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Patil S, Kondabagil K. Coevolutionary and Phylogenetic Analysis of Mimiviral Replication Machinery Suggest the Cellular Origin of Mimiviruses. Mol Biol Evol 2021; 38:2014-2029. [PMID: 33570580 PMCID: PMC8097291 DOI: 10.1093/molbev/msab003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mimivirus is one of the most complex and largest viruses known. The origin and evolution of Mimivirus and other giant viruses have been a subject of intense study in the last two decades. The two prevailing hypotheses on the origin of Mimivirus and other viruses are the reduction hypothesis, which posits that viruses emerged from modern unicellular organisms; whereas the virus-first hypothesis proposes viruses as relics of precellular forms of life. In this study, to gain insights into the origin of Mimivirus, we have carried out extensive phylogenetic, correlation, and multidimensional scaling analyses of the putative proteins involved in the replication of its 1.2-Mb large genome. Correlation analysis and multidimensional scaling methods were validated using bacteriophage, bacteria, archaea, and eukaryotic replication proteins before applying to Mimivirus. We show that a large fraction of mimiviral replication proteins, including polymerase B, clamp, and clamp loaders are of eukaryotic origin and are coevolving. Although phylogenetic analysis places some components along the lineages of phage and bacteria, we show that all the replication-related genes have been homogenized and are under purifying selection. Collectively our analysis supports the idea that Mimivirus originated from a complex cellular ancestor. We hypothesize that Mimivirus has largely retained complex replication machinery reminiscent of its progenitor while losing most of the other genes related to processes such as metabolism and translation.
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Affiliation(s)
- Supriya Patil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
| | - Kiran Kondabagil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
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2
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Szafran MJ, Strzałka A, Jakimowicz D. A highly processive actinobacterial topoisomerase I - thoughts on Streptomyces' demand for an enzyme with a unique C-terminal domain. MICROBIOLOGY-SGM 2019; 166:120-128. [PMID: 31390324 PMCID: PMC7398561 DOI: 10.1099/mic.0.000841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Topoisomerase I (TopA) is an essential enzyme that is required to remove excess negative supercoils from chromosomal DNA. Actinobacteria encode unusual TopA homologues with a unique C-terminal domain that contains lysine repeats and confers high enzyme processivity. Interestingly, the longest stretch of lysine repeats was identified in TopA from Streptomyces, environmental bacteria that undergo complex differentiation and produce a plethora of secondary metabolites. In this review, we aim to discuss potential advantages of the lysine repeats in Streptomyces TopA. We speculate that the chromosome organization, transcriptional regulation and lifestyle of these species demand a highly processive but also fine-tuneable relaxase. We hypothesize that the unique TopA provides flexible control of chromosomal topology and globally regulates gene expression.
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Affiliation(s)
- Marcin J Szafran
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Agnieszka Strzałka
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Dagmara Jakimowicz
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
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3
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Reed B, Yakovleva L, Shuman S, Ghose R. Characterization of DNA Binding by the Isolated N-Terminal Domain of Vaccinia Virus DNA Topoisomerase IB. Biochemistry 2017; 56:3307-3317. [PMID: 28570045 DOI: 10.1021/acs.biochem.7b00042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vaccinia TopIB (vTopIB), a 314-amino acid eukaryal-type IB topoisomerase, recognizes and transesterifies at the DNA sequence 5'-(T/C)CCTT↓, leading to the formation of a covalent DNA-(3'-phosphotyrosyl274)-enzyme intermediate in the supercoil relaxation reaction. The C-terminal segment of vTopIB (amino acids 81-314), which engages the DNA minor groove at the scissile phosphodiester, comprises an autonomous catalytic domain that retains cleavage specificity, albeit with a cleavage site affinity lower than that of the full-length enzyme. The N-terminal domain (amino acids 1-80) engages the major groove on the DNA face opposite the scissile phosphodiester. Whereas DNA contacts of the N-terminal domain have been implicated in the DNA site affinity of vTopIB, it was not known whether the N-terminal domain per se could bind DNA. Here, using isothermal titration calorimetry, we demonstrate the ability of the isolated N-terminal domain to bind a CCCTT-containing 24-mer duplex with an apparent affinity that is ∼2.2-fold higher than that for an otherwise identical duplex in which the pentapyrimidine sequence is changed to ACGTG. Analyses of the interactions of the isolated N-terminal domain with duplex DNA via solution nuclear magnetic resonance methods are consistent with its DNA contacts observed in DNA-bound crystal structures of full-length vTopIB. The chemical shift perturbations and changes in hydrodynamic properties triggered by CCCTT DNA versus non-CCCTT DNA suggest differences in DNA binding dynamics. The importance of key N-terminal domain contacts in the context of full-length vTopIB is underscored by assessing the effects of double-alanine mutations on DNA transesterification and its sensitivity to ionic strength.
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Affiliation(s)
- Benjamin Reed
- Department of Chemistry and Biochemistry, The City College of New York , New York, New York 10031, United States
| | - Lyudmila Yakovleva
- Molecular Biology Program, Sloan-Kettering Institute , New York, New York 10021, United States
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute , New York, New York 10021, United States
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York , New York, New York 10031, United States
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4
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Goto-Ito S, Yamagata A, Takahashi TS, Sato Y, Fukai S. Structural basis of the interaction between Topoisomerase IIIβ and the TDRD3 auxiliary factor. Sci Rep 2017; 7:42123. [PMID: 28176834 PMCID: PMC5296760 DOI: 10.1038/srep42123] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/03/2017] [Indexed: 11/09/2022] Open
Abstract
Topoisomerase IIIβ (TOP3β) is a DNA/RNA topoisomerase that has been implicated in epigenetic or translational control of gene expression. In cells, TOP3β co-exists with its specific auxiliary factor, TDRD3. TDRD3 serves as a scaffold protein to recruit TOP3β to its DNA/RNA substrates accumulating in specific cellular sites such as methylated chromatins or neural stress granules. Here we report the crystal structures of the catalytic domain of TOP3β, the DUF1767–OB-fold domains of TDRD3 and their complex at 3.44 Å, 1.62 Å and 3.6 Å resolutions, respectively. The toroidal-shaped catalytic domain of TOP3β binds the OB-fold domain of TDRD3. The TDRD3 OB-fold domain harbors the insertion loop, which is protruding from the core structure. Both the insertion loop and core region interact with TOP3β. Our pull-down binding assays showed that hydrophobic characters of the core surface and the amino- and carboxy-terminal regions of the insertion loop are essential for the interaction. Furthermore, by comparison with the structure of the homologous Topoisomerase IIIα (TOP3α)–RMI1 complex, we identified Arg96, Val109, Phe139 and the short insertion loop of TDRD3 as the critical structural elements for the specific interaction with TOP3β to avoid the non-cognate interaction with TOP3α.
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Affiliation(s)
- Sakurako Goto-Ito
- Structural Biology Laboratory, Structural Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.,CREST, JST, Saitama 332-0012, Japan
| | - Atsushi Yamagata
- Structural Biology Laboratory, Structural Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.,CREST, JST, Saitama 332-0012, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan
| | - Tomio S Takahashi
- Structural Biology Laboratory, Structural Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.,CREST, JST, Saitama 332-0012, Japan
| | - Yusuke Sato
- Structural Biology Laboratory, Structural Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.,CREST, JST, Saitama 332-0012, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan
| | - Shuya Fukai
- Structural Biology Laboratory, Structural Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.,CREST, JST, Saitama 332-0012, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan
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5
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Dahmane N, Gadelle D, Delmas S, Criscuolo A, Eberhard S, Desnoues N, Collin S, Zhang H, Pommier Y, Forterre P, Sezonov G. topIb, a phylogenetic hallmark gene of Thaumarchaeota encodes a functional eukaryote-like topoisomerase IB. Nucleic Acids Res 2016; 44:2795-805. [PMID: 26908651 PMCID: PMC4824112 DOI: 10.1093/nar/gkw097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 02/08/2016] [Indexed: 11/28/2022] Open
Abstract
Type IB DNA topoisomerases can eliminate torsional stresses produced during replication and transcription. These enzymes are found in all eukaryotes and a short version is present in some bacteria and viruses. Among prokaryotes, the long eukaryotic version is only observed in archaea of the phylum Thaumarchaeota. However, the activities and the roles of these topoisomerases have remained an open question. Here, we demonstrate that all available thaumarchaeal genomes contain a topoisomerase IB gene that defines a monophyletic group closely related to the eukaryotic enzymes. We show that the topIB gene is expressed in the model thaumarchaeon Nitrososphaera viennensis and we purified the recombinant enzyme from the uncultivated thaumarchaeon Candidatus Caldiarchaeum subterraneum. This enzyme is active in vitro at high temperature, making it the first thermophilic topoisomerase IB characterized so far. We have compared this archaeal type IB enzyme to its human mitochondrial and nuclear counterparts. The archaeal enzyme relaxes both negatively and positively supercoiled DNA like the eukaryotic enzymes. However, its pattern of DNA cleavage specificity is different and it is resistant to camptothecins (CPTs) and non-CPT Top1 inhibitors, LMP744 and lamellarin D. This newly described thermostable topoisomerases IB should be a promising new model for evolutionary, mechanistic and structural studies.
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Affiliation(s)
- Narimane Dahmane
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris-Seine (IBPS), Unité Evolution Paris-Seine (UMR 7138), F-75005 Paris, France
| | - Danièle Gadelle
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ.Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Stéphane Delmas
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris-Seine (IBPS), Unité Evolution Paris-Seine (UMR 7138), F-75005 Paris, France
| | - Alexis Criscuolo
- Hub Bioinformatique et Biostatistique - C3BI, USR 3756 IP CNRS, Institut Pasteur, 25-28, rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Stephan Eberhard
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris-Seine (IBPS), Unité Evolution Paris-Seine (UMR 7138), F-75005 Paris, France
| | - Nicole Desnoues
- Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Département de Microbiologie, Institut Pasteur, 25-28, rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Sylvie Collin
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris-Seine (IBPS), Unité Evolution Paris-Seine (UMR 7138), F-75005 Paris, France
| | - Hongliang Zhang
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, USA
| | - Yves Pommier
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, USA
| | - Patrick Forterre
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ.Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Département de Microbiologie, Institut Pasteur, 25-28, rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Guennadi Sezonov
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris-Seine (IBPS), Unité Evolution Paris-Seine (UMR 7138), F-75005 Paris, France
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6
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Abergel C, Legendre M, Claverie JM. The rapidly expanding universe of giant viruses: Mimivirus, Pandoravirus, Pithovirus and Mollivirus. FEMS Microbiol Rev 2015; 39:779-96. [PMID: 26391910 DOI: 10.1093/femsre/fuv037] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2015] [Indexed: 12/31/2022] Open
Abstract
More than a century ago, the term 'virus' was introduced to describe infectious agents that are invisible by light microscopy and capable of passing through sterilizing filters. In addition to their extremely small size, most viruses have minimal genomes and gene contents, and rely almost entirely on host cell-encoded functions to multiply. Unexpectedly, four different families of eukaryotic 'giant viruses' have been discovered over the past 10 years with genome sizes, gene contents and particle dimensions overlapping with that of cellular microbes. Their ongoing analyses are challenging accepted ideas about the diversity, evolution and origin of DNA viruses.
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Affiliation(s)
- Chantal Abergel
- Structural and Genomic Information Laboratory, UMR 7256 (IMM FR 3479) Centre National de la Recherche Scientifique & Aix-Marseille University, 13288 Marseille, France
| | - Matthieu Legendre
- Structural and Genomic Information Laboratory, UMR 7256 (IMM FR 3479) Centre National de la Recherche Scientifique & Aix-Marseille University, 13288 Marseille, France
| | - Jean-Michel Claverie
- Structural and Genomic Information Laboratory, UMR 7256 (IMM FR 3479) Centre National de la Recherche Scientifique & Aix-Marseille University, 13288 Marseille, France Assistance Publique des Hôpitaux de Marseille, La Timone, 13005 Marseille, France
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7
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Abstract
ABSTRACT In the past decade knowledge about Megaviruses, also denoted as nucleocytoplasmic large DNA viruses (NCLDVs) has been growing quickly. In the current paper, we present a general description of NCLDVs including their genome size, gene functions and homologies to other forms of life and viruses. Evolution of giant viruses from the fourth domain of life (now extinct) and a genomic complexification from smaller DNA viruses are described. Undeniable is the fact that Megaviruses in terms of their size and genomic capacity belong in between cellular and viral worlds breaking several ‘viral dogmas.’ The host range of NCLDVs goes far beyond unicellular organisms and a major challenge in the future is to establish their pathogenicity in human population.
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8
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Forterre P. Introduction and Historical Perspective. CANCER DRUG DISCOVERY AND DEVELOPMENT 2012. [DOI: 10.1007/978-1-4614-0323-4_1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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9
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Luther KB, Hülsmeier AJ, Schegg B, Deuber SA, Raoult D, Hennet T. Mimivirus collagen is modified by bifunctional lysyl hydroxylase and glycosyltransferase enzyme. J Biol Chem 2011; 286:43701-43709. [PMID: 22045808 DOI: 10.1074/jbc.m111.309096] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Collagens, the most abundant proteins in animals, are modified by hydroxylation of proline and lysine residues and by glycosylation of hydroxylysine. Dedicated prolyl hydroxylase, lysyl hydroxylase, and collagen glycosyltransferase enzymes localized in the endoplasmic reticulum mediate these modifications prior to the formation of the collagen triple helix. Whereas collagen-like proteins have been described in some fungi, bacteria, and viruses, the post-translational machinery modifying collagens has never been described outside of animals. We demonstrate that the L230 open reading frame of the giant virus Acanthamoeba polyphaga mimivirus encodes an enzyme that has distinct lysyl hydroxylase and collagen glycosyltransferase domains. We show that mimivirus L230 is capable of hydroxylating lysine and glycosylating the resulting hydroxylysine residues in a native mimivirus collagen acceptor substrate. Whereas in animals from sponges to humans the transfer of galactose to hydroxylysine in collagen is conserved, the mimivirus L230 enzyme transfers glucose to hydroxylysine, thereby defining a novel type of collagen glycosylation in nature. The presence of hydroxylysine in mimivirus proteins was confirmed by amino acid analysis of mimivirus recovered from A. polyphaga cultures. This work shows for the first time that collagen post-translational modifications are not confined to the domains of life. The utilization of glucose instead of the galactose found throughout animals as well as a bifunctional enzyme rather than two separate enzymes may represent a parallel evolutionary track in collagen biology. These results suggest that giant viruses may have contributed to the evolution of collagen biology.
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Affiliation(s)
- Kelvin B Luther
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Andreas J Hülsmeier
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Belinda Schegg
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Stefan A Deuber
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Didier Raoult
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, CNRS Unité Mixte de Recherche Institut de Recherche pour le Développement 6236, Faculté de Médecine, Université de la Méditerranée, 13385 Marseille cedex 5, France
| | - Thierry Hennet
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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10
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Yamada T. Giant viruses in the environment: their origins and evolution. Curr Opin Virol 2011; 1:58-62. [PMID: 22440568 DOI: 10.1016/j.coviro.2011.05.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 05/16/2011] [Accepted: 05/16/2011] [Indexed: 10/18/2022]
Abstract
The recent identification of giant viruses has raised important questions, not only regarding their origin and evolution, but also regarding the differentiation between viruses and living organisms. These viruses possess large genomes encoding genes potentially involved in various metabolic processes and even protein synthesis, indicating their putative autonomy. Giant viruses of the Phycodnaviridae and Mimiviridae families appear to share a common evolutionary ancestor with members of the nucleo-cytoplasmic large DNA viruses. Many giant viruses are associated with protists in aquatic environments and might have evolved in protist cells. They may therefore play important roles in material cycling in natural ecosystems. With the advent of environmental metagenomic projects, there will be more chances to encounter novel giant viruses in the future.
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Affiliation(s)
- Takashi Yamada
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
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11
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Nagarajan G, Swami SK, Dahiya SS, Sivakumar G, Narnaware SD, Tuteja FC, Patil NV. Sequence analysis of topoisomerase gene of pseudocowpox virus isolates from camels (Camelus dromedarius). Virus Res 2011; 158:277-80. [PMID: 21501639 DOI: 10.1016/j.virusres.2011.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/20/2011] [Accepted: 03/22/2011] [Indexed: 11/19/2022]
Abstract
Topoisomerase gene of pseudocowposvirus from Indian dromedarian camel was amplified by PCR using the primers of PCPV from Finnish reindeer and cloned into pGEM-T for sequence analysis. Analysis of amino acid identity revealed that Indian PCPV of camel shared 95.9-96.8 with PCPV of reindeer, 96.2-96.5 with ORFV and 87.5 with BPSV.
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Affiliation(s)
- G Nagarajan
- National Research Centre on Camel, Post Bag No. 7, Jorbeer, Bikaner 334 001, Rajasthan, India.
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12
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Giant virus with a remarkable complement of genes infects marine zooplankton. Proc Natl Acad Sci U S A 2010; 107:19508-13. [PMID: 20974979 DOI: 10.1073/pnas.1007615107] [Citation(s) in RCA: 243] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
As major consumers of heterotrophic bacteria and phytoplankton, microzooplankton are a critical link in aquatic foodwebs. Here, we show that a major marine microflagellate grazer is infected by a giant virus, Cafeteria roenbergensis virus (CroV), which has the largest genome of any described marine virus (≈730 kb of double-stranded DNA). The central 618-kb coding part of this AT-rich genome contains 544 predicted protein-coding genes; putative early and late promoter motifs have been detected and assigned to 191 and 72 of them, respectively, and at least 274 genes were expressed during infection. The diverse coding potential of CroV includes predicted translation factors, DNA repair enzymes such as DNA mismatch repair protein MutS and two photolyases, multiple ubiquitin pathway components, four intein elements, and 22 tRNAs. Many genes including isoleucyl-tRNA synthetase, eIF-2γ, and an Elp3-like histone acetyltransferase are usually not found in viruses. We also discovered a 38-kb genomic region of putative bacterial origin, which encodes several predicted carbohydrate metabolizing enzymes, including an entire pathway for the biosynthesis of 3-deoxy-d-manno-octulosonate, a key component of the outer membrane in Gram-negative bacteria. Phylogenetic analysis indicates that CroV is a nucleocytoplasmic large DNA virus, with Acanthamoeba polyphaga mimivirus as its closest relative, although less than one-third of the genes of CroV have homologs in Mimivirus. CroV is a highly complex marine virus and the only virus studied in genetic detail that infects one of the major groups of predators in the oceans.
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13
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Patel A, Yakovleva L, Shuman S, Mondragón A. Crystal structure of a bacterial topoisomerase IB in complex with DNA reveals a secondary DNA binding site. Structure 2010; 18:725-33. [PMID: 20541510 PMCID: PMC2886027 DOI: 10.1016/j.str.2010.03.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 03/11/2010] [Accepted: 03/25/2010] [Indexed: 11/21/2022]
Abstract
Type IB DNA topoisomerases (TopIB) are monomeric enzymes that relax supercoils by cleaving and resealing one strand of duplex DNA within a protein clamp that embraces a approximately 21 DNA segment. A longstanding conundrum concerns the capacity of TopIB enzymes to stabilize intramolecular duplex DNA crossovers and form protein-DNA synaptic filaments. Here we report a structure of Deinococcus radiodurans TopIB in complex with a 12 bp duplex DNA that demonstrates a secondary DNA binding site located on the surface of the C-terminal domain. It comprises a distinctive interface with one strand of the DNA duplex and is conserved in all TopIB enzymes. Modeling of a TopIB with both DNA sites suggests that the secondary site could account for DNA crossover binding, nucleation of DNA synapsis, and generation of a filamentous plectoneme. Mutations of the secondary site eliminate synaptic plectoneme formation without affecting DNA cleavage or supercoil relaxation.
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Affiliation(s)
- Asmita Patel
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, 2205 Tech Drive, Evanston, Illinois 60208
| | - Lyudmila Yakovleva
- Molecular Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, New York 10065
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, New York 10065
| | - Alfonso Mondragón
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, 2205 Tech Drive, Evanston, Illinois 60208
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14
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Perry K, Hwang Y, Bushman FD, Van Duyne GD. Insights from the structure of a smallpox virus topoisomerase-DNA transition state mimic. Structure 2010; 18:127-37. [PMID: 20152159 PMCID: PMC2822398 DOI: 10.1016/j.str.2009.10.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 09/30/2009] [Accepted: 10/30/2009] [Indexed: 11/24/2022]
Abstract
Poxviruses encode their own type IB topoisomerases (TopIBs), which release superhelical tension generated by replication and transcription of their genomes. To investigate the reaction catalyzed by viral TopIBs, we have determined the structure of a variola virus topoisomerase-DNA complex trapped as a vanadate transition state mimic. The structure reveals how the viral TopIB enzymes are likely to position the DNA duplex for ligation following relaxation of supercoils and identifies the sources of friction observed in single-molecule experiments that argue against free rotation. The structure also identifies a conformational change in the leaving group sugar that must occur prior to cleavage and reveals a mechanism for promoting ligation following relaxation of supercoils that involves an Asp-minor groove interaction. Overall, the new structural data support a common catalytic mechanism for the TopIB superfamily but indicate distinct methods for controlling duplex rotation in the small versus large enzyme subfamilies.
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Affiliation(s)
- Kay Perry
- Department of Biochemistry and Biophysics and Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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15
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Yutin N, Koonin EV. Evolution of DNA ligases of nucleo-cytoplasmic large DNA viruses of eukaryotes: a case of hidden complexity. Biol Direct 2009; 4:51. [PMID: 20021668 PMCID: PMC2806865 DOI: 10.1186/1745-6150-4-51] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 12/18/2009] [Indexed: 11/10/2022] Open
Abstract
Background Eukaryotic Nucleo-Cytoplasmic Large DNA Viruses (NCLDV) encode most if not all of the enzymes involved in their DNA replication. It has been inferred that genes for these enzymes were already present in the last common ancestor of the NCLDV. However, the details of the evolution of these genes that bear on the complexity of the putative ancestral NCLDV and on the evolutionary relationships between viruses and their hosts are not well understood. Results Phylogenetic analysis of the ATP-dependent and NAD-dependent DNA ligases encoded by the NCLDV reveals an unexpectedly complex evolutionary history. The NAD-dependent ligases are encoded only by a minority of NCLDV (including mimiviruses, some iridoviruses and entomopoxviruses) but phylogenetic analysis clearly indicated that all viral NAD-dependent ligases are monophyletic. Combined with the topology of the NCLDV tree derived by consensus of trees for universally conserved genes suggests that this enzyme was represented in the ancestral NCLDV. Phylogenetic analysis of ATP-dependent ligases that are encoded by chordopoxviruses, most of the phycodnaviruses and Marseillevirus failed to demonstrate monophyly and instead revealed an unexpectedly complex evolutionary trajectory. The ligases of the majority of phycodnaviruses and Marseillevirus seem to have evolved from bacteriophage or bacterial homologs; the ligase of one phycodnavirus, Emiliana huxlei virus, belongs to the eukaryotic DNA ligase I branch; and ligases of chordopoxviruses unequivocally cluster with eukaryotic DNA ligase III. Conclusions Examination of phyletic patterns and phylogenetic analysis of DNA ligases of the NCLDV suggest that the common ancestor of the extant NCLDV encoded an NAD-dependent ligase that most likely was acquired from a bacteriophage at the early stages of evolution of eukaryotes. By contrast, ATP-dependent ligases from different prokaryotic and eukaryotic sources displaced the ancestral NAD-dependent ligase at different stages of subsequent evolution. These findings emphasize complex routes of viral evolution that become apparent through detailed phylogenomic analysis but not necessarily in reconstructions based on phyletic patterns of genes. Reviewers This article was reviewed by: Patrick Forterre, George V. Shpakovski, and Igor B. Zhulin.
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Affiliation(s)
- Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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Abstract
Mimivirus, a virus infecting amoebae of the acanthamoeba genus, is the prototype member of the Mimiviridae, the latest addition to the family of the nucleocytoplasmic large DNA viruses, already including the Poxviridae, the Iridoviridae, the Asfarviridae, and the Phycodnaviridae. Because of the size of its particle-a fiber-covered icosahedral protein capsid 0.75 microm in diameter-Mimivirus was initially mistaken for a parasitic bacterium. Its 1.2-Mb genome sequence encodes more than 900 proteins, many of them associated with functions never before encountered in a virus, such as four aminoacyl-tRNA synthetases. These findings revived the debate about the origin of DNA viruses and their possible role in the emergence of the eukaryotic nucleus. The recent isolation of a new type of satellite virus, called a virophage, associated with a second strain of Mimivirus, confirmed its unique position within the virus world. Post-genomic studies are now in progress, slowly shedding some light on the physiology of the most complex virus isolated to date.
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Affiliation(s)
- Jean-Michel Claverie
- Structural and Genomic Information Laboratory, CNRS-UPR 2589, IFR-88, Aix-Marseille University, Parc Scientifique de Luminy, Case 934, FR-13288 Marseille, France.
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17
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Byrne D, Grzela R, Lartigue A, Audic S, Chenivesse S, Encinas S, Claverie JM, Abergel C. The polyadenylation site of Mimivirus transcripts obeys a stringent 'hairpin rule'. Genome Res 2009; 19:1233-42. [PMID: 19403753 DOI: 10.1101/gr.091561.109] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mimivirus, a giant DNA virus infecting Acanthamoeba, is revealing an increasing list of unique features such as a 1.2-Mb genome with numerous genes not found in other viruses, a uniquely conserved promoter signal, and a particle of unmatched complexity using two distinct portals for genome delivery and packaging. Herein, we contribute a further Mimivirus distinctive feature discovered by sequencing a panel of viral cDNAs produced for probing the structure of Mimivirus transcripts. All Mimivirus mRNAs are polyadenylated at a site coinciding exactly with unrelated, but strongly palindromic, genomic sequences. The analysis of 454 Life Sciences (Roche) FLX cDNA tags (150,651) confirmed this finding for all Mimivirus genes independent of their transcription timings and expression levels. The absence of a suitable palindromic signal between adjacent genes results in transcripts encompassing multiple ORFs in the same or even in opposite orientations. Surprisingly, Mimivirus tRNAs are expressed as polyadenylated messengers, including an ORF/tRNA composite mRNA. To our knowledge, both the nature and the stringency of the "hairpin rule" defining the location of polyadenylation sites are unique, raising once more the question of Mimivirus's evolutionary origin. The precise molecular mechanisms implementing the hairpin rule into the 3'-end processing of Mimivirus pre-mRNAs remain to be elucidated.
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Affiliation(s)
- Deborah Byrne
- Structural and Genomic Information Laboratory, CNRS-UPR 2589, IFR-88, Aix-Marseille University, Parc Scientifique de Luminy, Case 934, 13288 Marseille Cedex 9, France
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18
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Forterre P, Gadelle D. Phylogenomics of DNA topoisomerases: their origin and putative roles in the emergence of modern organisms. Nucleic Acids Res 2009; 37:679-92. [PMID: 19208647 PMCID: PMC2647321 DOI: 10.1093/nar/gkp032] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Topoisomerases are essential enzymes that solve topological problems arising from the double-helical structure of DNA. As a consequence, one should have naively expected to find homologous topoisomerases in all cellular organisms, dating back to their last common ancestor. However, as observed for other enzymes working with DNA, this is not the case. Phylogenomics analyses indicate that different sets of topoisomerases were present in the most recent common ancestors of each of the three cellular domains of life (some of them being common to two or three domains), whereas other topoisomerases families or subfamilies were acquired in a particular domain, or even a particular lineage, by horizontal gene transfers. Interestingly, two groups of viruses encode topoisomerases that are only distantly related to their cellular counterparts. To explain these observations, we suggest that topoisomerases originated in an ancestral virosphere, and that various subfamilies were later on transferred independently to different ancient cellular lineages. We also proposed that topoisomerases have played a critical role in the origin of modern genomes and in the emergence of the three cellular domains.
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Affiliation(s)
- Patrick Forterre
- Institut de Génétique et Microbiologie, Univ Paris-Sud, 91405 Orsay Cedex, France
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19
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Brochier-Armanet C, Gribaldo S, Forterre P. A DNA topoisomerase IB in Thaumarchaeota testifies for the presence of this enzyme in the last common ancestor of Archaea and Eucarya. Biol Direct 2008; 3:54. [PMID: 19105819 PMCID: PMC2621148 DOI: 10.1186/1745-6150-3-54] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Accepted: 12/23/2008] [Indexed: 01/08/2023] Open
Abstract
DNA topoisomerase IB (TopoIB) was thought for a long time to be a eukaryotic specific enzyme. A shorter version was then found in viruses and later on in several bacteria, but not in archaea. Here, we show that a eukaryotic-like TopoIB is present in the recently sequenced genomes of two archaea of the newly proposed phylum Thaumarchaeota. Phylogenetic analyses suggest that a TopoIB was present in the last common ancestor of Archaea and Eucarya. This finding indicates that the last common ancestor of Archaea and Eucarya may have harboured a DNA genome.
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Affiliation(s)
- Céline Brochier-Armanet
- Laboratoire de Chimie Bactérienne, Université de Provence, Aix-Marseille I, CNRS UPR9043, IFR88, Marseille, France.
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20
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Filée J, Pouget N, Chandler M. Phylogenetic evidence for extensive lateral acquisition of cellular genes by Nucleocytoplasmic large DNA viruses. BMC Evol Biol 2008; 8:320. [PMID: 19036122 PMCID: PMC2607284 DOI: 10.1186/1471-2148-8-320] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Accepted: 11/26/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Nucleo-Cytoplasmic Large DNA viruses (NCLDV), a diverse group that infects a wide range of eukaryotic hosts, exhibit a large heterogeneity in genome size (between 100 kb and 1.2 Mb) but have been suggested to form a monophyletic group on the basis of a small subset of approximately 30 conserved genes. NCLDV were proposed to have evolved by simplification from cellular organism although some of the giant NCLDV have clearly grown by gene accretion from a bacterial origin. RESULTS We demonstrate here that many NCLDV lineages appear to have undergone frequent gene exchange in two different ways. Viruses which infect protists directly (Mimivirus) or algae which exist as intracellular protists symbionts (Phycodnaviruses) acquire genes from a bacterial source. Metazoan viruses such as the Poxviruses show a predominant acquisition of host genes. In both cases, the laterally acquired genes show a strong tendency to be positioned at the tip of the genome. Surprisingly, several core genes believed to be ancestral in the family appear to have undergone lateral gene transfers, suggesting that the NCLDV ancestor might have had a smaller genome than previously believed. Moreover, our data show that the larger the genome, the higher is the number of laterally acquired genes. This pattern is incompatible with a genome reduction from a cellular ancestor. CONCLUSION We propose that the NCLDV viruses have evolved by significant growth of a simple DNA virus by gene acquisition from cellular sources.
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Affiliation(s)
- Jonathan Filée
- Laboratoire de Microbiologie et Génétique Moléculaires, CNRS Campus Toulouse III, 118 Route de Narbonne, F-31062 Toulouse Cedex, France.
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21
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Abstract
DNA topoisomerases are a diverse set of essential enzymes responsible for maintaining chromosomes in an appropriate topological state. Although they vary considerably in structure and mechanism, the partnership between topoisomerases and DNA has engendered commonalities in how these enzymes engage nucleic acid substrates and control DNA strand manipulations. All topoisomerases can harness the free energy stored in supercoiled DNA to drive their reactions; some further use the energy of ATP to alter the topology of DNA away from an enzyme-free equilibrium ground state. In the cell, topoisomerases regulate DNA supercoiling and unlink tangled nucleic acid strands to actively maintain chromosomes in a topological state commensurate with particular replicative and transcriptional needs. To carry out these reactions, topoisomerases rely on dynamic macromolecular contacts that alternate between associated and dissociated states throughout the catalytic cycle. In this review, we describe how structural and biochemical studies have furthered our understanding of DNA topoisomerases, with an emphasis on how these complex molecular machines use interfacial interactions to harness and constrain the energy required to manage DNA topology.
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22
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Characterization of a trifunctional mimivirus mRNA capping enzyme and crystal structure of the RNA triphosphatase domain. Structure 2008; 16:501-12. [PMID: 18400173 DOI: 10.1016/j.str.2008.01.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 01/02/2008] [Accepted: 01/03/2008] [Indexed: 01/26/2023]
Abstract
The RNA triphosphatase (RTPase) components of the mRNA capping apparatus are a bellwether of eukaryal taxonomy. Fungal and protozoal RTPases belong to the triphosphate tunnel metalloenzyme (TTM) family, exemplified by yeast Cet1. Several large DNA viruses encode metal-dependent RTPases unrelated to the cysteinyl-phosphatase RTPases of their metazoan host organisms. The origins of DNA virus RTPases are unclear because they are structurally uncharacterized. Mimivirus, a giant virus of amoeba, resembles poxviruses in having a trifunctional capping enzyme composed of a metal-dependent RTPase module fused to guanylyltransferase (GTase) and guanine-N7 methyltransferase domains. The crystal structure of mimivirus RTPase reveals a minimized tunnel fold and an active site strikingly similar to that of Cet1. Unlike homodimeric fungal RTPases, mimivirus RTPase is a monomer. The mimivirus TTM-type RTPase-GTase fusion resembles the capping enzymes of amoebae, providing evidence that the ancestral large DNA virus acquired its capping enzyme from a unicellular host.
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23
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Yakovleva L, Chen S, Hecht SM, Shuman S. Chemical and traditional mutagenesis of vaccinia DNA topoisomerase provides insights to cleavage site recognition and transesterification chemistry. J Biol Chem 2008; 283:16093-103. [PMID: 18367446 DOI: 10.1074/jbc.m801595200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Vaccinia DNA topoisomerase IB (TopIB) relaxes supercoils by forming and resealing a covalent DNA-(3'-phosphotyrosyl)-enzyme intermediate. Here we gained new insights to the TopIB mechanism through "chemical mutagenesis." Meta-substituted analogs of Tyr(274) were introduced by in vitro translation in the presence of a chemically misacylated tRNA. We report that a meta-OH reduced the rate of DNA cleavage 130-fold without affecting the rate of religation. By contrast, meta-OCH(3) and NO(2) groups elicited only a 6-fold decrement in cleavage rate. We propose that the meta-OH uniquely suppresses deprotonation of the para-OH nucleophile during the cleavage step. Assembly of the vaccinia TopIB active site is triggered by protein contacts with a specific DNA sequence 5'-C(+5)C(+4)C(+3)T(+2)T(+1)p downward arrowN (where downward arrow denotes the cleavage site). A signature alpha-helix of the poxvirus TopIB ((132)GKMKYLKENETVG(144)) engages the target site in the major groove and thereby recruits catalytic residue Arg(130) to the active site. The effects of 11 missense mutations at Tyr(136) highlight the importance of van der Waals interactions with the 3'-G(+4)pG(+3)p dinucleotide of the nonscissile strand for DNA cleavage and supercoil relaxation. Asn(140) and Thr(142) donate hydrogen bonds to the pro-(S(p))-oxygen of the G(+3)pA(+2) phosphodiester of the nonscissile strand. Lys(133) and Lys(135) interact with purine nucleobases in the major groove. Whereas none of these side chains is essential per se, an N140A/T142A double mutation reduces the rate of supercoil relaxation and DNA cleavage by 120- and 30-fold, respectively, and a K133A/K135A double mutation slows relaxation and cleavage by 120- and 35-fold, respectively. These results underscore functional redundancy at the TopIB-DNA interface.
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Affiliation(s)
- Lyudmila Yakovleva
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
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24
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Raoult D, La Scola B, Birtles R. The discovery and characterization of Mimivirus, the largest known virus and putative pneumonia agent. Clin Infect Dis 2007; 45:95-102. [PMID: 17554709 DOI: 10.1086/518608] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Accepted: 03/05/2007] [Indexed: 11/03/2022] Open
Abstract
During recent years, the usefulness of amoebal co-cultures as an alternative means of isolating and cultivating fastidious microorganisms has been increasingly recognized. While characterizing a collection of bacteria that had been isolated using this approach, we encountered an organism that, on preliminary analysis, appeared to be a gram-positive coccus. However, additional examination revealed that it was not a bacterium but rather, surprisingly, a virus. The dimensions of the virus particle (diameter, 0.8 microm) and its genome size (1.2 Mb) are far more akin to those of bacteria than to those of previously recognized viruses. These characteristics, together with such features as the breadth and complexity of its gene content, challenge the current definition of a "virus." Furthermore, the virus, now named "Mimivirus," has been implicated as an agent of pneumonia in humans and, thus, should be considered a putative emerging pathogen.
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Affiliation(s)
- Didier Raoult
- Unité des Rickettsies, Faculté de Médecine, Université de la Méditerrannée, Marseille, France.
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25
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Minkah N, Hwang Y, Perry K, Van Duyne GD, Hendrickson R, Lefkowitz EJ, Hannenhalli S, Bushman FD. Variola virus topoisomerase: DNA cleavage specificity and distribution of sites in Poxvirus genomes. Virology 2007; 365:60-9. [PMID: 17462694 PMCID: PMC2705903 DOI: 10.1016/j.virol.2007.02.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 01/10/2007] [Accepted: 02/24/2007] [Indexed: 11/16/2022]
Abstract
Topoisomerase enzymes regulate superhelical tension in DNA resulting from transcription, replication, repair, and other molecular transactions. Poxviruses encode an unusual type IB topoisomerase that acts only at conserved DNA sequences containing the core pentanucleotide 5'-(T/C)CCTT-3'. In X-ray structures of the variola virus topoisomerase bound to DNA, protein-DNA contacts were found to extend beyond the core pentanucleotide, indicating that the full recognition site has not yet been fully defined in functional studies. Here we report quantitation of DNA cleavage rates for an optimized 13 bp site and for all possible single base substitutions (40 total sites), with the goals of understanding the molecular mechanism of recognition and mapping topoisomerase sites in poxvirus genome sequences. The data allow a precise definition of enzyme-DNA interactions and the energetic contributions of each. We then used the resulting "action matrix" to show that favorable topoisomerase sites are distributed all along the length of poxvirus DNA sequences, consistent with a requirement for local release of superhelical tension in constrained topological domains. In orthopox genomes, an additional central cluster of sites was also evident. A negative correlation of predicted topoisomerase sites was seen relative to early terminators, but no correlation was seen with early or late promoters. These data define the full variola virus topoisomerase recognition site and provide a new window on topoisomerase function in vivo.
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Affiliation(s)
- Nana Minkah
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6076, USA
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26
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Forterre P, Gribaldo S, Gadelle D, Serre MC. Origin and evolution of DNA topoisomerases. Biochimie 2007; 89:427-46. [PMID: 17293019 DOI: 10.1016/j.biochi.2006.12.009] [Citation(s) in RCA: 248] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 12/12/2006] [Indexed: 12/28/2022]
Abstract
The DNA topoisomerases are essential for DNA replication, transcription, recombination, as well as for chromosome compaction and segregation. They may have appeared early during the formation of the modern DNA world. Several families and subfamilies of the two types of DNA topoisomerases (I and II) have been described in the three cellular domains of life (Archaea, Bacteria and Eukarya), as well as in viruses infecting eukaryotes or bacteria. The main families of DNA topoisomerases, Topo IA, Topo IB, Topo IC (Topo V), Topo IIA and Topo IIB (Topo VI) are not homologous, indicating that they originated independently. However, some of them share homologous modules or subunits that were probably recruited independently to produce different topoisomerase activities. The puzzling phylogenetic distribution of the various DNA topoisomerase families and subfamilies cannot be easily reconciled with the classical models of early evolution describing the relationships between the three cellular domains. A possible scenario is based on a Last Universal Common Ancestor (LUCA) with a RNA genome (i.e. without the need for DNA topoisomerases). Different families of DNA topoisomerases (some of them possibly of viral origin) would then have been independently introduced in the different cellular domains. We review here the main characteristics of the different families and subfamilies of DNA topoisomerases in a historical and evolutionary perspective, with the hope to stimulate further works and discussions on the origin and evolution of these fascinating enzymes.
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Affiliation(s)
- Patrick Forterre
- Institut de Génétique et Microbiologie, UMR8621, Université Paris-Sud 11, Bat. 400-409, 91405 Orsay Cedex, France
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27
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Filée J, Siguier P, Chandler M. I am what I eat and I eat what I am: acquisition of bacterial genes by giant viruses. Trends Genet 2006; 23:10-5. [PMID: 17109990 DOI: 10.1016/j.tig.2006.11.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 10/06/2006] [Accepted: 11/02/2006] [Indexed: 11/22/2022]
Abstract
Giant viruses are nucleocytoplasmic large DNA viruses (NCLDVs) that infect algae (phycodnaviruses) and amoebae (Mimivirus). We report an unexpected abundance in these giant viruses of islands of bacterial-type genes, including apparently intact prokaryotic mobile genetic elements, and hypothesize that NCLDV genomes undergo successive accretions of bacterial genes. The viruses could acquire bacterial genes within their bacteria-feeding eukaryotic hosts, and we suggest that such acquisition is driven by the intimate coupling of recombination and replication in NCLDVs.
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Affiliation(s)
- Jonathan Filée
- Laboratoire de Microbiologie et Génétique Moléculaires, CNRS 118, Route de Narbonne, F-31062 Toulouse Cedex, France.
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28
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Tian L, Shuman S. Vaccinia topoisomerase mutants illuminate roles for Phe59, Gly73, Gln69 and Phe215. Virology 2006; 359:466-76. [PMID: 17059840 DOI: 10.1016/j.virol.2006.08.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 08/23/2006] [Accepted: 08/29/2006] [Indexed: 11/22/2022]
Abstract
Vaccinia topoisomerase provides a model system for structure-function analysis of the type IB topoisomerase family. Here we performed an alanine scan of eight positions in the beta4 and beta5 strands of the N-terminal domain (Leu57, Ile58, Phe59, Val60, Gly61, Ser62, Gln69 and Gly73) and eight positions in the alpha8-alpha9 loop of the C-terminal catalytic domain (Ser241, Ile242, Ser243, Pro244, Leu245, Pro246, Ser247, and Pro248). Mutants F59A, G73A, and Q69A displayed rate defects in relaxing supercoiled DNA that were attributed to effects on DNA binding rather than transesterification chemistry. Replacing Gln69 conservatively with Asn, Glu or Lys failed to restore relaxation activity. Gln69 is located along a concave DNA-binding surface of the N-terminal domain and it makes direct contact with the +2A base of the 5'-CCCTT/3-GGGAA target site for DNA cleavage. Gly73 is located at the junction between the N-terminal domain and catalytic domain and it is likely to act as a swivel for the large domain movements that coordinate DNA ingress and closure of the topoisomerase clamp around the duplex. Previous alanine scanning had identified Phe215 in helix alpha7 of the catalytic domain as contributing to DNA relaxation activity. Here we find that F215L resembles F215A in its diminished relaxation activity and its sensitivity to inhibition by salt. The Phe215 side chain makes van der Waals contacts to Ile98, Met121 and Phe101, which we propose stabilize a three helix bundle and promote clamp closure.
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Affiliation(s)
- Ligeng Tian
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10021, USA
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29
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Renesto P, Abergel C, Decloquement P, Moinier D, Azza S, Ogata H, Fourquet P, Gorvel JP, Claverie JM. Mimivirus giant particles incorporate a large fraction of anonymous and unique gene products. J Virol 2006; 80:11678-85. [PMID: 16971431 PMCID: PMC1642625 DOI: 10.1128/jvi.00940-06] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Acanthamoeba polyphaga mimivirus is the largest known virus in both particle size and genome complexity. Its 1.2-Mb genome encodes 911 proteins, among which only 298 have predicted functions. The composition of purified isolated virions was analyzed by using a combined electrophoresis/mass spectrometry approach allowing the identification of 114 proteins. Besides the expected major structural components, the viral particle packages 12 proteins unambiguously associated with transcriptional machinery, 3 proteins associated with DNA repair, and 2 topoisomerases. Other main functional categories represented in the virion include oxidative pathways and protein modification. More than half of the identified virion-associated proteins correspond to anonymous genes of unknown function, including 45 "ORFans." As demonstrated by both Western blotting and immunogold staining, some of these "ORFans," which lack any convincing similarity in the sequence databases, are endowed with antigenic properties. Thus, anonymous and unique genes constituting the majority of the mimivirus gene complement encode bona fide proteins that are likely to participate in well-integrated processes.
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Affiliation(s)
- Patricia Renesto
- Unité des Rickettsies, CNRS UMR 6020, IFR-48, Faculté de Médecine, 27 Boulevard Jean Moulin, 13385 Marseille, France.
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30
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Benarroch D, Shuman S. Characterization of mimivirus NAD+-dependent DNA ligase. Virology 2006; 353:133-43. [PMID: 16844179 DOI: 10.1016/j.virol.2006.04.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 04/06/2006] [Accepted: 04/07/2006] [Indexed: 10/24/2022]
Abstract
Mimivirus, a parasite of Acanthamoeba polyphaga, is the largest DNA virus known; it encodes a cornucopia of proteins with imputed functions in DNA replication, modification, and repair. Here we produced, purified, and characterized mimivirus DNA ligase (MimiLIG), an NAD+-dependent nick joining enzyme homologous to bacterial LigA and entomopoxvirus DNA ligase. MimiLIG is a 636-aa polypeptide composed of an N-terminal NAD+ specificity module (domain Ia), linked to nucleotidyltransferase, OB-fold, helix-hairpin-helix, and BRCT domains, but it lacks the tetracysteine Zn-binding module found in all bacterial LigA enzymes. MimiLIG requires conserved domain Ia residues Tyr36, Asp46, Tyr49, and Asp50 for its initial reaction with NAD+ to form the ligase-AMP intermediate, but not for the third step of phosphodiester formation at a preadenylylated nick. MimiLIG differs from bacterial LigA enzymes in that its activity is strongly dependent on the C-terminal BRCT domain, deletion of which reduced its specific activity in nick joining by 75-fold without affecting the ligase adenylylation step. The DeltaBRCT mutant of MimiLIG was impaired in sealing at a preadenylylated nick. We propose that eukaryal DNA viruses acquired the NAD+-dependent ligases by horizontal transfer from a bacterium and that MimiLIG predates entomopoxvirus ligase, which lacks both the tetracysteine and BRCT domains. We speculate that the dissemination of NAD+-dependent ligase from bacterium to eukaryotic virus might have occurred within an amoebal host.
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Affiliation(s)
- Delphine Benarroch
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10021, USA
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31
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Claverie JM, Ogata H, Audic S, Abergel C, Suhre K, Fournier PE. Mimivirus and the emerging concept of "giant" virus. Virus Res 2006; 117:133-44. [PMID: 16469402 DOI: 10.1016/j.virusres.2006.01.008] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Revised: 01/06/2006] [Accepted: 01/09/2006] [Indexed: 11/15/2022]
Abstract
The recently discovered Acanthamoeba polyphaga Mimivirus is the largest known DNA virus. Its particle size (750 nm), genome length (1.2 million bp) and large gene repertoire (911 protein coding genes) blur the established boundaries between viruses and parasitic cellular organisms. In addition, the analysis of its genome sequence identified many types of genes never before encountered in a virus, including aminoacyl-tRNA synthetases and other central components of the translation machinery previously thought to be the signature of cellular organisms. In this article, we examine how the finding of such a giant virus might durably influence the way we look at microbial biodiversity, and lead us to revise the classification of microbial domains and life forms. We propose to introduce the word "girus" to recognize the intermediate status of these giant DNA viruses, the genome complexity of which makes them closer to small parasitic prokaryotes than to regular viruses.
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Affiliation(s)
- Jean-Michel Claverie
- Information Génomique et Structurale, CNRS UPR 2589, IBSM, Parc Scientifique de Luminy, 163 Avenue de Luminy, Case 934, 13288 Marseille Cedex 9, France.
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Patel A, Shuman S, Mondragón A. Crystal structure of a bacterial type IB DNA topoisomerase reveals a preassembled active site in the absence of DNA. J Biol Chem 2005; 281:6030-7. [PMID: 16368685 DOI: 10.1074/jbc.m512332200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Type IB DNA topoisomerases are found in all eukarya, two families of eukaryotic viruses (poxviruses and mimivirus), and many genera of bacteria. They alter DNA topology by cleaving and resealing one strand of duplex DNA via a covalent DNA-(3-phosphotyrosyl)-enzyme intermediate. Bacterial type IB enzymes were discovered recently and are described as poxvirus-like with respect to their small size, primary structures, and bipartite domain organization. Here we report the 1.75-A crystal structure of Deinococcus radiodurans topoisomerase IB (DraTopIB), a prototype of the bacterial clade. DraTopIB consists of an amino-terminal (N) beta-sheet domain (amino acids 1-90) and a predominantly alpha-helical carboxyl-terminal (C) domain (amino acids 91-346) that closely resemble the corresponding domains of vaccinia virus topoisomerase IB. The five amino acids of DraTopIB that comprise the catalytic pentad (Arg-137, Lys-174, Arg-239, Asn-280, and Tyr-289) are preassembled into the active site in the absence of DNA in a manner nearly identical to the pentad configuration in human topoisomerase I bound to DNA. This contrasts with the apoenzyme of vaccinia topoisomerase, in which three of the active site constituents are either displaced or disordered. The N and C domains of DraTopIB are splayed apart in an "open" conformation, in which the surface of the catalytic domain containing the active site is exposed for DNA binding. A comparison with the human topoisomerase I-DNA cocrystal structure suggests how viral and bacterial topoisomerase IB enzymes might bind DNA circumferentially via movement of the N domain into the major groove and clamping of a disordered loop of the C domain around the helix.
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Affiliation(s)
- Asmita Patel
- Department of Biochemistry, Molecular and Cell Biology, Northwestern University, 2205 Tech Drive, Evanston, IL 60208, USA
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