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Yin J, Liu Y, He D, Li P, Qiao M, Luo H, Qu X, Mei S, Wu Y, Sun Y, Gan F, Tang B, Tang XF. A TrmBL2-like transcription factor mediates the growth phase-dependent expression of halolysin SptA in a concentration-dependent manner in Natrinema gari J7-2. Appl Environ Microbiol 2024; 90:e0074124. [PMID: 38953660 PMCID: PMC11267917 DOI: 10.1128/aem.00741-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/08/2024] [Indexed: 07/04/2024] Open
Abstract
To cope with a high-salinity environment, haloarchaea generally employ the twin-arginine translocation (Tat) pathway to transport secretory proteins across the cytoplasm membrane in a folded state, including Tat-dependent extracellular subtilases (halolysins) capable of autocatalytic activation. Some halolysins, such as SptA of Natrinema gari J7-2, are produced at late-log phase to prevent premature enzyme activation and proteolytic damage of cellular proteins in haloarchaea; however, the regulation mechanism for growth phase-dependent expression of halolysins remains largely unknown. In this study, a DNA-protein pull-down assay was performed to identify the proteins binding to the 5'-flanking sequence of sptA encoding halolysin SptA in strain J7-2, revealing a TrmBL2-like transcription factor (NgTrmBL2). The ΔtrmBL2 mutant of strain J7-2 showed a sharp decrease in the production of SptA, suggesting that NgTrmBL2 positively regulates sptA expression. The purified recombinant NgTrmBL2 mainly existed as a dimer although monomeric and higher-order oligomeric forms were detected by native-PAGE analysis. The results of electrophoretic mobility shift assays (EMSAs) showed that NgTrmBL2 binds to the 5'-flanking sequence of sptA in a non-specific and concentration-dependent manner and exhibits an increased DNA-binding affinity with the increase in KCl concentration. Moreover, we found that a distal cis-regulatory element embedded in the neighboring upstream gene negatively regulates trmBL2 expression and thus participates in the growth phase-dependent biosynthesis of halolysin SptA. IMPORTANCE Extracellular proteases play important roles in nutrient metabolism, processing of functional proteins, and antagonism of haloarchaea, but no transcription factor involved in regulating the expression of haloaechaeal extracellular protease has been reported yet. Here we report that a TrmBL2-like transcription factor (NgTrmBL2) mediates the growth phase-dependent expression of an extracellular protease, halolysin SptA, of haloarchaeon Natrinema gari J7-2. In contrast to its hyperthermophilic archaeal homologs, which are generally considered to be global transcription repressors, NgTrmBL2 functions as a positive regulator for sptA expression. This study provides new clues about the transcriptional regulation mechanism of extracellular protease in haloarchaea and the functional diversity of archaeal TrmBL2.
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Affiliation(s)
- Jing Yin
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yang Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Dan He
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Ping Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Mengting Qiao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Hongyi Luo
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiaoyi Qu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Sha Mei
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yi Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yiqi Sun
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Fei Gan
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Wuhan, China
| | - Bing Tang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Wuhan, China
| | - Xiao-Feng Tang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Wuhan, China
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Yutin N, Mutz P, Krupovic M, Koonin EV. Mriyaviruses: small relatives of giant viruses. mBio 2024; 15:e0103524. [PMID: 38832788 PMCID: PMC11253617 DOI: 10.1128/mbio.01035-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 05/01/2024] [Indexed: 06/05/2024] Open
Abstract
The phylum Nucleocytoviricota consists of large and giant viruses that range in genome size from about 100 kilobases (kb) to more than 2.5 megabases. Here, using metagenome mining followed by extensive phylogenomic analysis and protein structure comparison, we delineate a distinct group of viruses with double-stranded (ds) DNA genomes in the range of 35-45 kb that appear to be related to the Nucleocytoviricota. In phylogenetic trees of the conserved double jelly-roll major capsid proteins (MCPs) and DNA packaging ATPases, these viruses do not show affinity to any particular branch of the Nucleocytoviricota and accordingly would comprise a class which we propose to name "Mriyaviricetes" (after Ukrainian "mriya," dream). Structural comparison of the MCP suggests that, among the extant virus lineages, mriyaviruses are the closest one to the ancestor of the Nucleocytoviricota. In the phylogenetic trees, mriyaviruses split into two well-separated branches, the family Yaraviridae and proposed new family "Gamadviridae." The previously characterized members of these families, yaravirus and Pleurochrysis sp. endemic viruses, infect amoeba and haptophytes, respectively. The genomes of the rest of the mriyaviruses were assembled from metagenomes from diverse environments, suggesting that mriyaviruses infect various unicellular eukaryotes. Mriyaviruses lack DNA polymerase, which is encoded by all other members of the Nucleocytoviricota, and RNA polymerase subunits encoded by all cytoplasmic viruses among the Nucleocytoviricota, suggesting that they replicate in the host cell nuclei. All mriyaviruses encode a HUH superfamily endonuclease that is likely to be essential for the initiation of virus DNA replication via the rolling circle mechanism. IMPORTANCE The origin of giant viruses of eukaryotes that belong to the phylum Nucleocytoviricota is not thoroughly understood and remains a matter of major interest and debate. Here, we combine metagenome database searches with extensive protein sequence and structure analysis to describe a distinct group of viruses with comparatively small genomes of 35-45 kilobases that appear to comprise a distinct class within the phylum Nucleocytoviricota that we provisionally named "Mriyaviricetes." Mriyaviruses appear to be the closest identified relatives of the ancestors of the Nucleocytoviricota. Analysis of proteins encoded in mriyavirus genomes suggests that they replicate their genome via the rolling circle mechanism that is unusual among viruses with double-stranded DNA genomes and so far not described for members of Nucleocytoviricota.
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Affiliation(s)
- Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland, USA
| | - Pascal Mutz
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland, USA
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, Archaeal Virology Unit, Paris, France
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland, USA
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3
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Yutin N, Mutz P, Krupovic M, Koonin EV. Mriyaviruses: Small Relatives of Giant Viruses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582850. [PMID: 38529486 PMCID: PMC10962738 DOI: 10.1101/2024.02.29.582850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
The phylum Nucleocytoviricota consists of large and giant viruses that range in genome size from about 100 kilobases (kb) to more than 2.5 megabases. Here, using metagenome mining followed by extensive phylogenomic analysis and protein structure comparison, we delineate a distinct group of viruses with double-stranded (ds) DNA genomes in the range of 35-45 kb that appear to be related to the Nucleocytoviricota. In phylogenetic trees of the conserved double jelly-roll major capsid proteins (MCP) and DNA packaging ATPases, these viruses do not show affinity to any particular branch of the Nucleocytoviricota and accordingly would comprise a class which we propose to name "Mriyaviricetes" (after Ukrainian Mriya, dream). Structural comparison of the MCP suggests that, among the extant virus lineages, mriyaviruses are the closest one to the ancestor of the Nucleocytoviricota. In the phylogenetic trees, mriyaviruses split into two well-separated branches, the family Yaraviridae and proposed new family "Gamadviridae". The previously characterized members of these families, Yaravirus and Pleurochrysis sp. endemic viruses, infect amoeba and haptophytes, respectively. The genomes of the rest of the mriyaviruses were assembled from metagenomes from diverse environments, suggesting that mriyaviruses infect various unicellular eukaryotes. Mriyaviruses lack DNA polymerase, which is encoded by all other members of the Nucleocytoviricota, and RNA polymerase subunits encoded by all cytoplasmic viruses among the Nucleocytoviricota, suggesting that they replicate in the host cell nuclei. All mriyaviruses encode a HUH superfamily endonuclease that is likely to be essential for the initiation of virus DNA replication via the rolling circle mechanism.
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Affiliation(s)
- Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Pascal Mutz
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, Archaeal Virology Unit, Paris 75015, France
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
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4
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Wu Y, Zhang J, Wang B, Zhang Y, Li H, Liu Y, Yin J, He D, Luo H, Gan F, Tang B, Tang XF. Dissecting the Arginine and Lysine Biosynthetic Pathways and Their Relationship in Haloarchaeon Natrinema gari J7-2 via Endogenous CRISPR-Cas System-Based Genome Editing. Microbiol Spectr 2023; 11:e0028823. [PMID: 37347159 PMCID: PMC10433800 DOI: 10.1128/spectrum.00288-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/07/2023] [Indexed: 06/23/2023] Open
Abstract
The evolutionary relationship between arginine and lysine biosynthetic pathways has been well established in bacteria and hyperthermophilic archaea but remains largely unknown in haloarchaea. Here, the endogenous CRISPR-Cas system was harnessed to edit arginine and lysine biosynthesis-related genes in the haloarchaeon Natrinema gari J7-2. The ΔargW, ΔargX, ΔargB, and ΔargD mutant strains display an arginine auxotrophic phenotype, while the ΔdapB mutant shows a lysine auxotrophic phenotype, suggesting that strain J7-2 utilizes the ArgW-mediated pathway and the diaminopimelate (DAP) pathway to synthesize arginine and lysine, respectively. Unlike the ArgD in Escherichia coli acting as a bifunctional aminotransferase in both the arginine biosynthesis pathway and the DAP pathway, the ArgD in strain J7-2 participates only in arginine biosynthesis. Meanwhile, in strain J7-2, the function of argB cannot be compensated for by its evolutionary counterpart ask in the DAP pathway. Moreover, strain J7-2 cannot utilize α-aminoadipate (AAA) to synthesize lysine via the ArgW-mediated pathway, in contrast to hyperthermophilic archaea that employ a bifunctional LysW-mediated pathway to synthesize arginine (or ornithine) and lysine from glutamate and AAA, respectively. Additionally, the replacement of a 5-amino-acid signature motif responsible for substrate specificity of strain J7-2 ArgX with that of its hyperthermophilic archaeal homologs cannot endow the ΔdapB mutant with the ability to biosynthesize lysine from AAA. The in vitro analysis shows that strain J7-2 ArgX acts on glutamate rather than AAA. These results suggest that the arginine and lysine biosynthetic pathways of strain J7-2 are highly specialized during evolution. IMPORTANCE Due to their roles in amino acid metabolism and close evolutionary relationship, arginine and lysine biosynthetic pathways represent interesting models for probing functional specialization of metabolic routes. The current knowledge with respect to arginine and lysine biosynthesis is limited for haloarchaea compared to that for bacteria and hyperthermophilic archaea. Our results demonstrate that the haloarchaeon Natrinema gari J7-2 employs the ArgW-mediated pathway and the DAP pathway for arginine and lysine biosynthesis, respectively, and the two pathways are functionally independent of each other; meanwhile, ArgX is a key determinant of substrate specificity of the ArgW-mediated pathway in strain J7-2. This study provides new clues about haloarchaeal amino acid metabolism and confirms the convenience and efficiency of endogenous CRISPR-Cas system-based genome editing in haloarchaea.
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Affiliation(s)
- Yi Wu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jia Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Bingxue Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yanyan Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Huai Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yang Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jing Yin
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Dan He
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Hongyi Luo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Fei Gan
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Wuhan, China
| | - Bing Tang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Wuhan, China
| | - Xiao-Feng Tang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Wuhan, China
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5
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Gehlert FO, Weidenbach K, Barüske B, Hallack D, Repnik U, Schmitz RA. Newly Established Genetic System for Functional Analysis of MetSV. Int J Mol Sci 2023; 24:11163. [PMID: 37446343 DOI: 10.3390/ijms241311163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
The linear chromosome of the Methanosarcina spherical virus with 10,567 bp exhibits 22 ORFs with mostly unknown functions. Annotation using common tools and databases predicted functions for a few genes like the type B DNA polymerase (MetSVORF07) or the small (MetSVORF15) and major (MetSVORF16) capsid proteins. For verification of assigned functions of additional ORFs, biochemical or genetic approaches were found to be essential. Consequently, we established a genetic system for MetSV by cloning its genome into the E. coli plasmid pCR-XL-2. Comparisons of candidate plasmids with the MetSV reference based on Nanopore sequencing revealed several mutations of yet unknown provenance with an impact on protein-coding sequences. Linear MetSV inserts were generated by BamHI restriction, purified and transformed in Methanosarcina mazei by an optimized liposome-mediated transformation protocol. Analysis of resulting MetSV virions by TEM imaging and infection experiments demonstrated no significant differences between plasmid-born viruses and native MetSV particles regarding their morphology or lytic behavior. The functionality of the genetic system was tested by the generation of a ΔMetSVORF09 mutant that was still infectious. Our genetic system of MetSV, the first functional system for a virus of methanoarchaea, now allows us to obtain deeper insights into MetSV protein functions and virus-host interactions.
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Affiliation(s)
- Finn O Gehlert
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Katrin Weidenbach
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Brian Barüske
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Daniela Hallack
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Urska Repnik
- Central Microscopy, Christian Albrechts University, 24118 Kiel, Germany
| | - Ruth A Schmitz
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
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6
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Liu Y, Du S, Chen X, Dyall-Smith M, Jalasvuori M, Oksanen HM. ICTV Virus Taxonomy Profile: Simuloviridae 2023. J Gen Virol 2023; 104. [PMID: 37093734 DOI: 10.1099/jgv.0.001841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
The family Simuloviridae includes tailless icosahedral viruses with an internal lipid membrane. The capsid is constructed from two major capsid proteins, both with a single jelly-roll fold. The genome is a circular dsDNA molecule of 16-19 kb. All members infect halophilic archaea in the class Halobacteria (phylum Euryarchaeota) and are temperate viruses, their proviruses residing in host cells as extrachromosomal episomes. Once the lytic life cycle is triggered, production of virions causes cell lysis. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Simuloviridae, which is available at ictv.global/report/simuloviridae.
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Affiliation(s)
- Ying Liu
- Archaeal Virology Unit, Institut Pasteur, Université Paris Cité, CNRS UMR6047, Paris, France
| | - Shishen Du
- Department of Microbiology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
| | - Xiangdong Chen
- Department of Microbiology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
| | - Mike Dyall-Smith
- Computational Biology Group, Max Planck Institute of Biochemistry, Martinsried, Germany
- Veterinary Biosciences, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
| | - Matti Jalasvuori
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Hanna M Oksanen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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Liang J, Quan Z, Zhu J, Gan M, Shen P. A functional promoter from the archaeon Halobacterium salinarum is also transcriptionally active in E. coli. BMC Microbiol 2022; 22:79. [PMID: 35331139 PMCID: PMC8943987 DOI: 10.1186/s12866-022-02489-y] [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: 04/20/2021] [Accepted: 02/25/2022] [Indexed: 11/18/2022] Open
Abstract
Background Archaea form a third domain of life that is distinct from Bacteria and Eukarya. So far, many scholars have elucidated considerable details about the typical promoter architectures of the three domains of life. However, a functional promoter from the archaeon Halobacterium salinarum has never been studied in Escherichia coli. Results This paper found that the promoter of Halobacterium salinarum showed a promoter function in Escherichia coli. This Escherichia coli promoter structure contains − 10 box, -10 box extension and − 29 elements, however, no -35 box. The − 29 element is exercised by the TATA box in archaea. And we isolated the RM10 fragment that possessed the fusion characteristics of bacteria and archaea, which was overlapped with functionality of TATA box and − 29 elements. Conclusions The − 29 element reflects the evolutionary relationship between the archaeal promoter and the bacterial promoter. The result possibly indicated that there may be a certain internal connection between archaea and bacteria. We hypothesized that it provided a new viewpoint of the evolutionary relationship of archaea and other organisms. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02489-y.
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Affiliation(s)
- Jinye Liang
- Key laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, 410083, Changsha, China
| | - Zhenghui Quan
- College of Life Sciences, Wuhan University, 430000, Wuhan, China
| | - Jianyu Zhu
- Key laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, 410083, Changsha, China. .,College of Life Sciences, Wuhan University, 430000, Wuhan, China.
| | - Min Gan
- Key laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, 410083, Changsha, China.
| | - Ping Shen
- College of Life Sciences, Wuhan University, 430000, Wuhan, China.
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Chen B, Chen Z, Wang Y, Gong H, Sima L, Wang J, Ouyang S, Gan W, Krupovic M, Chen X, Du S. ORF4 of the Temperate Archaeal Virus SNJ1 Governs the Lysis-Lysogeny Switch and Superinfection Immunity. J Virol 2020; 94:e00841-20. [PMID: 32522850 PMCID: PMC7394903 DOI: 10.1128/jvi.00841-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/01/2020] [Indexed: 12/21/2022] Open
Abstract
Recent environmental and metagenomic studies have considerably increased the repertoire of archaeal viruses and suggested that they play important roles in nutrient cycling in the biosphere. However, very little is known about how they regulate their life cycles and interact with their hosts. Here, we report that the life cycle of the temperate haloarchaeal virus SNJ1 is controlled by the product ORF4, a small protein belonging to the antitoxin MazE superfamily. We show that ORF4 controls the lysis-lysogeny switch of SNJ1 and mediates superinfection immunity by repression of genomic DNA replication of the superinfecting viruses. Bioinformatic analysis shows that ORF4 is highly conserved in two SNJ1-like proviruses, suggesting that the mechanisms for lysis-lysogeny switch and superinfection immunity are conserved in this group of viruses. As the lysis-lysogeny switch and superinfection immunity of archaeal viruses have been poorly studied, we suggest that SNJ1 could serve as a model system to study these processes.IMPORTANCE Archaeal viruses are important parts of the virosphere. Understanding how they regulate their life cycles and interact with host cells provide crucial insights into their biological functions and the evolutionary histories of viruses. However, mechanistic studies of the life cycle of archaeal viruses are scarce due to a lack of genetic tools and demanding cultivation conditions. Here, we discover that the temperate haloarchaeal virus SNJ1, which infects Natrinema sp. strain J7, employs a lysis-lysogeny switch and establishes superinfection immunity like bacteriophages. We show that its ORF4 is critical for both processes and acts as a repressor of the replication of SNJ1. These results establish ORF4 as a master regulator of SNJ1 life cycle and provides novel insights on the regulation of life cycles by temperate archaeal viruses and on their interactions with host cells.
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Affiliation(s)
- Beibei Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Zhao Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yuchen Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Han Gong
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Linshan Sima
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jiao Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Shushan Ouyang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Wenqiang Gan
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Mart Krupovic
- Department of Microbiology, Institut Pasteur, Paris, France
| | - Xiangdong Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Shishen Du
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
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9
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Wang J, Liu Y, Liu Y, Du K, Xu S, Wang Y, Krupovic M, Chen X. A novel family of tyrosine integrases encoded by the temperate pleolipovirus SNJ2. Nucleic Acids Res 2019; 46:2521-2536. [PMID: 29361162 PMCID: PMC5861418 DOI: 10.1093/nar/gky005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/08/2018] [Indexed: 01/19/2023] Open
Abstract
Genomes of halophilic archaea typically contain multiple loci of integrated mobile genetic elements (MGEs). Despite the abundance of these elements, however, mechanisms underlying their site-specific integration and excision have not been investigated. Here, we identified and characterized a novel recombination system encoded by the temperate pleolipovirus SNJ2, which infects haloarchaeon Natrinema sp. J7-1. SNJ2 genome is inserted into the tRNAMet gene and flanked by 14 bp direct repeats corresponding to attachment core sites. We showed that SNJ2 encodes an integrase (IntSNJ2) that excises the proviral genome from its host cell chromosome, but requires two small accessory proteins, Orf2 and Orf3, for integration. These proteins were co-transcribed with IntSNJ2 to form an operon. Homology searches showed that IntSNJ2-type integrases are widespread in haloarchaeal genomes and are associated with various integrated MGEs. Importantly, we confirmed that SNJ2-like recombination systems are encoded by haloarchaea from three different genera and are critical for integration and excision. Finally, phylogenetic analysis suggested that IntSNJ2-type recombinases belong to a novel family of archaeal integrases distinct from previously characterized recombinases, including those from the archaeal SSV- and pNOB8-type families.
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Affiliation(s)
- Jiao Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yingchun Liu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Ying Liu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.,Unit of Molecular Biology of the Gene in Extremophiles, Department of Microbiology, Institut Pasteur, Paris 75015, France
| | - Kaixin Du
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shuqi Xu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yuchen Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Mart Krupovic
- Unit of Molecular Biology of the Gene in Extremophiles, Department of Microbiology, Institut Pasteur, Paris 75015, France
| | - Xiangdong Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
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10
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Xiong L, Liu S, Chen S, Xiao Y, Zhu B, Gao Y, Zhang Y, Chen B, Luo J, Deng Z, Chen X, Wang L, Chen S. A new type of DNA phosphorothioation-based antiviral system in archaea. Nat Commun 2019; 10:1688. [PMID: 30975999 PMCID: PMC6459918 DOI: 10.1038/s41467-019-09390-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/07/2019] [Indexed: 01/21/2023] Open
Abstract
Archaea and Bacteria have evolved different defence strategies that target virtually all steps of the viral life cycle. The diversified virion morphotypes and genome contents of archaeal viruses result in a highly complex array of archaea-virus interactions. However, our understanding of archaeal antiviral activities lags far behind our knowledges of those in bacteria. Here we report a new archaeal defence system that involves DndCDEA-specific DNA phosphorothioate (PT) modification and the PbeABCD-mediated halt of virus propagation via inhibition of DNA replication. In contrast to the breakage of invasive DNA by DndFGH in bacteria, DndCDEA-PbeABCD does not degrade or cleave viral DNA. The PbeABCD-mediated PT defence system is widespread and exhibits extensive interdomain and intradomain gene transfer events. Our results suggest that DndCDEA-PbeABCD is a new type of PT-based virus resistance system, expanding the known arsenal of defence systems as well as our understanding of host-virus interactions.
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Affiliation(s)
- Lei Xiong
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
- Taihe Hospital, Hubei University of Medicine, 442000, Shiyan, Hubei, China
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China
| | - Siyi Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China
| | - Si Chen
- School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, 430023, Wuhan, China
| | - Yao Xiao
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China
| | - Bochen Zhu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China
| | - Yali Gao
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China
| | - Yujing Zhang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China
| | - Beibei Chen
- College of Life Sciences, Wuhan University, 430071, Wuhan, China
| | - Jie Luo
- Taihe Hospital, Hubei University of Medicine, 442000, Shiyan, Hubei, China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
| | - Xiangdong Chen
- College of Life Sciences, Wuhan University, 430071, Wuhan, China
| | - Lianrong Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China
- Taihe Hospital, Hubei University of Medicine, 442000, Shiyan, Hubei, China
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China
| | - Shi Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, China.
- Taihe Hospital, Hubei University of Medicine, 442000, Shiyan, Hubei, China.
- Brain Center, Zhongnan Hospital, Wuhan University, 430071, Wuhan, China.
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11
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Heringer P, Kuhn GCS. Exploring the Remote Ties between Helitron Transposases and Other Rolling-Circle Replication Proteins. Int J Mol Sci 2018; 19:E3079. [PMID: 30304800 PMCID: PMC6213432 DOI: 10.3390/ijms19103079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 09/26/2018] [Accepted: 10/07/2018] [Indexed: 01/30/2023] Open
Abstract
Rolling-circle replication (RCR) elements constitute a diverse group that includes viruses, plasmids, and transposons, present in hosts from all domains of life. Eukaryotic RCR transposons, also known as Helitrons, are found in species from all eukaryotic kingdoms, sometimes representing a large portion of their genomes. Despite the impact of Helitrons on their hosts, knowledge about their relationship with other RCR elements is still elusive. Here, we compared the endonuclease domain sequence of Helitron transposases with the corresponding region from RCR proteins found in a wide variety of mobile genetic elements. To do that, we used a stepwise alignment approach followed by phylogenetic and multidimensional scaling analyses. Although it has been suggested that Helitrons might have originated from prokaryotic transposons or eukaryotic viruses, our results indicate that Helitron transposases share more similarities with proteins from prokaryotic viruses and plasmids instead. We also provide evidence for the division of RCR endonucleases into three groups (Y1, Y2, and Yx), covering the whole diversity of this protein family. Together, these results point to prokaryotic elements as the likely closest ancestors of eukaryotic RCR transposons, and further demonstrate the fluidity that characterizes the boundaries separating viruses, plasmids, and transposons.
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Affiliation(s)
- Pedro Heringer
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, CEP 31270-901, Brazil.
| | - Gustavo C S Kuhn
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, CEP 31270-901, Brazil.
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12
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Li M, Yin J, Mei S, Wang X, Tang XF, Tang B. Halolysin SptA, a Serine Protease, Contributes to Growth-Phase Transition of Haloarchaeon Natrinema sp. J7-2, and Its Expression Involves Cooperative Action of Multiple Cis-Regulatory Elements. Front Microbiol 2018; 9:1799. [PMID: 30123209 PMCID: PMC6085418 DOI: 10.3389/fmicb.2018.01799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/17/2018] [Indexed: 12/18/2022] Open
Abstract
Many haloarchaea produce extracellular subtilisin-like proteases (halolysins) during late log phase; however, the physiological function and regulatory mechanism of growth phase-dependent production of halolysins are unknown. Halolysin SptA, the major extracellular protease of Natrinema sp. J7-2, is capable of intracellular self-activation to affect haloarchaeal growth. Here, we report that deletion of sptA leads to loss of extracellular and intracellular protease activities against azocasein and/or suc-AAPF-pNA, as well as a change in growth-phase transition of the haloarchaeon. Our results suggest that SptA is important for strain J7-2 to enter the stationary and death phases. Deletion and mutational analyses of the 5'-flanking region of sptA revealed two partially overlapping, semi-palindromic sequences upstream of the TATA box act as positive and negative cis-regulatory elements, respectively, to mediate sptA expression in late log phase. Additionally, a negative cis-regulatory element covering WW motif and a distant enhancer contribute to the modulation of sptA expression. Our results demonstrate that SptA functions both extracellularly and intracellularly, and that sptA expression relies on the cooperative action of multiple cis-regulatory elements, allowing SptA to exert its function properly at different growth stages in strain J7-2.
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Affiliation(s)
- Moran Li
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jing Yin
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Sha Mei
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xuhong Wang
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiao-Feng Tang
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Wuhan, China
| | - Bing Tang
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Wuhan, China
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13
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Wang Y, Chen B, Cao M, Sima L, Prangishvili D, Chen X, Krupovic M. Rolling-circle replication initiation protein of haloarchaeal sphaerolipovirus SNJ1 is homologous to bacterial transposases of the IS91 family insertion sequences. J Gen Virol 2018; 99:416-421. [DOI: 10.1099/jgv.0.001009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Yuchen Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, PR China
| | - Beibei Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, PR China
| | - Mengzhuo Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, PR China
| | - Linshan Sima
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, PR China
| | - David Prangishvili
- Department of Microbiology, Institut Pasteur, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Paris, France
| | - Xiangdong Chen
- China Center for Type Culture Collection, Wuhan, PR China
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, PR China
| | - Mart Krupovic
- Department of Microbiology, Institut Pasteur, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Paris, France
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14
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Krupovic M, Cvirkaite-Krupovic V, Iranzo J, Prangishvili D, Koonin EV. Viruses of archaea: Structural, functional, environmental and evolutionary genomics. Virus Res 2017; 244:181-193. [PMID: 29175107 DOI: 10.1016/j.virusres.2017.11.025] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 11/18/2022]
Abstract
Viruses of archaea represent one of the most enigmatic parts of the virosphere. Most of the characterized archaeal viruses infect extremophilic hosts and display remarkable diversity of virion morphotypes, many of which have never been observed among viruses of bacteria or eukaryotes. The uniqueness of the virion morphologies is matched by the distinctiveness of the genomes of these viruses, with ∼75% of genes encoding unique proteins, refractory to functional annotation based on sequence analyses. In this review, we summarize the state-of-the-art knowledge on various aspects of archaeal virus genomics. First, we outline how structural and functional genomics efforts provided valuable insights into the functions of viral proteins and revealed intricate details of the archaeal virus-host interactions. We then highlight recent metagenomics studies, which provided a glimpse at the diversity of uncultivated viruses associated with the ubiquitous archaea in the oceans, including Thaumarchaeota, Marine Group II Euryarchaeota, and others. These findings, combined with the recent discovery that archaeal viruses mediate a rapid turnover of thaumarchaea in the deep sea ecosystems, illuminate the prominent role of these viruses in the biosphere. Finally, we discuss the origins and evolution of archaeal viruses and emphasize the evolutionary relationships between viruses and non-viral mobile genetic elements. Further exploration of the archaeal virus diversity as well as functional studies on diverse virus-host systems are bound to uncover novel, unexpected facets of the archaeal virome.
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Affiliation(s)
- Mart Krupovic
- Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, Paris, France.
| | | | - Jaime Iranzo
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, USA
| | - David Prangishvili
- Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, Paris, France
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, USA
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15
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Abstract
One of the most prominent features of archaea is the extraordinary diversity of their DNA viruses. Many archaeal viruses differ substantially in morphology from bacterial and eukaryotic viruses and represent unique virus families. The distinct nature of archaeal viruses also extends to the gene composition and architectures of their genomes and the properties of the proteins that they encode. Environmental research has revealed prominent roles of archaeal viruses in influencing microbial communities in ocean ecosystems, and recent metagenomic studies have uncovered new groups of archaeal viruses that infect extremophiles and mesophiles in diverse habitats. In this Review, we summarize recent advances in our understanding of the genomic and morphological diversity of archaeal viruses and the molecular biology of their life cycles and virus-host interactions, including interactions with archaeal CRISPR-Cas systems. We also examine the potential origins and evolution of archaeal viruses and discuss their place in the global virosphere.
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16
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Construction of Expression Shuttle Vectors for the Haloarchaeon Natrinema sp. J7 Based on Its Chromosomal Origins of Replication. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2017; 2017:4237079. [PMID: 28348508 PMCID: PMC5350488 DOI: 10.1155/2017/4237079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/28/2016] [Accepted: 12/26/2016] [Indexed: 12/11/2022]
Abstract
Haloarchaeon Natrinema sp. J7, the first reported archaeon harboring both plasmid and chromosome-based temperate viruses, is a useful model for investigating archaeal virus-host and virus-virus interactions. However, the lack of genetic tools has limited such studies. On the basis of the automatically replicating sequences of the J7 chromosome and the pyrF marker, we constructed seven vectors, six of which were confirmed to possess replication ability in a pyrF-deletion derivative of J7 (J7-F). Among these vectors, pFJ1, pFJ4, and pFJ6 could be transformed into the host strain with relatively high efficiency (approximately 103 colony-forming units/μg DNA) and were present at about one copy per chromosome. These three vectors could be stably maintained in J7-F without selection and were used for heterologous protein expression. Only pFJ6 was found to be present in the transformed cells in an exclusively episomal, nonintegrated state (one copy per chromosome). In contrast, some pFJ1 and pFJ4 DNA was probably integrated into the J7-F chromosome. In addition, pFJ6 was found to be compatible with pYCJ in J7 cells, suggesting that these two vectors could be used for further studies of virus-virus and virus-host interactions.
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17
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Bipartite Network Analysis of the Archaeal Virosphere: Evolutionary Connections between Viruses and Capsidless Mobile Elements. J Virol 2016; 90:11043-11055. [PMID: 27681128 DOI: 10.1128/jvi.01622-16] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/19/2016] [Indexed: 11/20/2022] Open
Abstract
Archaea and particularly hyperthermophilic crenarchaea are hosts to many unusual viruses with diverse virion shapes and distinct gene compositions. As is typical of viruses in general, there are no universal genes in the archaeal virosphere. Therefore, to obtain a comprehensive picture of the evolutionary relationships between viruses, network analysis methods are more productive than traditional phylogenetic approaches. Here we present a comprehensive comparative analysis of genomes and proteomes from all currently known taxonomically classified and unclassified, cultivated and uncultivated archaeal viruses. We constructed a bipartite network of archaeal viruses that includes two classes of nodes, the genomes and gene families that connect them. Dissection of this network using formal community detection methods reveals strong modularity, with 10 distinct modules and 3 putative supermodules. However, compared to similar previously analyzed networks of eukaryotic and bacterial viruses, the archaeal virus network is sparsely connected. With the exception of the tailed viruses related to bacteriophages of the order Caudovirales and the families Turriviridae and Sphaerolipoviridae that are linked to a distinct supermodule of eukaryotic and bacterial viruses, there are few connector genes shared by different archaeal virus modules. In contrast, most of these modules include, in addition to viruses, capsidless mobile elements, emphasizing tight evolutionary connections between the two types of entities in archaea. The relative contributions of distinct evolutionary origins, in particular from nonviral elements, and insufficient sampling to the sparsity of the archaeal virus network remain to be determined by further exploration of the archaeal virosphere. IMPORTANCE Viruses infecting archaea are among the most mysterious denizens of the virosphere. Many of these viruses display no genetic or even morphological relationship to viruses of bacteria and eukaryotes, raising questions regarding their origins and position in the global virosphere. Analysis of 5,740 protein sequences from 116 genomes allowed dissection of the archaeal virus network and showed that most groups of archaeal viruses are evolutionarily connected to capsidless mobile genetic elements, including various plasmids and transposons. This finding could reflect actual independent origins of the distinct groups of archaeal viruses from different nonviral elements, providing important insights into the emergence and evolution of the archaeal virome.
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