupling mechanism. In the model, the unidirectional translocation is resulted from both the ATP hydrolysis-induced rotation (power stroke) of the RuvB subunits and the passage of the strong DNA binding from the previous to next RuvB subunits during the sequential ATPase activities around the ring. Using the model, the relationship between the power-stroke size, the step size of DNA translocation and the ratio of the rotational rate of DNA over that of RuvB relative to RuvA is predicted.
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Mazina OM, Rossi MJ, Thomaä NH, Mazin AV. Interactions of human rad54 protein with branched DNA molecules. J Biol Chem 2007; 282:21068-80. [PMID: 17545145 DOI: 10.1074/jbc.m701992200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The Rad54 protein plays an important role during homologous recombination in eukaryotes. The protein belongs to the Swi2/Snf2 family of ATP-dependent DNA translocases. We previously showed that yeast and human Rad54 (hRad54) specifically bind to Holliday junctions and promote branch migration. Here we examined the minimal DNA structural requirements for optimal hRad54 ATPase and branch migration activity. Although a 12-bp double-stranded DNA region of branched DNA is sufficient to induce ATPase activity, the minimal substrate that gave rise to optimal stimulation of the ATP hydrolysis rate consisted of two short double-stranded DNA arms, 15 bp each, combined with a 45-nucleotide single-stranded DNA branch. We showed that hRad54 binds preferentially to the open and not to the stacked conformation of branched DNA. Stoichiometric titration of hRad54 revealed formation of two types of hRad54 complexes with branched DNA substrates. The first of them, a dimer, is responsible for the ATPase activity of the protein. However, branch migration activity requires a significantly higher stoichiometry of hRad54, approximately 10 +/- 2 protein monomers/DNA molecule. This pleomorphism of hRad54 in formation of oligomeric complexes with DNA may correspond to multiple functions of the protein in homologous recombination.
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Affiliation(s)
- Olga M Mazina
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102-1192, USA
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Mount AR, Mountford CP, Evans SAG, Su TJ, Buck AH, Dickinson P, Campbell CJ, Keane LM, Terry JG, Beattie JS, Walton AJ, Ghazal P, Crain J. The stability and characteristics of a DNA Holliday junction switch. Biophys Chem 2006; 124:214-21. [PMID: 16716492 DOI: 10.1016/j.bpc.2006.03.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Accepted: 03/25/2006] [Indexed: 11/17/2022]
Abstract
A Holliday junction (HJ) consists of four DNA double helices, with a branch point discontinuity at the intersection of the component strands. At low ionic strength, the HJ adopts an open conformation, with four widely spaced arms, primarily due to strong electrostatic repulsion between the phosphate groups on the backbones. At high ionic strength, screening of this repulsion induces a switch to a more compact (closed) junction conformation. Fluorescent labelling with dyes placed on the HJ arms allows this conformational switch to be detected optically using fluorescence resonance energy transfer (FRET), producing a sensitive fluorescent output of the switch state. This paper presents a systematic and quantitative survey of the switch characteristics of such a labelled HJ. A short HJ (arm length 8 bp) is shown to be prone to dissociation at low switching ion concentration, whereas an HJ of arm length 12 bp is shown to be stable over all switching ion concentrations studied. The switching characteristics of this HJ have been systematically and quantitatively studied for a variety of switching ions, by measuring the required ion concentration, the sharpness of the switching transition and the fluorescent output intensity of the open and closed states. This stable HJ is shown to have favourable switch characteristics for a number of inorganic switching ions, making it a promising candidate for use in nanoscale biomolecular switch devices.
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Affiliation(s)
- A R Mount
- School of Chemistry, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JJ, UK.
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Macmaster R, Sedelnikova S, Baker PJ, Bolt EL, Lloyd RG, Rafferty JB. RusA Holliday junction resolvase: DNA complex structure--insights into selectivity and specificity. Nucleic Acids Res 2006; 34:5577-84. [PMID: 17028102 PMCID: PMC1636454 DOI: 10.1093/nar/gkl447] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We have determined the structure of a catalytically inactive D70N variant of the Escherichia coli RusA resolvase bound to a duplex DNA substrate that reveals critical protein-DNA interactions and permits a much clearer understanding of the interaction of the enzyme with a Holliday junction (HJ). The RusA enzyme cleaves HJs, the fourway DNA branchpoints formed by homologous recombination, by introducing symmetrical cuts in the phosphodiester backbone in a Mg2+ dependent reaction. Although, RusA shows a high level of selectivity for DNA junctions, preferring to bind fourway junctions over other substrates in vitro, it has also been shown to have appreciable affinity for duplex DNA. However, RusA does not show DNA cleavage activity with duplex substrates. Our structure suggests the possible basis for structural selectivity as well as sources of the sequence specificity observed for DNA cleavage by RusA.
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Affiliation(s)
| | | | | | - Edward L. Bolt
- Institute of Genetics, University of NottinghamQueen's Medical Centre, Nottingham NG7 2UH, UK
| | - Robert G. Lloyd
- Institute of Genetics, University of NottinghamQueen's Medical Centre, Nottingham NG7 2UH, UK
| | - John B. Rafferty
- To whom correspondence should be addressed. Tel: +44 114 222 2809; Fax: +44 114 222 2800;
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