1
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Bell SD. Form and function of archaeal genomes. Biochem Soc Trans 2022; 50:1931-1939. [PMID: 36511238 PMCID: PMC9764264 DOI: 10.1042/bst20221396] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 07/30/2023]
Abstract
A key maxim in modernist architecture is that 'form follows function'. While modernist buildings are hopefully the product of intelligent design, the architectures of chromosomes have been sculpted by the forces of evolution over many thousands of generations. In the following, I will describe recent advances in our understanding of chromosome architecture in the archaeal domain of life. Although much remains to be learned about the mechanistic details of archaeal chromosome organization, some general principles have emerged. At the 10-100 kb level, archaeal chromosomes have a conserved local organization reminiscent of bacterial genomes. In contrast, lineage-specific innovations appear to have imposed distinct large-scale architectural features. The ultimate functions of genomes are to store and to express genetic information. Gene expression profiles have been shown to influence chromosome architecture, thus their form follows function. However, local changes to chromosome conformation can also influence gene expression and therefore, in these instances, function follows form.
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Affiliation(s)
- Stephen D. Bell
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405, U.S.A
- Biology Department, Indiana University, Bloomington, IN 47405, U.S.A
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2
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Chromosome organization affects genome evolution in Sulfolobus archaea. Nat Microbiol 2022; 7:820-830. [PMID: 35618771 DOI: 10.1038/s41564-022-01127-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 04/21/2022] [Indexed: 12/16/2022]
Abstract
In all organisms, the DNA sequence and the structural organization of chromosomes affect gene expression. The extremely thermophilic crenarchaeon Sulfolobus has one circular chromosome with three origins of replication. We previously revealed that this chromosome has defined A and B compartments that have high and low gene expression, respectively. As well as higher levels of gene expression, the A compartment contains the origins of replication. To evaluate the impact of three-dimensional organization on genome evolution, we characterized the effect of replication origins and compartmentalization on primary sequence evolution in eleven Sulfolobus species. Using single-nucleotide polymorphism analyses, we found that distance from an origin of replication was associated with increased mutation rates in the B but not in the A compartment. The enhanced polymorphisms distal to replication origins suggest that replication termination may have a causal role in their generation. Further mutational analyses revealed that the sequences in the A compartment are less likely to be mutated, and that there is stronger purifying selection than in the B compartment. Finally, we applied the Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) to show that the B compartment is less accessible than the A compartment. Taken together, our data suggest that compartmentalization of chromosomal DNA can influence chromosome evolution in Sulfolobus. We propose that the A compartment serves as a haven for stable maintenance of gene sequences, while sequences in the B compartment can be diversified.
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3
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Agapov A, Olina A, Kulbachinskiy A. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3018-3041. [PMID: 35323981 PMCID: PMC8989532 DOI: 10.1093/nar/gkac174] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 02/26/2022] [Accepted: 03/03/2022] [Indexed: 11/14/2022] Open
Abstract
Cellular DNA is continuously transcribed into RNA by multisubunit RNA polymerases (RNAPs). The continuity of transcription can be disrupted by DNA lesions that arise from the activities of cellular enzymes, reactions with endogenous and exogenous chemicals or irradiation. Here, we review available data on translesion RNA synthesis by multisubunit RNAPs from various domains of life, define common principles and variations in DNA damage sensing by RNAP, and consider existing controversies in the field of translesion transcription. Depending on the type of DNA lesion, it may be correctly bypassed by RNAP, or lead to transcriptional mutagenesis, or result in transcription stalling. Various lesions can affect the loading of the templating base into the active site of RNAP, or interfere with nucleotide binding and incorporation into RNA, or impair RNAP translocation. Stalled RNAP acts as a sensor of DNA damage during transcription-coupled repair. The outcome of DNA lesion recognition by RNAP depends on the interplay between multiple transcription and repair factors, which can stimulate RNAP bypass or increase RNAP stalling, and plays the central role in maintaining the DNA integrity. Unveiling the mechanisms of translesion transcription in various systems is thus instrumental for understanding molecular pathways underlying gene regulation and genome stability.
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Affiliation(s)
- Aleksei Agapov
- Correspondence may also be addressed to Aleksei Agapov. Tel: +7 499 196 0015; Fax: +7 499 196 0015;
| | - Anna Olina
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute” Moscow 123182, Russia
| | - Andrey Kulbachinskiy
- To whom correspondence should be addressed. Tel: +7 499 196 0015; Fax: +7 499 196 0015;
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4
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Miyabayashi H, Sakai HD, Kurosawa N. DNA Polymerase B1 Binding Protein 1 Is Important for DNA Repair by Holoenzyme PolB1 in the Extremely Thermophilic Crenarchaeon Sulfolobus acidocaldarius. Microorganisms 2021; 9:microorganisms9020439. [PMID: 33672533 PMCID: PMC7923795 DOI: 10.3390/microorganisms9020439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
DNA polymerase B1 (PolB1) is a member of the B-family DNA polymerase family and is a replicative DNA polymerase in Crenarchaea. PolB1 is responsible for the DNA replication of both the leading and lagging strands in the thermophilic crenarchaeon Sulfolobus acidocaldarius. Recently, two subunits, PolB1-binding protein (PBP)1 and PBP2, were identified in Saccharolobus solfataricus. Previous in vitro studies suggested that PBP1 and PBP2 influence the core activity of apoenzyme PolB1 (apo-PolB1). PBP1 contains a C-terminal acidic tail and modulates the strand-displacement synthesis activity of PolB1 during the synthesis of Okazaki fragments. PBP2 modestly enhances the DNA polymerase activity of apo-PolB1. These subunits are present in Sulfolobales, Acidilobales, and Desulfurococcales, which belong to Crenarchaea. However, it has not been determined whether these subunits are essential for the activity of apo-PolB1. In this study, we constructed a pbp1 deletion strain in S. acidocaldarius and characterized its phenotypes. However, a pbp2 deletion strain was not obtained, indicating that PBP2 is essential for replication by holoenzyme PolB1. A pbp1 deletion strain was sensitive to various types of DNA damage and exhibited an increased mutation rate, suggesting that PBP1 contribute to the repair or tolerance of DNA damage by holoenzyme PolB1. The results of our study suggest that PBP1 is important for DNA repair by holoenzyme PolB1 in S. acidocaldarius.
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Affiliation(s)
- Hiroka Miyabayashi
- Department of Environmental Engineering for Symbiosis, Graduate School of Science and Engineering, Soka University, 1-236 Tangi-machi, Hachioji, Tokyo 192-8577, Japan;
| | - Hiroyuki D. Sakai
- Department of Science and Engineering for Sustainable Innovation, Faculty of Science and Engineering, Soka University, 1-236 Tangi-machi, Hachioji, Tokyo 192-8577, Japan;
| | - Norio Kurosawa
- Department of Environmental Engineering for Symbiosis, Graduate School of Science and Engineering, Soka University, 1-236 Tangi-machi, Hachioji, Tokyo 192-8577, Japan;
- Department of Science and Engineering for Sustainable Innovation, Faculty of Science and Engineering, Soka University, 1-236 Tangi-machi, Hachioji, Tokyo 192-8577, Japan;
- Correspondence: ; Tel.: +81-42-691-8175
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5
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Miyabayashi H, Jain R, Suzuki S, Grogan DW, Kurosawa N. PolB1 Is Sufficient for DNA Replication and Repair Under Normal Growth Conditions in the Extremely Thermophilic Crenarchaeon Sulfolobus acidocaldarius. Front Microbiol 2020; 11:613375. [PMID: 33424816 PMCID: PMC7785828 DOI: 10.3389/fmicb.2020.613375] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/30/2020] [Indexed: 01/12/2023] Open
Abstract
The thermophilic crenarchaeon Sulfolobus acidocaldarius has four DNA polymerases (DNAPs): PolB1, PolB2, PolB3, and Dbh (PolY). Previous in vitro studies suggested that PolB1 is the main replicative DNAP of Sulfolobales whereas PolB2 and Y-family polymerases Dpo4 (Saccharolobus solfataricus) or Dbh are involved in DNA repair and translesion DNA synthesis. On the other hand, there are various opinions about the role of PolB3, which remains to be clearly resolved. In order to examine the roles of the DNAPs of S. acidocaldarius through in vivo experiments, we constructed polB2, polB3, and dbh deletion strains and characterized their phenotypes. Efforts to construct a polB1 deletion strain were not successful; in contrast, it was possible to isolate triple gene-deletion strains lacking polB2, polB3, and dbh. The growth of these strains was nearly the same as that of the parent strains under normal growth conditions. The polB2, polB3, and dbh single-deletion strains were sensitive to some types of DNA-damaging treatments, but exhibited normal sensitivity to UV irradiation and several other damaging treatments. Overall, the genotype which exhibited the greatest sensitivity to the DNA-damaging treatments we tested was the ΔpolB2 ΔpolB3 combination, providing the first evidence of overlapping function for these two DNAPs in vivo. The results of our study strongly suggest that PolB1 is responsible for the DNA replication of both the leading and lagging strands and is sufficient to complete the repair of most DNA damage under normal growth conditions in S. acidocaldarius.
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Affiliation(s)
- Hiroka Miyabayashi
- Department of Environmental Engineering for Symbiosis, Graduate School of Science and Engineering, Soka University, Tokyo, Japan
| | - Rupal Jain
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Shoji Suzuki
- Department of Environmental Engineering for Symbiosis, Graduate School of Science and Engineering, Soka University, Tokyo, Japan
| | - Dennis W. Grogan
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Norio Kurosawa
- Department of Environmental Engineering for Symbiosis, Graduate School of Science and Engineering, Soka University, Tokyo, Japan
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6
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Pérez-Arnaiz P, Dattani A, Smith V, Allers T. Haloferax volcanii-a model archaeon for studying DNA replication and repair. Open Biol 2020; 10:200293. [PMID: 33259746 PMCID: PMC7776575 DOI: 10.1098/rsob.200293] [Citation(s) in RCA: 5] [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: 09/11/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022] Open
Abstract
The tree of life shows the relationship between all organisms based on their common ancestry. Until 1977, it comprised two major branches: prokaryotes and eukaryotes. Work by Carl Woese and other microbiologists led to the recategorization of prokaryotes and the proposal of three primary domains: Eukarya, Bacteria and Archaea. Microbiological, genetic and biochemical techniques were then needed to study the third domain of life. Haloferax volcanii, a halophilic species belonging to the phylum Euryarchaeota, has provided many useful tools to study Archaea, including easy culturing methods, genetic manipulation and phenotypic screening. This review will focus on DNA replication and DNA repair pathways in H. volcanii, how this work has advanced our knowledge of archaeal cellular biology, and how it may deepen our understanding of bacterial and eukaryotic processes.
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Affiliation(s)
| | | | | | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
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7
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Marshall CJ, Santangelo TJ. Archaeal DNA Repair Mechanisms. Biomolecules 2020; 10:E1472. [PMID: 33113933 PMCID: PMC7690668 DOI: 10.3390/biom10111472] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 12/29/2022] Open
Abstract
Archaea often thrive in environmental extremes, enduring levels of heat, pressure, salinity, pH, and radiation that prove intolerable to most life. Many environmental extremes raise the propensity for DNA damaging events and thus, impact DNA stability, placing greater reliance on molecular mechanisms that recognize DNA damage and initiate accurate repair. Archaea can presumably prosper in harsh and DNA-damaging environments in part due to robust DNA repair pathways but surprisingly, no DNA repair pathways unique to Archaea have been described. Here, we review the most recent advances in our understanding of archaeal DNA repair. We summarize DNA damage types and their consequences, their recognition by host enzymes, and how the collective activities of many DNA repair pathways maintain archaeal genomic integrity.
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Affiliation(s)
| | - Thomas J. Santangelo
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA;
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8
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Ghodke H, Ho HN, van Oijen AM. Single-molecule live-cell imaging visualizes parallel pathways of prokaryotic nucleotide excision repair. Nat Commun 2020; 11:1477. [PMID: 32198385 PMCID: PMC7083872 DOI: 10.1038/s41467-020-15179-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 02/23/2020] [Indexed: 01/01/2023] Open
Abstract
In the model organism Escherichia coli, helix distorting lesions are recognized by the UvrAB damage surveillance complex in the global genomic nucleotide excision repair pathway (GGR). Alternately, during transcription-coupled repair (TCR), UvrA is recruited to Mfd at sites of RNA polymerases stalled by lesions. Ultimately, damage recognition is mediated by UvrA, followed by verification by UvrB. Here we characterize the differences in the kinetics of interactions of UvrA with Mfd and UvrB by following functional, fluorescently tagged UvrA molecules in live TCR-deficient or wild-type cells. The lifetimes of UvrA in Mfd-dependent or Mfd-independent interactions in the absence of exogenous DNA damage are comparable in live cells, and are governed by UvrB. Upon UV irradiation, the lifetimes of UvrA strongly depended on, and matched those of Mfd. Overall, we illustrate a non-perturbative, imaging-based approach to quantify the kinetic signatures of damage recognition enzymes participating in multiple pathways in cells. In Escherichia coli, the UvrAB damage sensor recognizes helix-distorting lesions by itself or via Mfd bound to stalled RNA polymerase. Here authors use single-molecule fluorescence imaging to quantify the kinetic signatures of interactions of UvrA with Mfd and UvrB in live cells.
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Affiliation(s)
- Harshad Ghodke
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
| | - Han Ngoc Ho
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Antoine M van Oijen
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
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9
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Ho HN, van Oijen AM, Ghodke H. Single-molecule imaging reveals molecular coupling between transcription and DNA repair machinery in live cells. Nat Commun 2020; 11:1478. [PMID: 32198374 PMCID: PMC7083905 DOI: 10.1038/s41467-020-15182-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 02/23/2020] [Indexed: 01/20/2023] Open
Abstract
The Escherichia coli transcription-repair coupling factor Mfd displaces stalled RNA polymerase and delivers the stall site to the nucleotide excision repair factors UvrAB for damage detection. Whether this handoff from RNA polymerase to UvrA occurs via the Mfd-UvrA2-UvrB complex or alternate reaction intermediates in cells remains unclear. Here, we visualise Mfd in actively growing cells and determine the catalytic requirements for faithful recruitment of nucleotide excision repair proteins. We find that ATP hydrolysis by UvrA governs formation and disassembly of the Mfd-UvrA2 complex. Further, Mfd-UvrA2-UvrB complexes formed by UvrB mutants deficient in DNA loading and damage recognition are impaired in successful handoff. Our single-molecule dissection of interactions of Mfd with its partner proteins inside live cells shows that the dissociation of Mfd is tightly coupled to successful loading of UvrB, providing a mechanism via which loading of UvrB occurs in a strand-specific manner.
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Affiliation(s)
- Han Ngoc Ho
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Antoine M van Oijen
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Harshad Ghodke
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
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10
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Blombach F, Matelska D, Fouqueau T, Cackett G, Werner F. Key Concepts and Challenges in Archaeal Transcription. J Mol Biol 2019; 431:4184-4201. [PMID: 31260691 DOI: 10.1016/j.jmb.2019.06.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 12/17/2022]
Abstract
Transcription is enabled by RNA polymerase and general factors that allow its progress through the transcription cycle by facilitating initiation, elongation and termination. The transitions between specific stages of the transcription cycle provide opportunities for the global and gene-specific regulation of gene expression. The exact mechanisms and the extent to which the different steps of transcription are exploited for regulation vary between the domains of life, individual species and transcription units. However, a surprising degree of conservation is apparent. Similar key steps in the transcription cycle can be targeted by homologous or unrelated factors providing insights into the mechanisms of RNAP and the evolution of the transcription machinery. Archaea are bona fide prokaryotes but employ a eukaryote-like transcription system to express the information of bacteria-like genomes. Thus, archaea provide the means not only to study transcription mechanisms of interesting model systems but also to test key concepts of regulation in this arena. In this review, we discuss key principles of archaeal transcription, new questions that still await experimental investigation, and how novel integrative approaches hold great promise to fill this gap in our knowledge.
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Affiliation(s)
- Fabian Blombach
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
| | - Dorota Matelska
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Thomas Fouqueau
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Gwenny Cackett
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Finn Werner
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
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11
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White MF, Allers T. DNA repair in the archaea-an emerging picture. FEMS Microbiol Rev 2018; 42:514-526. [PMID: 29741625 DOI: 10.1093/femsre/fuy020] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/02/2018] [Indexed: 12/12/2022] Open
Abstract
There has long been a fascination in the DNA repair pathways of archaea, for two main reasons. Firstly, many archaea inhabit extreme environments where the rate of physical damage to DNA is accelerated. These archaea might reasonably be expected to have particularly robust or novel DNA repair pathways to cope with this. Secondly, the archaea have long been understood to be a lineage distinct from the bacteria, and to share a close relationship with the eukarya, particularly in their information processing systems. Recent discoveries suggest the eukarya arose from within the archaeal domain, and in particular from lineages related to the TACK superphylum and Lokiarchaea. Thus, archaeal DNA repair proteins and pathways can represent a useful model system. This review focuses on recent advances in our understanding of archaeal DNA repair processes including base excision repair, nucleotide excision repair, mismatch repair and double-strand break repair. These advances are discussed in the context of the emerging picture of the evolution and relationship of the three domains of life.
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Affiliation(s)
- Malcolm F White
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, Fife KY16 9ST, UK
| | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK
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12
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Jones DL, Baxter BK. DNA Repair and Photoprotection: Mechanisms of Overcoming Environmental Ultraviolet Radiation Exposure in Halophilic Archaea. Front Microbiol 2017; 8:1882. [PMID: 29033920 PMCID: PMC5626843 DOI: 10.3389/fmicb.2017.01882] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/14/2017] [Indexed: 12/31/2022] Open
Abstract
Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV) radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidines, or indirectly from oxidative damage, which may ultimately result in mutation and cell death. As such, these microorganisms have evolved a number of strategies to navigate the threat of DNA damage, which we differentiate into two categories: DNA repair and photoprotection. Photoprotection encompasses damage avoidance strategies that serve as a "first line of defense," and in halophilic archaea include pigmentation by carotenoids, mechanisms of oxidative damage avoidance, polyploidy, and genomic signatures that make DNA less susceptible to photodamage. Photolesions that do arise are addressed by a number of DNA repair mechanisms that halophilic archaea efficiently utilize, which include photoreactivation, nucleotide excision repair, base excision repair, and homologous recombination. This review seeks to place DNA damage, repair, and photoprotection in the context of halophilic archaea and the solar radiation of their hypersaline environments. We also provide new insight into the breadth of strategies and how they may work together to produce remarkable UV-resistance for these microorganisms.
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Affiliation(s)
| | - Bonnie K. Baxter
- Department of Biology, Great Salt Lake Institute, Westminster College, Salt Lake City, UT, United States
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13
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Deaconescu AM, Suhanovsky MM. From Mfd to TRCF and Back Again-A Perspective on Bacterial Transcription-coupled Nucleotide Excision Repair. Photochem Photobiol 2016; 93:268-279. [PMID: 27859304 DOI: 10.1111/php.12661] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 10/08/2016] [Indexed: 12/17/2022]
Abstract
Photochemical and other reactions on DNA cause damage and corrupt genetic information. To counteract this damage, organisms have evolved intricate repair mechanisms that often crosstalk with other DNA-based processes such as transcription. Intriguing observations in the late 1980s and early 1990s led to the discovery of transcription-coupled repair (TCR), a subpathway of nucleotide excision repair. TCR, found in all domains of life, prioritizes for repair lesions located in the transcribed DNA strand, directly read by RNA polymerase. Here, we give a historical overview of developments in the field of bacterial TCR, starting from the pioneering work of Evelyn Witkin and Aziz Sancar, which led to the identification of the first transcription-repair coupling factor (the Mfd protein), to recent studies that have uncovered alternative TCR pathways and regulators.
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Affiliation(s)
- Alexandra M Deaconescu
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI
| | - Margaret M Suhanovsky
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI
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14
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Barbier E, Lagorce A, Hachemi A, Dutertre M, Gorlas A, Morand L, Saint-Pierre C, Ravanat JL, Douki T, Armengaud J, Gasparutto D, Confalonieri F, Breton J. Oxidative DNA Damage and Repair in the Radioresistant Archaeon Thermococcus gammatolerans. Chem Res Toxicol 2016; 29:1796-1809. [PMID: 27676238 DOI: 10.1021/acs.chemrestox.6b00128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The hyperthermophilic archaeon Thermococcus gammatolerans can resist huge doses of γ-irradiation, up to 5.0 kGy, without loss of viability. The potential to withstand such harsh conditions is probably due to complementary passive and active mechanisms, including repair of damaged chromosomes. In this work, we documented the formation and repair of oxidative DNA lesions in T. gammatolerans. The basal level of the oxidized nucleoside, 8-oxo-2'-deoxyguanosine (8-oxo-dGuo), was established at 9.2 (± 0.9) 8-oxo-dGuo per 106 nucleosides, a higher level than those usually measured in eukaryotic cells or bacteria. A significant increase in oxidative damage, i.e., up to 24.2 (± 8.0) 8-oxo-dGuo/106 nucleosides, was measured for T. gammatolerans exposed to a 5.0 kGy dose of γ-rays. Surprisingly, the yield of radiation-induced modifications was lower than those previously observed for human cells exposed to doses corresponding to a few grays. One hour after irradiation, 8-oxo-dGuo levels were significantly reduced, indicating an efficient repair. Two putative base excision repair (BER) enzymes, TGAM_1277 and TGAM_1653, were demonstrated both by proteomics and transcriptomics to be present in the cells without exposure to ionizing radiation. Their transcripts were moderately upregulated after gamma irradiation. After heterologous production and purification of these enzymes, biochemical assays based on electrophoresis and MALDI-TOF (matrix-assisted laser desorption ionization-time of flight) mass spectrometry indicated that both have a β-elimination cleavage activity. TGAM_1653 repairs 8-oxo-dGuo, whereas TGAM_1277 is also able to remove lesions affecting pyrimidines (1-[2-deoxy-β-d-erythro-pentofuranosyl]-5-hydroxyhydantoin (5-OH-dHyd) and 1-[2-deoxy-β-d-erythro-pentofuranosyl]-5-hydroxy-5-methylhydantoin (5-OH-5-Me-dHyd)). This work showed that in normal growth conditions or in the presence of a strong oxidative stress, T. gammatolerans has the potential to rapidly reduce the extent of DNA oxidation, with at least these two BER enzymes as bodyguards with distinct substrate ranges.
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Affiliation(s)
- Ewa Barbier
- University of Grenoble Alpes, INAC, LCIB , F-38000 Grenoble, France.,CEA, INAC, SyMMES, F-38000 Grenoble, France
| | - Arnaud Lagorce
- University of Paris-Sud, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Orsay, France.,University of Perpignan, IHPE - UMR 5244 CNRS/IFREMER/Univ. Montpellier, Montpellier, F-34095, France
| | - Amine Hachemi
- University of Paris-Sud, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Orsay, France
| | - Murielle Dutertre
- University of Paris-Sud, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Orsay, France
| | - Aurore Gorlas
- University of Paris-Sud, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Orsay, France
| | - Lucie Morand
- University of Grenoble Alpes, INAC, LCIB , F-38000 Grenoble, France.,CEA, INAC, SyMMES, F-38000 Grenoble, France
| | - Christine Saint-Pierre
- University of Grenoble Alpes, INAC, LCIB , F-38000 Grenoble, France.,CEA, INAC, SyMMES, F-38000 Grenoble, France
| | - Jean-Luc Ravanat
- University of Grenoble Alpes, INAC, LCIB , F-38000 Grenoble, France.,CEA, INAC, SyMMES, F-38000 Grenoble, France
| | - Thierry Douki
- University of Grenoble Alpes, INAC, LCIB , F-38000 Grenoble, France.,CEA, INAC, SyMMES, F-38000 Grenoble, France
| | - Jean Armengaud
- CEA, DSV-Li2D, Laboratory "Innovative Technologies for Detection and Diagnostics", BP 17171, Bagnols-sur-Cèze, F-30207, France
| | - Didier Gasparutto
- University of Grenoble Alpes, INAC, LCIB , F-38000 Grenoble, France.,CEA, INAC, SyMMES, F-38000 Grenoble, France
| | - Fabrice Confalonieri
- University of Paris-Sud, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Orsay, France
| | - Jean Breton
- University of Grenoble Alpes, INAC, LCIB , F-38000 Grenoble, France.,CEA, INAC, SyMMES, F-38000 Grenoble, France
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15
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Stantial N, Dumpe J, Pietrosimone K, Baltazar F, Crowley DJ. Transcription-coupled repair of UV damage in the halophilic archaea. DNA Repair (Amst) 2016; 41:63-68. [DOI: 10.1016/j.dnarep.2016.03.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 02/22/2016] [Accepted: 03/21/2016] [Indexed: 12/01/2022]
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16
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Pestov NA, Gerasimova NS, Kulaeva OI, Studitsky VM. Structure of transcribed chromatin is a sensor of DNA damage. SCIENCE ADVANCES 2015; 1:e1500021. [PMID: 26601207 PMCID: PMC4646769 DOI: 10.1126/sciadv.1500021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/03/2015] [Indexed: 06/05/2023]
Abstract
Early detection and repair of damaged DNA is essential for cell functioning and survival. Although multiple cellular systems are involved in the repair of single-strand DNA breaks (SSBs), it remains unknown how SSBs present in the nontemplate strand (NT-SSBs) of DNA organized in chromatin are detected. The effect of NT-SSBs on transcription through chromatin by RNA polymerase II was studied. NT-SSBs localized in the promoter-proximal region of nucleosomal DNA and hidden in the nucleosome structure can induce a nearly quantitative arrest of RNA polymerase downstream of the break, whereas more promoter-distal SSBs moderately facilitate transcription. The location of the arrest sites on nucleosomal DNA suggests that formation of small intranucleosomal DNA loops causes the arrest. This mechanism likely involves relief of unconstrained DNA supercoiling accumulated during transcription through chromatin by NT-SSBs. These data suggest the existence of a novel chromatin-specific mechanism that allows the detection of NT-SSBs by the transcribing enzyme.
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Affiliation(s)
- Nikolay A. Pestov
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | | | - Olga I. Kulaeva
- Biology Faculty, Lomonosov Moscow State University, Moscow, Russia
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Vasily M. Studitsky
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
- Biology Faculty, Lomonosov Moscow State University, Moscow, Russia
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
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17
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Understanding DNA Repair in Hyperthermophilic Archaea: Persistent Gaps and Other Reasons to Focus on the Fork. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2015; 2015:942605. [PMID: 26146487 PMCID: PMC4471258 DOI: 10.1155/2015/942605] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/21/2015] [Indexed: 11/17/2022]
Abstract
Although hyperthermophilic archaea arguably have a great need for efficient DNA repair, they lack members of several DNA repair protein families broadly conserved among bacteria and eukaryotes. Conversely, the putative DNA repair genes that do occur in these archaea often do not generate the expected phenotype when deleted. The prospect that hyperthermophilic archaea have some unique strategies for coping with DNA damage and replication errors has intellectual and technological appeal, but resolving this question will require alternative coping mechanisms to be proposed and tested experimentally. This review evaluates a combination of four enigmatic properties that distinguishes the hyperthermophilic archaea from all other organisms: DNA polymerase stalling at dU, apparent lack of conventional NER, lack of MutSL homologs, and apparent essentiality of homologous recombination proteins. Hypothetical damage-coping strategies that could explain this set of properties may provide new starting points for efforts to define how archaea differ from conventional models of DNA repair and replication fidelity.
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18
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Abstract
ABSTRACT
Low rates of replication errors in chromosomal genes of
Sulfolobus
spp. demonstrate that these extreme thermoacidophiles can maintain genome integrity in environments with high temperature and low pH. In contrast to this genetic stability, we observed unusually frequent mutation of the β-
d
-glycosidase gene (
lacS
) of a shuttle plasmid (pJ
lacS
) propagated in
Sulfolobus acidocaldarius
. The resulting Lac
−
mutants also grew faster than the Lac
+
parent, thereby amplifying the impact of the frequent
lacS
mutations on the population. We developed a mutant accumulation assay and corrections for the effects of copy number and differential growth for this system; the resulting measurements and calculations yielded a corrected rate of 5.1 × 10
−4
mutational events at the
lacS
gene per plasmid replication. Analysis of independent
lacS
mutants revealed three types of mutations: (i) G·C-to-A·T transitions, (ii) slipped-strand events, and (iii) deletions. These mutations were frequent in plasmid-borne
lacS
expressed at a high level but not in single-copy
lacS
in the chromosome or at lower levels of expression in a plasmid. Substitution mutations arose at only two of 12 potential priming sites of the DNA primase of the pRN1 replicon, but nearly all these mutations created nonsense (chain termination) codons. The spontaneous mutation rate of plasmid-borne
lacS
was 175-fold higher under high-expression than under low-expression conditions. The results suggest that important DNA repair or replication fidelity functions are impaired or overwhelmed in pJ
lacS
, with results analogous to those of the “transcription-associated mutagenesis” seen in bacteria and eukaryotes.
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19
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Deaconescu AM, Artsimovitch I, Grigorieff N. Interplay of DNA repair with transcription: from structures to mechanisms. Trends Biochem Sci 2012; 37:543-52. [PMID: 23084398 DOI: 10.1016/j.tibs.2012.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/10/2012] [Accepted: 09/14/2012] [Indexed: 01/29/2023]
Abstract
Many DNA transactions are crucial for maintaining genomic integrity and faithful transfer of genetic information but remain poorly understood. An example is the interplay between nucleotide excision repair (NER) and transcription, also known as transcription-coupled DNA repair (TCR). Discovered decades ago, the mechanisms for TCR have remained elusive, not in small part due to the scarcity of structural studies of key players. Here we summarize recent structural information on NER/TCR factors, focusing on bacterial systems, and integrate it with existing genetic, biochemical, and biophysical data to delineate the mechanisms at play. We also review emerging, alternative modalities for recruitment of NER proteins to DNA lesions.
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Affiliation(s)
- Alexandra M Deaconescu
- Howard Hughes Medical Institute, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 415 South St., MS 029, Waltham, MA 02454, USA.
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20
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Sakofsky CJ, Runck LA, Grogan DW. Sulfolobus mutants, generated via PCR products, which lack putative enzymes of UV photoproduct repair. ARCHAEA (VANCOUVER, B.C.) 2011; 2011:864015. [PMID: 21785574 PMCID: PMC3139894 DOI: 10.1155/2011/864015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 03/29/2011] [Indexed: 11/18/2022]
Abstract
In order to determine the biological relevance of two S. acidocaldarius proteins to the repair of UV photoproducts, the corresponding genes (Saci_1227 and Saci_1096) were disrupted, and the phenotypes of the resulting mutants were examined by various genetic assays. The disruption used integration by homologous recombination of a functional but heterologous pyrE gene, promoted by short sequences attached to both ends via PCR. The phenotypic analyses of the disruptants confirmed that ORF Saci_1227 encodes a DNA photolyase which functions in vivo, but they could not implicate ORF Saci_1096 in repair of UV- or other externally induced DNA damage despite its similarity to genes encoding UV damage endonucleases. The success of the gene-disruption strategy, which used 5' extensions of PCR primers to target cassette integration, suggests potential advantages for routine construction of Sulfolobus strains.
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Affiliation(s)
- Cynthia J. Sakofsky
- Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Clifton Court, Cincinnati, OH 45221-0006, USA
| | - Laura A. Runck
- Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Clifton Court, Cincinnati, OH 45221-0006, USA
| | - Dennis W. Grogan
- Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Clifton Court, Cincinnati, OH 45221-0006, USA
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21
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Survival of thermophilic and hyperthermophilic microorganisms after exposure to UV-C, ionizing radiation and desiccation. Arch Microbiol 2011; 193:797-809. [DOI: 10.1007/s00203-011-0718-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/13/2011] [Accepted: 05/18/2011] [Indexed: 12/11/2022]
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22
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Rouillon C, White MF. The evolution and mechanisms of nucleotide excision repair proteins. Res Microbiol 2010; 162:19-26. [PMID: 20863882 DOI: 10.1016/j.resmic.2010.09.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 07/26/2010] [Indexed: 10/19/2022]
Abstract
Nucleotide excision repair (NER) pathways remove a wide variety of bulky and helix-distorting lesions from DNA, and involve the coordinated action of damage detection, helicase and nuclease proteins. Most archaeal genomes encode eucaryal-type NER proteins, including the helicases XPB and XPD and nuclease XPF. These have been a valuable resource, yielding important mechanistic and structural insights relevant to human health. However, the nature of archaeal NER remains very uncertain. Here we review recent studies of archaeal NER proteins relevant to both eucaryal and archaeal NER systems and the evolution of repair pathways.
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Affiliation(s)
- Christophe Rouillon
- Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews, Fife KY169ST, UK
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23
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Hot Transcriptomics. ARCHAEA 2010; 2010:897585. [PMID: 21350598 PMCID: PMC3038420 DOI: 10.1155/2010/897585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 11/19/2010] [Accepted: 12/20/2010] [Indexed: 12/14/2022]
Abstract
DNA microarray technology allows for a quick and easy comparison of complete transcriptomes, resulting in improved molecular insight in fluctuations of gene expression. After emergence of the microarray technology about a decade ago, the technique has now matured and has become routine in many molecular biology laboratories. Numerous studies have been performed that have provided global transcription patterns of many organisms under a wide range of conditions. Initially, implementation of this high-throughput technology has lead to high expectations for ground breaking discoveries. Here an evaluation is performed of the insight that transcriptome analysis has brought about in the field of hyperthermophilic archaea. The examples that will be discussed have been selected on the basis of their impact, in terms of either biological insight or technological progress.
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24
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McRobbie AM, Carter LG, Kerou M, Liu H, McMahon SA, Johnson KA, Oke M, Naismith JH, White MF. Structural and functional characterisation of a conserved archaeal RadA paralog with antirecombinase activity. J Mol Biol 2009; 389:661-73. [PMID: 19414020 DOI: 10.1016/j.jmb.2009.04.060] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 04/20/2009] [Accepted: 04/27/2009] [Indexed: 12/25/2022]
Abstract
DNA recombinases (RecA in bacteria, Rad51 in eukarya and RadA in archaea) catalyse strand exchange between homologous DNA molecules, the central reaction of homologous recombination, and are among the most conserved DNA repair proteins known. RecA is the sole protein responsible for this reaction in bacteria, whereas there are several Rad51 paralogs that cooperate to catalyse strand exchange in eukaryotes. All archaea have at least one (and as many as four) RadA paralog, but their function remains unclear. Herein, we show that the three RadA paralogs encoded by the Sulfolobus solfataricus genome are expressed under normal growth conditions and are not UV inducible. We demonstrate that one of these proteins, Sso2452, which is representative of the large archaeal RadC subfamily of archaeal RadA paralogs, functions as an ATPase that binds tightly to single-stranded DNA. However, Sso2452 is not an active recombinase in vitro and inhibits D-loop formation by RadA. We present the high-resolution crystal structure of Sso2452, which reveals key structural differences from the canonical RecA family recombinases that may explain its functional properties. The possible roles of the archaeal RadA paralogs in vivo are discussed.
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Affiliation(s)
- Anne-Marie McRobbie
- Centre for Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK
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25
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Abstract
Mechanisms involved in DNA repair and genome maintenance are essential for all organisms on Earth and have been studied intensively in bacteria and eukaryotes. Their analysis in extremely thermophilic archaea offers the opportunity to discover strategies for maintaining genome integrity of the relatively little explored third domain of life, thereby shedding light on the diversity and evolution of these central and important systems. These studies might also reveal special adaptations that are essential for life at high temperature. A number of investigations of the hyperthermophilic and acidophilic crenarchaeote Sulfolobus solfataricus have been performed in recent years. Mostly, the reactions to DNA damage caused by UV light have been analysed. Whole-genome transcriptomics have demonstrated that a UV-specific response in S. solfataricus does not involve the transcriptional induction of DNA-repair genes and it is therefore different from the well-known SOS response in bacteria. Nevertheless, the UV response in S. solfataricus is impressively complex and involves many different levels of action, some of which have been elucidated and shed light on novel strategies for DNA repair, while others involve proteins of unknown function whose actions in the cell remain to be elucidated. The present review summarizes and discusses recent investigations on the UV response of S. solfataricus on both the molecular biological and the cellular levels.
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26
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Fröls S, Ajon M, Wagner M, Teichmann D, Zolghadr B, Folea M, Boekema EJ, Driessen AJM, Schleper C, Albers SV. UV-inducible cellular aggregation of the hyperthermophilic archaeon Sulfolobus solfataricus is mediated by pili formation. Mol Microbiol 2008; 70:938-52. [DOI: 10.1111/j.1365-2958.2008.06459.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Richards JD, Cubeddu L, Roberts J, Liu H, White MF. The archaeal XPB protein is a ssDNA-dependent ATPase with a novel partner. J Mol Biol 2007; 376:634-44. [PMID: 18177890 DOI: 10.1016/j.jmb.2007.12.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 12/07/2007] [Accepted: 12/10/2007] [Indexed: 12/28/2022]
Abstract
XPB is a superfamily 2 helicase with a 3'-5' polarity. In eukaryotes, XPB is an integral subunit of the transcription factor TFIIH, which plays a dual role in DNA opening at RNA polymerase II promoters and in establishing the repair bubble around a DNA lesion in nucleotide excision repair. Eukaryotic XPB has only very limited helicase activity in vitro and may function as a DNA-dependent molecular switch to catalyse local distortion of DNA in transcription and repair. Most archaea have one or two homologues of the XPB protein with a presumed role in DNA repair, but only one other subunit of the TFIIH complex, the 5'-3' helicase XPD, has been identified in archaea. Here we report the biochemical characterisation of the two homologous XPB proteins from the crenarchaeon Sulfolobus solfataricus. Although both proteins are single-stranded-DNA-stimulated ATPases, neither displays any helicase activity in vitro, consistent with recent studies of eukaryotic XPB. In almost all archaeal genomes, the xpb gene lies adjacent to a conserved partner gene, and we demonstrate that these two gene products form a physical interaction in vitro. We propose the name Bax1 (Binds archaeal XPB) for this protein, which has a predicted endonuclease domain. XPB and Bax1 may collaborate in processing nucleic acid in an archaeal-specific DNA repair pathway.
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Affiliation(s)
- Jodi D Richards
- St. Andrews University, Centre for Biomolecular Sciences, North Haugh, St. Andrews, Fife KY16 9ST, UK
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28
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Fröls S, Gordon PMK, Panlilio MA, Duggin IG, Bell SD, Sensen CW, Schleper C. Response of the hyperthermophilic archaeon Sulfolobus solfataricus to UV damage. J Bacteriol 2007; 189:8708-18. [PMID: 17905990 PMCID: PMC2168930 DOI: 10.1128/jb.01016-07] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to characterize the genome-wide transcriptional response of the hyperthermophilic, aerobic crenarchaeote Sulfolobus solfataricus to UV damage, we used high-density DNA microarrays which covered 3,368 genetic features encoded on the host genome, as well as the genes of several extrachromosomal genetic elements. While no significant up-regulation of genes potentially involved in direct DNA damage reversal was observed, a specific transcriptional UV response involving 55 genes could be dissected. Although flow cytometry showed only modest perturbation of the cell cycle, strong modulation of the transcript levels of the Cdc6 replication initiator genes was observed. Up-regulation of an operon encoding Mre11 and Rad50 homologs pointed to induction of recombinational repair. Consistent with this, DNA double-strand breaks were observed between 2 and 8 h after UV treatment, possibly resulting from replication fork collapse at damaged DNA sites. The strong transcriptional induction of genes which potentially encode functions for pilus formation suggested that conjugational activity might lead to enhanced exchange of genetic material. In support of this, a statistical microscopic analysis demonstrated that large cell aggregates formed upon UV exposure. Together, this provided supporting evidence to a link between recombinational repair and conjugation events.
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Affiliation(s)
- Sabrina Fröls
- Center of Geobiology, Dept. Biology, Jahnebakken 5, N-5020 Bergen, Norway
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29
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Götz D, Paytubi S, Munro S, Lundgren M, Bernander R, White MF. Responses of hyperthermophilic crenarchaea to UV irradiation. Genome Biol 2007; 8:R220. [PMID: 17931420 PMCID: PMC2246294 DOI: 10.1186/gb-2007-8-10-r220] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 08/09/2007] [Accepted: 10/11/2007] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND DNA damage leads to cellular responses that include the increased expression of DNA repair genes, repression of DNA replication and alterations in cellular metabolism. Archaeal information processing pathways resemble those in eukaryotes, but archaeal damage response pathways remain poorly understood. RESULTS We analyzed the transcriptional response to UV irradiation in two related crenarchaea, Sulfolobus solfataricus and Sulfolobus acidocaldarius. Sulfolobus species encounter high levels of DNA damage in nature, as they inhabit high temperature, aerobic environments and are exposed to sunlight. No increase in expression of DNA repair genes following UV irradiation was observed. There was, however, a clear transcriptional response, including repression of DNA replication and chromatin proteins. Differential effects on the expression of the three transcription factor B (tfb) genes hint at a mechanism for the modulation of transcriptional patterns in response to DNA damage. TFB3, which is strongly induced following UV irradiation, competes with TFB1 for binding to RNA polymerase in vitro, and may act as a repressor of transcription or an alternative transcription factor for certain promoters. CONCLUSION A clear response to DNA damage was observed, with down-regulation of the DNA replication machinery, changes in transcriptional regulatory proteins, and up-regulation of the biosynthetic enzymes for beta-carotene, which has UV protective properties, and proteins that detoxify reactive oxygen species. However, unlike eukaryotes and bacteria, there was no induction of DNA repair proteins in response to DNA damage, probably because these are expressed constitutively to deal with increased damage arising due to high growth temperatures.
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Affiliation(s)
- Dorothee Götz
- Aquapharm Bio-Discoveries, European Centre for Marine Biotechnology, Dunbeg, Oban PA37 1QA, UK
| | - Sonia Paytubi
- Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Stacey Munro
- Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Magnus Lundgren
- Department of Molecular Evolution, Uppsala University, Norbyvägen 18C, SE-752 36, Uppsala, Sweden
| | - Rolf Bernander
- Department of Molecular Evolution, Uppsala University, Norbyvägen 18C, SE-752 36, Uppsala, Sweden
| | - Malcolm F White
- Department of Molecular Evolution, Uppsala University, Norbyvägen 18C, SE-752 36, Uppsala, Sweden
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