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Ledvina HE, Whiteley AT. Conservation and similarity of bacterial and eukaryotic innate immunity. Nat Rev Microbiol 2024:10.1038/s41579-024-01017-1. [PMID: 38418927 DOI: 10.1038/s41579-024-01017-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2024] [Indexed: 03/02/2024]
Abstract
Pathogens are ubiquitous and a constant threat to their hosts, which has led to the evolution of sophisticated immune systems in bacteria, archaea and eukaryotes. Bacterial immune systems encode an astoundingly large array of antiviral (antiphage) systems, and recent investigations have identified unexpected similarities between the immune systems of bacteria and animals. In this Review, we discuss advances in our understanding of the bacterial innate immune system and highlight the components, strategies and pathogen restriction mechanisms conserved between bacteria and eukaryotes. We summarize evidence for the hypothesis that components of the human immune system originated in bacteria, where they first evolved to defend against phages. Further, we discuss shared mechanisms that pathogens use to overcome host immune pathways and unexpected similarities between bacterial immune systems and interbacterial antagonism. Understanding the shared evolutionary path of immune components across domains of life and the successful strategies that organisms have arrived at to restrict their pathogens will enable future development of therapeutics that activate the human immune system for the precise treatment of disease.
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Affiliation(s)
- Hannah E Ledvina
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Aaron T Whiteley
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.
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2
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Wimmer F, Englert F, Wandera KG, Alkhnbashi O, Collins S, Backofen R, Beisel C. Interrogating two extensively self-targeting Type I CRISPR-Cas systems in Xanthomonas albilineans reveals distinct anti-CRISPR proteins that block DNA degradation. Nucleic Acids Res 2024; 52:769-783. [PMID: 38015466 PMCID: PMC10810201 DOI: 10.1093/nar/gkad1097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 11/29/2023] Open
Abstract
CRISPR-Cas systems store fragments of invader DNA as spacers to recognize and clear those same invaders in the future. Spacers can also be acquired from the host's genomic DNA, leading to lethal self-targeting. While self-targeting can be circumvented through different mechanisms, natural examples remain poorly explored. Here, we investigate extensive self-targeting by two CRISPR-Cas systems encoding 24 self-targeting spacers in the plant pathogen Xanthomonas albilineans. We show that the native I-C and I-F1 systems are actively expressed and that CRISPR RNAs are properly processed. When expressed in Escherichia coli, each Cascade complex binds its PAM-flanked DNA target to block transcription, while the addition of Cas3 paired with genome targeting induces cell killing. While exploring how X. albilineans survives self-targeting, we predicted putative anti-CRISPR proteins (Acrs) encoded within the bacterium's genome. Screening of identified candidates with cell-free transcription-translation systems and in E. coli revealed two Acrs, which we named AcrIC11 and AcrIF12Xal, that inhibit the activity of Cas3 but not Cascade of the respective system. While AcrF12Xal is homologous to AcrIF12, AcrIC11 shares sequence and structural homology with the anti-restriction protein KlcA. These findings help explain tolerance of self-targeting through two CRISPR-Cas systems and expand the known suite of DNA degradation-inhibiting Acrs.
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Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Frank Englert
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Katharina G Wandera
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Omer S Alkhnbashi
- Information and Computer Science Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
- Interdisciplinary Research Center for Intelligent Secure Systems (IRC-ISS), King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
| | - Scott P Collins
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Rolf Backofen
- Bioinformatics group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
- Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
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3
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Johnson CN, Bullen NP, Andersen SE, Arya G, Marotta SR, Whitney JC, Duerkop BA. Evolution of a small phage protein overcomes antiphage defense in Enterococcus faecalis. bioRxiv 2023:2023.11.16.567456. [PMID: 38014348 PMCID: PMC10680825 DOI: 10.1101/2023.11.16.567456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The prevalence of multidrug resistant (MDR) bacterial infections continues to rise as the development of new antibiotics needed to combat these infections remains stagnant. MDR enterococci, which are a common cause of hospital-acquired infections, are emerging as one of the major contributors to this crisis. A potential therapeutic approach for combating MDR enterococci is bacteriophage (phage) therapy, which entails the use of lytic viruses to infect and kill pathogenic bacteria. While phages that lyse some strains of MDR enterococci have been identified, other strains display high levels of phage resistance and the mechanisms underlying this resistance are unknown. Here, we use a CRISPR interference (CRISPRi) screen to identify a genetic locus found on a mobilizable plasmid from vancomycin-resistant Enterococcus faecalis involved in phage resistance. This locus encodes a putative serine recombinase followed by a Type IV restriction enzyme (TIV-RE) and we show that this enzyme is sufficient to restrict the replication of the lytic phage in E. faecalis. We further find that phages can evolve to overcome restriction by acquiring a missense mutation in a novel TIV-RE inhibitor protein encoded by many enterococcal phages. We show that this inhibitor, which we have named anti-restriction-factor A (arfA), directly binds to and inactivates diverse TIV-REs. Overall, our findings significantly advance our understanding of phage defense in drug-resistant E. faecalis and provide mechanistic insight into how phages can evolve to overcome antiphage defense systems.
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Andriianov A, Trigüis S, Drobiazko A, Sierro N, Ivanov NV, Selmer M, Severinov K, Isaev A. Phage T3 overcomes the BREX defense through SAM cleavage and inhibition of SAM synthesis by SAM lyase. Cell Rep 2023; 42:112972. [PMID: 37578860 DOI: 10.1016/j.celrep.2023.112972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/17/2023] [Accepted: 07/27/2023] [Indexed: 08/16/2023] Open
Abstract
Bacteriophage T3 encodes a SAMase that, through cleavage of S-adenosyl methionine (SAM), circumvents the SAM-dependent type I restriction-modification (R-M) defense. We show that SAMase also allows T3 to evade the BREX defense. Although SAM depletion weakly affects BREX methylation, it completely inhibits the defensive function of BREX, suggesting that SAM could be a co-factor for BREX-mediated exclusion of phage DNA, similar to its anti-defense role in type I R-M. The anti-BREX activity of T3 SAMase is mediated not just by enzymatic degradation of SAM but also by direct inhibition of MetK, the host SAM synthase. We present a 2.8 Å cryoelectron microscopy (cryo-EM) structure of the eight-subunit T3 SAMase-MetK complex. Structure-guided mutagenesis reveals that this interaction stabilizes T3 SAMase in vivo, further stimulating its anti-BREX activity. This work provides insights in the versatility of bacteriophage counterdefense mechanisms and highlights the role of SAM as a co-factor of diverse bacterial immunity systems.
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Affiliation(s)
| | - Silvia Trigüis
- Department of Cell and Molecular Biology, Uppsala University, BMC, Box 596, 751 24 Uppsala, Sweden
| | - Alena Drobiazko
- Skolkovo Institute of Science and Technology, Moscow 143028, Russia
| | - Nicolas Sierro
- Philip Morris International R&D, Philip Morris Products S.A., 2000 Neuchatel, Switzerland
| | - Nikolai V Ivanov
- Philip Morris International R&D, Philip Morris Products S.A., 2000 Neuchatel, Switzerland
| | - Maria Selmer
- Department of Cell and Molecular Biology, Uppsala University, BMC, Box 596, 751 24 Uppsala, Sweden.
| | | | - Artem Isaev
- Skolkovo Institute of Science and Technology, Moscow 143028, Russia.
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5
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Dot EW, Thomason LC, Chappie JS. Everything OLD is new again: How structural, functional, and bioinformatic advances have redefined a neglected nuclease family. Mol Microbiol 2023; 120:122-140. [PMID: 37254295 DOI: 10.1111/mmi.15074] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 04/28/2023] [Accepted: 04/30/2023] [Indexed: 06/01/2023]
Abstract
Overcoming lysogenization defect (OLD) proteins are a conserved family of ATP-powered nucleases that function in anti-phage defense. Recent bioinformatic, genetic, and crystallographic studies have yielded new insights into the structure, function, and evolution of these enzymes. Here we review these developments and propose a new classification scheme to categorize OLD homologs that relies on gene neighborhoods, biochemical properties, domain organization, and catalytic machinery. This taxonomy reveals important similarities and differences between family members and provides a blueprint to contextualize future in vivo and in vitro findings. We also detail how OLD nucleases are related to PARIS and Septu anti-phage defense systems and discuss important mechanistic questions that remain unanswered.
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Affiliation(s)
- Elena Wanvig Dot
- Department of Molecular Medicine, Cornell University, Ithaca, New York, USA
| | - Lynn C Thomason
- Molecular Control and Genetics Section, RNA Biology Laboratory, National Cancer Institute at Frederick, National Institutes of Health, Frederick, Maryland, USA
| | - Joshua S Chappie
- Department of Molecular Medicine, Cornell University, Ithaca, New York, USA
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Lian ZJ, Phan MD, Hancock SJ, Nhu NTK, Paterson DL, Schembri MA. Genetic basis of I-complex plasmid stability and conjugation. PLoS Genet 2023; 19:e1010773. [PMID: 37347771 DOI: 10.1371/journal.pgen.1010773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 05/05/2023] [Indexed: 06/24/2023] Open
Abstract
Plasmids are major drivers of increasing antibiotic resistance, necessitating an urgent need to understand their biology. Here we describe a detailed dissection of the molecular components controlling the genetics of I-complex plasmids, a group of antibiotic resistance plasmids found frequently in pathogenic Escherichia coli and other Enterobacteriaceae that cause significant human disease. We show these plasmids cluster into four distinct subgroups, with the prototype IncI1 plasmid R64 subgroup displaying low nucleotide sequence conservation to other I-complex plasmids. Using pMS7163B, an I-complex plasmid distantly related to R64, we performed a high-resolution transposon-based genetic screen and defined genes involved in replication, stability, and conjugative transfer. We identified the replicon and a partitioning system as essential for replication/stability. Genes required for conjugation included the type IV secretion system, relaxosome, and several uncharacterised genes located in the pMS7163B leading transfer region that exhibited an upstream strand-specific transposon insertion bias. The overexpression of these genes severely impacted host cell growth or reduced fitness during mixed competitive growth, demonstrating that their expression must be controlled to avoid deleterious impacts. These genes were present in >80% of all I-complex plasmids and broadly conserved across multiple plasmid incompatibility groups, implicating an important role in plasmid dissemination.
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Affiliation(s)
- Zheng Jie Lian
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Minh-Duy Phan
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Steven J Hancock
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Nguyen Thi Khanh Nhu
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - David L Paterson
- The University of Queensland Centre for Clinical Research, Brisbane, Australia
| | - Mark A Schembri
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
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7
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Gulati P, Singh A, Goel M, Saha S. The extremophile Picrophilus torridus carries a DNA adenine methylase M.PtoI that is part of a Type I restriction-modification system. Front Microbiol 2023; 14:1126750. [PMID: 37007530 PMCID: PMC10050889 DOI: 10.3389/fmicb.2023.1126750] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 02/27/2023] [Indexed: 03/17/2023] Open
Abstract
DNA methylation events mediated by orphan methyltransferases modulate various cellular processes like replication, repair and transcription. Bacteria and archaea also harbor DNA methyltransferases that are part of restriction-modification systems, which serve to protect the host genome from being cleaved by the cognate restriction enzyme. While DNA methylation has been exhaustively investigated in bacteria it remains poorly understood in archaea. Picrophilus torridus is a euryarchaeon that can thrive under conditions of extremely low pH (0.7), and thus far no reports have been published regarding DNA methylation in this extremophile. This study reports the first experimentation examining DNA methylation in P. torridus. We find the genome to carry methylated adenine (m6A) but not methylated cytosine (m5C) residues. The m6A modification is absent at GATC sites, indicating the absence of an active Dam methylase even though the dam gene has been annotated in the genome sequence. Two other methylases have also been annotated in the P. torridus genome sequence. One of these is a part of a Type I restriction-modification system. Considering that all Type I modification methylases characterized to date target adenine residues, the modification methylase of this Type I system has been examined. The genes encoding the S subunit (that is responsible for DNA recognition) and M subunit (that is responsible for DNA methylation) have been cloned and the recombinant protein purified from E.coli, and regions involved in M-S interactions have been identified. The M.PtoI enzyme harbors all the motifs that typify Type I modification methylases, and displays robust adenine methylation in in vitro assays under a variety of conditions. Interestingly, magnesium is essential for enzyme activity. The enzyme displays substrate inhibition at higher concentrations of AdoMet. Mutational analyses reveal that Motif I plays a role in AdoMet binding, and Motif IV is critical for methylation activity. The data presented here lays the foundation for further research in the area of DNA methylation and restriction-modification research in this most unusual microorganism.
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Affiliation(s)
- Pallavi Gulati
- Department of Microbiology, University of Delhi South Campus, New Delhi, India
| | - Ashish Singh
- Department of Microbiology, University of Delhi South Campus, New Delhi, India
| | - Manisha Goel
- Department of Biophysics, University of Delhi South Campus, New Delhi, India
| | - Swati Saha
- Department of Microbiology, University of Delhi South Campus, New Delhi, India
- *Correspondence: Swati Saha, ;
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Gao Q, Lu S, Wang Y, He L, Wang M, Jia R, Chen S, Zhu D, Liu M, Zhao X, Yang Q, Wu Y, Zhang S, Huang J, Mao S, Ou X, Sun D, Tian B, Cheng A. Bacterial DNA methyltransferase: A key to the epigenetic world with lessons learned from proteobacteria. Front Microbiol 2023; 14:1129437. [PMID: 37032876 PMCID: PMC10073500 DOI: 10.3389/fmicb.2023.1129437] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Epigenetics modulates expression levels of various important genes in both prokaryotes and eukaryotes. These epigenetic traits are heritable without any change in genetic DNA sequences. DNA methylation is a universal mechanism of epigenetic regulation in all kingdoms of life. In bacteria, DNA methylation is the main form of epigenetic regulation and plays important roles in affecting clinically relevant phenotypes, such as virulence, host colonization, sporulation, biofilm formation et al. In this review, we survey bacterial epigenomic studies and focus on the recent developments in the structure, function, and mechanism of several highly conserved bacterial DNA methylases. These methyltransferases are relatively common in bacteria and participate in the regulation of gene expression and chromosomal DNA replication and repair control. Recent advances in sequencing techniques capable of detecting methylation signals have enabled the characterization of genome-wide epigenetic regulation. With their involvement in critical cellular processes, these highly conserved DNA methyltransferases may emerge as promising targets for developing novel epigenetic inhibitors for biomedical applications.
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Affiliation(s)
- Qun Gao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
| | - Shuwei Lu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yuwei Wang
- Key Laboratory of Livestock and Poultry Provenance Disease Research in Mianyang, Sichuan, China
| | - Longgui He
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mingshu Wang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Renyong Jia
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shun Chen
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Dekang Zhu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mafeng Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xinxin Zhao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qiao Yang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Ying Wu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shaqiu Zhang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Juan Huang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Sai Mao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xumin Ou
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Di Sun
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Bin Tian
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Anchun Cheng
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
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Semashko TA, Arzamasov AA, Evsyutina DV, Garanina IA, Matyushkina DS, Ladygina VG, Pobeguts OV, Fisunov GY, Govorun VM. Role of DNA modifications in Mycoplasma gallisepticum. PLoS One 2022; 17:e0277819. [PMID: 36413541 PMCID: PMC9681074 DOI: 10.1371/journal.pone.0277819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/03/2022] [Indexed: 11/23/2022] Open
Abstract
The epigenetics of bacteria, and bacteria with a reduced genome in particular, is of great interest, but is still poorly understood. Mycoplasma gallisepticum, a representative of the class Mollicutes, is an excellent model of a minimal cell because of its reduced genome size, lack of a cell wall, and primitive cell organization. In this study we investigated DNA modifications of the model object Mycoplasma gallisepticum and their roles. We identified DNA modifications and methylation motifs in M. gallisepticum S6 at the genome level using single molecule real time (SMRT) sequencing. Only the ANCNNNNCCT methylation motif was found in the M. gallisepticum S6 genome. The studied bacteria have one functional system for DNA modifications, the Type I restriction-modification (RM) system, MgaS6I. We characterized its activity, affinity, protection and epigenetic functions. We demonstrated the protective effects of this RM system. A common epigenetic signal for bacteria is the m6A modification we found, which can cause changes in DNA-protein interactions and affect the cell phenotype. Native methylation sites are underrepresented in promoter regions and located only near the -35 box of the promoter, which does not have a significant effect on gene expression in mycoplasmas. To study the epigenetics effect of m6A for genome-reduced bacteria, we constructed a series of M. gallisepticum strains expressing EGFP under promoters with the methylation motifs in their different elements. We demonstrated that m6A modifications of the promoter located only in the -10-box affected gene expression and downregulated the expression of the corresponding gene.
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Affiliation(s)
- Tatiana A. Semashko
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
- Research Institute for Systems Biology and Medicine, Moscow, Russian Federation
- * E-mail:
| | - Alexander A. Arzamasov
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
| | - Daria V. Evsyutina
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
- Research Institute for Systems Biology and Medicine, Moscow, Russian Federation
| | - Irina A. Garanina
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
| | - Daria S. Matyushkina
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
- Research Institute for Systems Biology and Medicine, Moscow, Russian Federation
| | - Valentina G. Ladygina
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
| | - Olga V. Pobeguts
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
| | - Gleb Y. Fisunov
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russian Federation
- Research Institute for Systems Biology and Medicine, Moscow, Russian Federation
| | - Vadim M. Govorun
- Research Institute for Systems Biology and Medicine, Moscow, Russian Federation
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10
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Zhu J, Gao Y, Wang Y, Zhan Q, Feng H, Luo X, Li P, Liu S, Hou H, Gao P. Molecular insights into DNA recognition and methylation by non-canonical type I restriction-modification systems. Nat Commun 2022; 13:6391. [PMID: 36302770 DOI: 10.1038/s41467-022-34085-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 10/11/2022] [Indexed: 12/25/2022] Open
Abstract
Type I restriction-modification systems help establish the prokaryotic DNA methylation landscape and provide protection against invasive DNA. In addition to classical m6A modifications, non-canonical type I enzymes catalyze both m6A and m4C using alternative DNA-modification subunits M1 and M2. Here, we report the crystal structures of the non-canonical PacII_M1M2S methyltransferase bound to target DNA and reaction product S-adenosylhomocysteine in a closed clamp-like conformation. Target DNA binds tightly within the central tunnel of the M1M2S complex and forms extensive contacts with all three protein subunits. Unexpectedly, while the target cytosine properly inserts into M2's pocket, the target adenine (either unmethylated or methylated) is anchored outside M1's pocket. A unique asymmetric catalysis is established where PacII_M1M2S has precisely coordinated the relative conformations of different subunits and evolved specific amino acids within M2/M1. This work provides insights into mechanisms of m6A/m4C catalysis and guidance for designing tools based on type I restriction-modification enzymes.
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11
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Seo PW, Hofmann A, Kim JH, Hwangbo SA, Kim JH, Kim JW, Huynh TYL, Choy HE, Kim SJ, Lee J, Lee JO, Jin KS, Park SY, Kim JS. Structural features of a minimal intact methyltransferase of a type I restriction-modification system. Int J Biol Macromol 2022; 208:381-389. [PMID: 35337914 DOI: 10.1016/j.ijbiomac.2022.03.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 11/05/2022]
Abstract
Type I restriction-modification enzymes are oligomeric proteins composed of methylation (M), DNA sequence-recognition (S), and restriction (R) subunits. The different bipartite DNA sequences of 2-4 consecutive bases are recognized by two discerned target recognition domains (TRDs) located at the two-helix bundle of the two conserved regions (CRs). Two M-subunits and a single S-subunit form an oligomeric protein that functions as a methyltransferase (M2S1 MTase). Here, we present the crystal structure of the intact MTase from Vibrio vulnificus YJ016 in complex with the DNA-mimicking Ocr protein and the S-adenosyl-L-homocysteine (SAH). This MTase includes the M-domain with a helix tail (M-tail helix) and the S1/2-domain of a TRD and a CR α-helix. The Ocr binds to the cleft of the TRD surface and SAH is located in the pocket within the M-domain. The solution- and negative-staining electron microscopy-based reconstructed (M1S1/2)2 structure reveals a symmetric (S1/2)2 assembly using two CR-helices and two M-tail helices as a pivot, which is plausible for recognizing two DNA regions of same sequence. The conformational flexibility of the minimal M1S1/2 MTase dimer indicates a particular state resembling the structure of M2S1 MTases.
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Affiliation(s)
- Pil-Won Seo
- Department of Chemistry, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Andreas Hofmann
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia; Max Rubner-Institut, Federal Research Institute of Nutrition and Food, 95326 Kulmbach, Germany
| | - Jun-Ha Kim
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea; Department of Chemical Engineering, Kumoh National Institute of Technology, 61, Daehak-ro, Gumi, Gyeongbuk 39177, Republic of Korea
| | - Seung-A Hwangbo
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea; Department of Life Sciences and Institute of Membrane Proteins, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Jun-Hong Kim
- Department of Chemistry, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Ji-Won Kim
- Department of Chemistry, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Thi Yen Ly Huynh
- Department of Chemistry, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Hyon E Choy
- Department of Microbiology, Basic Medical Research Building, Chonnam National University Medical College, Hwasun, Jeonnam 58128, Republic of Korea
| | - Soo-Jung Kim
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jimin Lee
- Department of Life Sciences and Institute of Membrane Proteins, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Jie-Oh Lee
- Department of Life Sciences and Institute of Membrane Proteins, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea.
| | - Suk-Youl Park
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea.
| | - Jeong-Sun Kim
- Department of Chemistry, Chonnam National University, Gwangju 61186, Republic of Korea.
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12
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Tuan VP, Yahara K, Dung HDQ, Binh TT, Huu Tung P, Tri TD, Thuan NPM, Khien VV, Trang TTH, Phuc BH, Tshibangu-Kabamba E, Matsumoto T, Akada J, Suzuki R, Okimoto T, Kodama M, Murakami K, Yano H, Fukuyo M, Takahashi N, Kato M, Nishiumi S, Azuma T, Ogura Y, Hayashi T, Toyoda A, Kobayashi I, Yamaoka Y. Genome-wide association study of gastric cancer- and duodenal ulcer-derived Helicobacter pylori strains reveals discriminatory genetic variations and novel oncoprotein candidates. Microb Genom 2021; 7. [PMID: 34846284 PMCID: PMC8743543 DOI: 10.1099/mgen.0.000680] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genome-wide association studies (GWASs) can reveal genetic variations associated with a phenotype in the absence of any hypothesis of candidate genes. The problem of false-positive sites linked with the responsible site might be bypassed in bacteria with a high homologous recombination rate, such as Helicobacter pylori, which causes gastric cancer. We conducted a small-sample GWAS (125 gastric cancer cases and 115 controls) followed by prediction of gastric cancer and control (duodenal ulcer) H. pylori strains. We identified 11 single nucleotide polymorphisms (eight amino acid changes) and three DNA motifs that, combined, allowed effective disease discrimination. They were often informative of the underlying molecular mechanisms, such as electric charge alteration at the ligand-binding pocket, alteration in subunit interaction, and mode-switching of DNA methylation. We also identified three novel virulence factors/oncoprotein candidates. These results provide both defined targets for further informatic and experimental analyses to gain insights into gastric cancer pathogenesis and a basis for identifying a set of biomarkers for distinguishing these H. pylori-related diseases.
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Affiliation(s)
- Vo Phuoc Tuan
- Department of Endoscopy, Cho Ray Hospital, Ho Chi Minh, Vietnam
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Koji Yahara
- Antimicrobial Resistance ResearchCenter, National Institute of Infectious Diseases, Tokyo, Japan
- *Correspondence: Koji Yahara,
| | | | - Tran Thanh Binh
- Department of Endoscopy, Cho Ray Hospital, Ho Chi Minh, Vietnam
| | - Pham Huu Tung
- Department of Endoscopy, Cho Ray Hospital, Ho Chi Minh, Vietnam
| | - Tran Dinh Tri
- Department of Endoscopy, Cho Ray Hospital, Ho Chi Minh, Vietnam
| | | | - Vu Van Khien
- Department of GI Endoscopy, 108 Central Hospital, Hanoi, Vietnam
| | | | - Bui Hoang Phuc
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
- Department of Microbiology, Cho Ray Hospital, Ho Chi Minh, Vietnam
| | | | - Takashi Matsumoto
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Junko Akada
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Rumiko Suzuki
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Tadayoshi Okimoto
- Department of Gastroenterology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Masaaki Kodama
- Department of Gastroenterology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Kazunari Murakami
- Department of Gastroenterology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Hirokazu Yano
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Masaki Fukuyo
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Molecular Oncology, Chiba University, Chiba, Japan
| | - Noriko Takahashi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Infectious Diseases, Kyorin University School of Medicine, Mitaka City, Tokyo, Japan
| | - Mototsugu Kato
- Division of Endoscopy, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
- Department of Gastroenterology, National Hospital Organization Hakodate Hospital, Hakodate, Hokkaido, Japan
| | - Shin Nishiumi
- Department of Gastroenterology, Graduate School of Medicine, Kobe University, Chuou-ku, Kobe, Hyogo, Japan
- Department of Omics Medicine, Hyogo College of Medicine, Hyogo, Japan
| | - Takashi Azuma
- Department of Gastroenterology, Graduate School of Medicine, Kobe University, Chuou-ku, Kobe, Hyogo, Japan
| | - Yoshitoshi Ogura
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
- Division of Microbiology, Department of Infectious Medicine, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Atsushi Toyoda
- Advanced GenomicsCenter, National Institute of Genetics, Shizuoka, Japan
| | - Ichizo Kobayashi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Infectious Diseases, Kyorin University School of Medicine, Mitaka City, Tokyo, Japan
- Research Center for Micro-Nano Technology, Hosei University, Tokyo, Japan
- *Correspondence: Ichizo Kobayashi, ;
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
- Department of Medicine, gastroenterology section, Baylor College of Medicine, Houston TX, USA
- *Correspondence: Yoshio Yamaoka,
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13
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Abstract
Like many organisms, bacteria and archaea have both innate and adaptive immune systems to defend against infection by viruses and other parasites. Innate immunity most commonly relies on the endonuclease-mediated cleavage of any incoming DNA that lacks a specific epigenetic modification, through a system known as restriction-modification. CRISPR-Cas-mediated adaptive immunity relies on the insertion of short DNA sequences from parasite genomes into CRISPR arrays on the host genome to provide sequence-specific protection. The discovery of each of these systems has revolutionised our ability to carry out genetic manipulations, and, as a consequence, the enzymes involved have been characterised in exquisite detail. In comparison, much less is known about the importance of these two arms of the defence for the ecology and evolution of prokaryotes and their parasites. Here, we review our current ecological and evolutionary understanding of these systems in isolation, and discuss the need to study how innate and adaptive immune responses are integrated when they coexist in the same cell.
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Affiliation(s)
- Tatiana Dimitriu
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK.
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK.
| | - Edze R Westra
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK.
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14
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Shen BW, Quispe JD, Luyten Y, McGough BE, Morgan RD, Stoddard BL. Coordination of phage genome degradation versus host genome protection by a bifunctional restriction-modification enzyme visualized by CryoEM. Structure 2021; 29:521-530.e5. [PMID: 33826880 PMCID: PMC8178248 DOI: 10.1016/j.str.2021.03.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/26/2021] [Accepted: 03/12/2021] [Indexed: 01/21/2023]
Abstract
Restriction enzymes that combine methylation and cleavage into a single assemblage and modify one DNA strand are capable of efficient adaptation toward novel targets. However, they must reliably cleave invasive DNA and methylate newly replicated unmodified host sites. One possible solution is to enforce a competition between slow methylation at a single unmodified host target, versus faster cleavage that requires multiple unmodified target sites in foreign DNA to be brought together in a reaction synapse. To examine this model, we have determined the catalytic behavior of a bifunctional type IIL restriction-modification enzyme and determined its structure, via cryoelectron microscopy, at several different stages of assembly and coordination with bound DNA targets. The structures demonstrate a mechanism in which an initial dimer is formed between two DNA-bound enzyme molecules, positioning the endonuclease domain from each enzyme against the other's DNA and requiring further additional DNA-bound enzyme molecules to enable cleavage.
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Affiliation(s)
- Betty W Shen
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, WA 98109, USA
| | - Joel D Quispe
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Yvette Luyten
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Benjamin E McGough
- Scientific Computing, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, WA 98109, USA
| | | | - Barry L Stoddard
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, WA 98109, USA.
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15
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Isaev A, Drobiazko A, Sierro N, Gordeeva J, Yosef I, Qimron U, Ivanov NV, Severinov K. Phage T7 DNA mimic protein Ocr is a potent inhibitor of BREX defence. Nucleic Acids Res 2020; 48:5397-5406. [PMID: 32338761 PMCID: PMC7261183 DOI: 10.1093/nar/gkaa290] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/08/2020] [Accepted: 04/16/2020] [Indexed: 11/12/2022] Open
Abstract
BREX (for BacteRiophage EXclusion) is a superfamily of common bacterial and archaeal defence systems active against diverse bacteriophages. While the mechanism of BREX defence is currently unknown, self versus non-self differentiation requires methylation of specific asymmetric sites in host DNA by BrxX (PglX) methyltransferase. Here, we report that T7 bacteriophage Ocr, a DNA mimic protein that protects the phage from the defensive action of type I restriction-modification systems, is also active against BREX. In contrast to the wild-type phage, which is resistant to BREX defence, T7 lacking Ocr is strongly inhibited by BREX, and its ability to overcome the defence could be complemented by Ocr provided in trans. We further show that Ocr physically associates with BrxX methyltransferase. Although BREX+ cells overproducing Ocr have partially methylated BREX sites, their viability is unaffected. The result suggests that, similar to its action against type I R-M systems, Ocr associates with as yet unidentified BREX system complexes containing BrxX and neutralizes their ability to both methylate and exclude incoming phage DNA.
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Affiliation(s)
- Artem Isaev
- Skolkovo Institute of Science and Technology, Moscow 143028, Russia
| | - Alena Drobiazko
- Skolkovo Institute of Science and Technology, Moscow 143028, Russia
| | - Nicolas Sierro
- Philip Morris International R&D, Philip Morris Products S.A., Neuchatel 2000, Switzerland
| | - Julia Gordeeva
- Skolkovo Institute of Science and Technology, Moscow 143028, Russia
| | - Ido Yosef
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Udi Qimron
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nikolai V Ivanov
- Philip Morris International R&D, Philip Morris Products S.A., Neuchatel 2000, Switzerland
| | - Konstantin Severinov
- Skolkovo Institute of Science and Technology, Moscow 143028, Russia
- Waksman Institute of Microbiology, Piscataway, NJ 08854, USA
- Institute of Gene Biology, Russian Academy of Sciences, Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov str., 119334 Moscow, Russia
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16
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Gao Y, Cao D, Zhu J, Feng H, Luo X, Liu S, Yan XX, Zhang X, Gao P. Structural insights into assembly, operation and inhibition of a type I restriction-modification system. Nat Microbiol 2020; 5:1107-1118. [PMID: 32483229 DOI: 10.1038/s41564-020-0731-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 04/29/2020] [Indexed: 11/09/2022]
Abstract
Type I restriction-modification (R-M) systems are widespread in prokaryotic genomes and provide robust protection against foreign DNA. They are multisubunit enzymes with methyltransferase, endonuclease and translocase activities. Despite extensive studies over the past five decades, little is known about the molecular mechanisms of these sophisticated machines. Here, we report the cryo-electron microscopy structures of the representative EcoR124I R-M system in different assemblies (R2M2S1, R1M2S1 and M2S1) bound to target DNA and the phage and mobile genetic element-encoded anti-restriction proteins Ocr and ArdA. EcoR124I can precisely regulate different enzymatic activities by adopting distinct conformations. The marked conformational transitions of EcoR124I are dependent on the intrinsic flexibility at both the individual-subunit and assembled-complex levels. Moreover, Ocr and ArdA use a DNA-mimicry strategy to inhibit multiple activities, but do not block the conformational transitions of the complexes. These structural findings, complemented by mutational studies of key intermolecular contacts, provide insights into assembly, operation and inhibition mechanisms of type I R-M systems.
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Affiliation(s)
- Yina Gao
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Duanfang Cao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jingpeng Zhu
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Han Feng
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xiu Luo
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Songqing Liu
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xiao-Xue Yan
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
| | - Pu Gao
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
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17
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Ye F, Kotta-Loizou I, Jovanovic M, Liu X, Dryden DT, Buck M, Zhang X. Structural basis of transcription inhibition by the DNA mimic protein Ocr of bacteriophage T7. eLife 2020; 9:52125. [PMID: 32039758 PMCID: PMC7064336 DOI: 10.7554/elife.52125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 02/08/2020] [Indexed: 01/25/2023] Open
Abstract
Bacteriophage T7 infects Escherichia coli and evades the host restriction/modification system. The Ocr protein of T7 was shown to exist as a dimer mimicking DNA and to bind to host restriction enzymes, thus preventing the degradation of the viral genome by the host. Here we report that Ocr can also inhibit host transcription by directly binding to bacterial RNA polymerase (RNAP) and competing with the recruitment of RNAP by sigma factors. Using cryo electron microscopy, we determined the structures of Ocr bound to RNAP. The structures show that an Ocr dimer binds to RNAP in the cleft, where key regions of sigma bind and where DNA resides during transcription synthesis, thus providing a structural basis for the transcription inhibition. Our results reveal the versatility of Ocr in interfering with host systems and suggest possible strategies that could be exploited in adopting DNA mimicry as a basis for forming novel antibiotics. Bacteria and viruses have long been fighting amongst themselves. Bacteriophages are a type of virus that invade bacteria; their name literally means ‘bacteria eater’. The bacteriophage T7, for example, infects the common bacteria known as Escherichia coli. Once inside, the virus hijacks the bacterium’s cellular machinery, using it to replicate its own genetic material and make more copies of the virus so it can spread. At the same time, the bacteria have found ways to try and defend themselves, which in turn has led some bacteriophages to develop countermeasures to overcome those defences. Many bacteria, for example, have restriction enzymes which recognise certain sections of the bacteriophage DNA and cut it into fragments. However, the T7 bacteriophage has one well-known protein called Ocr which inhibits restriction enzymes. Ocr does this by mimicking DNA, which led Ye et al. to wonder if it could also interrupt other vital processes in a bacterial cell that involve DNA. Transcription is the first step in a coordinated process that turns the genetic information stored in a cell’s DNA into useful proteins. An enzyme called RNA polymerase decodes the DNA sequence into a go-between molecule called messenger RNA, and it was here that Ye et al. thought Ocr might jump in to interfere. To begin, Ye et al. examined the structure of Ocr when it binds to RNA polymerase using an imaging technique called cryo-electron microscopy. Ocr has been well-studied before, its structure previously described, but not when attached to RNA polymerase. The analysis showed that Ocr gets in the way of specific molecules, called sigma factors, that show RNA polymerase where to start transcription. Ocr binds to RNA polymerase in exactly the same pocket as part of sigma factors do, which is also the place where DNA must be to be decoded to make messenger RNA. Ye et al. then performed experiments to show Ocr interfering with binding to RNA polymerase did indeed disrupt transcription. This means Ocr is quite versatile as it interferes with the RNA polymerase of the bacterial host and its restriction enzymes. Ocr’s strategy of mimicking DNA to interrupt transcription could be adopted as an approach to develop new antibiotics to stop bacterial infections. DNA transcription is an essential cellular process – without it, no cell can replicate and survive – and RNA polymerase is already a validated target for drugs. Following Ocr’s lead could provide a new way to stop infections, if the right drug can be designed to fit.
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Affiliation(s)
- Fuzhou Ye
- Section of Structural Biology, Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Ioly Kotta-Loizou
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Milija Jovanovic
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Xiaojiao Liu
- Section of Structural Biology, Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom.,College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - David Tf Dryden
- Department Biosciences, Durham University, Durham, United Kingdom
| | - Martin Buck
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Xiaodong Zhang
- Section of Structural Biology, Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
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18
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Bower EKM, Cooper LP, Roberts GA, White JH, Luyten Y, Morgan RD, Dryden DTF. A model for the evolution of prokaryotic DNA restriction-modification systems based upon the structural malleability of Type I restriction-modification enzymes. Nucleic Acids Res 2019; 46:9067-9080. [PMID: 30165537 PMCID: PMC6158711 DOI: 10.1093/nar/gky760] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 08/21/2018] [Indexed: 12/28/2022] Open
Abstract
Restriction Modification (RM) systems prevent the invasion of foreign genetic material into bacterial cells by restriction and protect the host's genetic material by methylation. They are therefore important in maintaining the integrity of the host genome. RM systems are currently classified into four types (I to IV) on the basis of differences in composition, target recognition, cofactors and the manner in which they cleave DNA. Comparing the structures of the different types, similarities can be observed suggesting an evolutionary link between these different types. This work describes the ‘deconstruction’ of a large Type I RM enzyme into forms structurally similar to smaller Type II RM enzymes in an effort to elucidate the pathway taken by Nature to form these different RM enzymes. Based upon the ability to engineer new enzymes from the Type I ‘scaffold’, an evolutionary pathway and the evolutionary pressures required to move along the pathway from Type I RM systems to Type II RM systems are proposed. Experiments to test the evolutionary model are discussed.
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Affiliation(s)
- Edward K M Bower
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Laurie P Cooper
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Gareth A Roberts
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - John H White
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Yvette Luyten
- New England Biolabs, 240 County Road, Ipswich, MA 01938-2723, USA
| | - Richard D Morgan
- New England Biolabs, 240 County Road, Ipswich, MA 01938-2723, USA
| | - David T F Dryden
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
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19
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Su T, Liu F, Chang Y, Guo Q, Wang J, Wang Q, Qi Q. The phage T4 DNA ligase mediates bacterial chromosome DSBs repair as single component non-homologous end joining. Synth Syst Biotechnol 2019; 4:107-112. [PMID: 31193309 PMCID: PMC6525309 DOI: 10.1016/j.synbio.2019.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 10/29/2022] Open
Abstract
DNA double-strand breaks (DSBs) are one of the most lethal forms of DNA damage that is not efficiently repaired in prokaryotes. Certain microorganisms can handle chromosomal DSBs using the error-prone non-homologous end joining (NHEJ) system and ultimately cause genome mutagenesis. Here, we demonstrated that Enterobacteria phage T4 DNA ligase alone is capable of mediating in vivo chromosome DSBs repair in Escherichia coli. The ligation efficiency of DSBs with T4 DNA ligase is one order of magnitude higher than the NHEJ system from Mycobacterium tuberculosis. This process introduces chromosome DNA excision with different sizes, which can be manipulated by regulating the activity of host-exonuclease RecBCD. The DNA deletion length reduced either by inactivating recB or expressing the RecBCD inhibitor Gam protein from λ phage. Furthermore, we also found single nucleotide substitutions at the DNA junction, suggesting that T4 DNA ligase, as a single component non-homologous end joining system, has great potential in genome mutagenesis, genome reduction and genome editing.
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Affiliation(s)
- Tianyuan Su
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Fapeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Yizhao Chang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Qi Guo
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Junshu Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Qian Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.,National Glycoengineering Center, Shandong University, Qingdao, 266237, People's Republic of China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.,CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, People's Republic of China
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20
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Bonomi M, Hanot S, Greenberg CH, Sali A, Nilges M, Vendruscolo M, Pellarin R. Bayesian Weighing of Electron Cryo-Microscopy Data for Integrative Structural Modeling. Structure 2018; 27:175-188.e6. [PMID: 30393052 DOI: 10.1016/j.str.2018.09.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 08/07/2018] [Accepted: 09/19/2018] [Indexed: 10/28/2022]
Abstract
Cryo-electron microscopy (cryo-EM) has become a mainstream technique for determining the structures of complex biological systems. However, accurate integrative structural modeling has been hampered by the challenges in objectively weighing cryo-EM data against other sources of information due to the presence of random and systematic errors, as well as correlations, in the data. To address these challenges, we introduce a Bayesian scoring function that efficiently and accurately ranks alternative structural models of a macromolecular system based on their consistency with a cryo-EM density map as well as other experimental and prior information. The accuracy of this approach is benchmarked using complexes of known structure and illustrated in three applications: the structural determination of the GroEL/GroES, RNA polymerase II, and exosome complexes. The approach is implemented in the open-source Integrative Modeling Platform (http://integrativemodeling.org), thus enabling integrative structure determination by combining cryo-EM data with other sources of information.
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Affiliation(s)
| | - Samuel Hanot
- Institut Pasteur, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, CNRS UMR 3528, C3BI USR 3756 CNRS & IP, Paris, France
| | - Charles H Greenberg
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Sciences, and California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, CA 94158, USA
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Sciences, and California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, CA 94158, USA
| | - Michael Nilges
- Institut Pasteur, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, CNRS UMR 3528, C3BI USR 3756 CNRS & IP, Paris, France
| | | | - Riccardo Pellarin
- Institut Pasteur, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, CNRS UMR 3528, C3BI USR 3756 CNRS & IP, Paris, France.
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21
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Grinkevich P, Sinha D, Iermak I, Guzanova A, Weiserova M, Ludwig J, Mesters JR, Ettrich RH. Crystal structure of a novel domain of the motor subunit of the Type I restriction enzyme EcoR124 involved in complex assembly and DNA binding. J Biol Chem 2018; 293:15043-15054. [PMID: 30054276 DOI: 10.1074/jbc.ra118.003978] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/19/2018] [Indexed: 01/30/2023] Open
Abstract
Although EcoR124 is one of the better-studied Type I restriction-modification enzymes, it still presents many challenges to detailed analyses because of its structural and functional complexity and missing structural information. In all available structures of its motor subunit HsdR, responsible for DNA translocation and cleavage, a large part of the HsdR C terminus remains unresolved. The crystal structure of the C terminus of HsdR, obtained with a crystallization chaperone in the form of pHluorin fusion and refined to 2.45 Å, revealed that this part of the protein forms an independent domain with its own hydrophobic core and displays a unique α-helical fold. The full-length HsdR model, based on the WT structure and the C-terminal domain determined here, disclosed a proposed DNA-binding groove lined by positively charged residues. In vivo and in vitro assays with a C-terminal deletion mutant of HsdR supported the idea that this domain is involved in complex assembly and DNA binding. Conserved residues identified through sequence analysis of the C-terminal domain may play a key role in protein-protein and protein-DNA interactions. We conclude that the motor subunit of EcoR124 comprises five structural and functional domains, with the fifth, the C-terminal domain, revealing a unique fold characterized by four conserved motifs in the IC subfamily of Type I restriction-modification systems. In summary, the structural and biochemical results reported here support a model in which the C-terminal domain of the motor subunit HsdR of the endonuclease EcoR124 is involved in complex assembly and DNA binding.
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Affiliation(s)
- Pavel Grinkevich
- From the Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Zamek 136, 373 33 Nove Hrady, Czech Republic.,the Faculty of Sciences, University of South Bohemia in Ceske Budejovice, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Dhiraj Sinha
- From the Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Zamek 136, 373 33 Nove Hrady, Czech Republic
| | - Iuliia Iermak
- From the Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Zamek 136, 373 33 Nove Hrady, Czech Republic.,the Department of Structural Cell Biology, Molecular Mechanisms of DNA Repair, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Alena Guzanova
- the Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Praha 4, Czech Republic
| | - Marie Weiserova
- the Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Praha 4, Czech Republic
| | - Jost Ludwig
- From the Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Zamek 136, 373 33 Nove Hrady, Czech Republic
| | - Jeroen R Mesters
- the Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, Lübeck, Germany, and
| | - Rüdiger H Ettrich
- From the Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Zamek 136, 373 33 Nove Hrady, Czech Republic, .,the College of Biomedical Sciences, Larkin University, Miami, Florida 33169
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22
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Ouellette M, Gogarten JP, Lajoie J, Makkay AM, Papke RT. Characterizing the DNA Methyltransferases of Haloferax volcanii via Bioinformatics, Gene Deletion, and SMRT Sequencing. Genes (Basel) 2018; 9:genes9030129. [PMID: 29495512 PMCID: PMC5867850 DOI: 10.3390/genes9030129] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 02/16/2018] [Accepted: 02/19/2018] [Indexed: 12/31/2022] Open
Abstract
DNA methyltransferases (MTases), which catalyze the methylation of adenine and cytosine bases in DNA, can occur in bacteria and archaea alongside cognate restriction endonucleases (REases) in restriction-modification (RM) systems or independently as orphan MTases. Although DNA methylation and MTases have been well-characterized in bacteria, research into archaeal MTases has been limited. A previous study examined the genomic DNA methylation patterns (methylome) of the halophilic archaeon Haloferax volcanii, a model archaeal system which can be easily manipulated in laboratory settings, via single-molecule real-time (SMRT) sequencing and deletion of a putative MTase gene (HVO_A0006). In this follow-up study, we deleted other putative MTase genes in H. volcanii and sequenced the methylomes of the resulting deletion mutants via SMRT sequencing to characterize the genes responsible for DNA methylation. The results indicate that deletion of putative RM genes HVO_0794, HVO_A0006, and HVO_A0237 in a single strain abolished methylation of the sole cytosine motif in the genome (Cm4TAG). Amino acid alignments demonstrated that HVO_0794 shares homology with characterized cytosine CTAG MTases in other organisms, indicating that this MTase is responsible for Cm4TAG methylation in H. volcanii. The CTAG motif has high density at only one of the origins of replication, and there is no relative increase in CTAG motif frequency in the genome of H. volcanii, indicating that CTAG methylation might not have effectively taken over the role of regulating DNA replication and mismatch repair in the organism as previously predicted. Deletion of the putative Type I RM operon rmeRMS (HVO_2269-2271) resulted in abolished methylation of the adenine motif in the genome (GCAm6BN₆VTGC). Alignments of the MTase (HVO_2270) and site specificity subunit (HVO_2271) demonstrate homology with other characterized Type I MTases and site specificity subunits, indicating that the rmeRMS operon is responsible for adenine methylation in H. volcanii. Together with HVO_0794, these genes appear to be responsible for all detected methylation in H. volcanii, even though other putative MTases (HVO_C0040, HVO_A0079) share homology with characterized MTases in other organisms. We also report the construction of a multi-RM deletion mutant (ΔRM), with multiple RM genes deleted and with no methylation detected via SMRT sequencing, which we anticipate will be useful for future studies on DNA methylation in H. volcanii.
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Affiliation(s)
- Matthew Ouellette
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - J Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - Jessica Lajoie
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - Andrea M Makkay
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
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23
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24
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Liu YP, Tang Q, Zhang JZ, Tian LF, Gao P, Yan XX. Structural basis underlying complex assembly and conformational transition of the type I R-M system. Proc Natl Acad Sci U S A 2017; 114:11151-6. [PMID: 28973912 DOI: 10.1073/pnas.1711754114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Type I restriction-modification (R-M) systems are multisubunit enzymes with separate DNA-recognition (S), methylation (M), and restriction (R) subunits. Despite extensive studies spanning five decades, the detailed molecular mechanisms underlying subunit assembly and conformational transition are still unclear due to the lack of high-resolution structural information. Here, we report the atomic structure of a type I MTase complex (2M+1S) bound to DNA and cofactor S-adenosyl methionine in the "open" form. The intermolecular interactions between M and S subunits are mediated by a four-helix bundle motif, which also determines the specificity of the interaction. Structural comparison between open and previously reported low-resolution "closed" structures identifies the huge conformational changes within the MTase complex. Furthermore, biochemical results show that R subunits prefer to load onto the closed form MTase. Based on our results, we proposed an updated model for the complex assembly. The work reported here provides guidelines for future applications in molecular biology.
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25
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Cooper LP, Roberts GA, White JH, Luyten YA, Bower EKM, Morgan RD, Roberts RJ, Lindsay JA, Dryden DTF. DNA target recognition domains in the Type I restriction and modification systems of Staphylococcus aureus. Nucleic Acids Res 2017; 45:3395-3406. [PMID: 28180279 PMCID: PMC5399793 DOI: 10.1093/nar/gkx067] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/03/2017] [Indexed: 12/18/2022] Open
Abstract
Staphylococcus aureus displays a clonal population structure in which horizontal gene transfer between different lineages is extremely rare. This is due, in part, to the presence of a Type I DNA restriction–modification (RM) system given the generic name of Sau1, which maintains different patterns of methylation on specific target sequences on the genomes of different lineages. We have determined the target sequences recognized by the Sau1 Type I RM systems present in a wide range of the most prevalent S. aureus lineages and assigned the sequences recognized to particular target recognition domains within the RM enzymes. We used a range of biochemical assays on purified enzymes and single molecule real-time sequencing on genomic DNA to determine these target sequences and their patterns of methylation. Knowledge of the main target sequences for Sau1 will facilitate the synthesis of new vectors for transformation of the most prevalent lineages of this ‘untransformable’ bacterium.
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Affiliation(s)
- Laurie P Cooper
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK
| | - Gareth A Roberts
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK
| | - John H White
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK
| | - Yvette A Luyten
- New England Biolabs, 240 County Road, Ipswich, MA 01938-2723, USA
| | - Edward K M Bower
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK
| | - Richard D Morgan
- New England Biolabs, 240 County Road, Ipswich, MA 01938-2723, USA
| | | | - Jodi A Lindsay
- Institute of Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - David T F Dryden
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK
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26
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Kato Y, Fukui K. Structure models of G72, the product of a susceptibility gene to schizophrenia. J Biochem 2017; 161:223-230. [PMID: 27815320 DOI: 10.1093/jb/mvw064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/07/2016] [Indexed: 11/15/2022] Open
Abstract
The G72 gene is one of the most susceptible genes to schizophrenia and is contained exclusively in the genomes of primates. The product of the G72 gene modulates the activity of D-amino acid oxidase (DAO) and is a small protein prone to aggregate, which hampers its structural studies. In addition, lack of a known structure of a homologue makes it difficult to use the homology modelling method for the prediction of the structure. Thus, we first developed a hybrid ab initio approach for small proteins prior to the prediction of the structure of G72. The approach uses three known ab initio algorithms. To evaluate the hybrid approach, we tested our prediction of the structure of the amino acid sequences whose structures were already solved and compared the predicted structures with the experimentally solved structures. Based on these comparisons, the average accuracy of our approach was calculated to be ∼5 Å. We then applied the approach to the sequence of G72 and successfully predicted the structures of the N- and C-terminal domains (ND and CD, respectively) of G72. The predicted structures of ND and CD were similar to membrane-bound proteins and adaptor proteins, respectively.
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Affiliation(s)
- Yusuke Kato
- Division of Enzyme Pathophysiology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
| | - Kiyoshi Fukui
- Division of Enzyme Pathophysiology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
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27
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Doberenz S, Eckweiler D, Reichert O, Jensen V, Bunk B, Spröer C, Kordes A, Frangipani E, Luong K, Korlach J, Heeb S, Overmann J, Kaever V, Häussler S. Identification of a Pseudomonas aeruginosa PAO1 DNA Methyltransferase, Its Targets, and Physiological Roles. mBio 2017; 8:e02312-16. [PMID: 28223461 DOI: 10.1128/mBio.02312-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
DNA methylation is widespread among prokaryotes, and most DNA methylation reactions are catalyzed by adenine DNA methyltransferases, which are part of restriction-modification (R-M) systems. R-M systems are known for their role in the defense against foreign DNA; however, DNA methyltransferases also play functional roles in gene regulation. In this study, we used single-molecule real-time (SMRT) sequencing to uncover the genome-wide DNA methylation pattern in the opportunistic pathogen Pseudomonas aeruginosa PAO1. We identified a conserved sequence motif targeted by an adenine methyltransferase of a type I R-M system and quantified the presence of N6-methyladenine using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Changes in the PAO1 methylation status were dependent on growth conditions and affected P. aeruginosa pathogenicity in a Galleria mellonella infection model. Furthermore, we found that methylated motifs in promoter regions led to shifts in sense and antisense gene expression, emphasizing the role of enzymatic DNA methylation as an epigenetic control of phenotypic traits in P. aeruginosa. Since the DNA methylation enzymes are not encoded in the core genome, our findings illustrate how the acquisition of accessory genes can shape the global P. aeruginosa transcriptome and thus may facilitate adaptation to new and challenging habitats. With the introduction of advanced technologies, epigenetic regulation by DNA methyltransferases in bacteria has become a subject of intense studies. Here we identified an adenosine DNA methyltransferase in the opportunistic pathogen Pseudomonas aeruginosa PAO1, which is responsible for DNA methylation of a conserved sequence motif. The methylation level of all target sequences throughout the PAO1 genome was approximated to be in the range of 65 to 85% and was dependent on growth conditions. Inactivation of the methyltransferase revealed an attenuated-virulence phenotype in the Galleria mellonella infection model. Furthermore, differential expression of more than 90 genes was detected, including the small regulatory RNA prrF1, which contributes to a global iron-sparing response via the repression of a set of gene targets. Our finding of a methylation-dependent repression of the antisense transcript of the prrF1 small regulatory RNA significantly expands our understanding of the regulatory mechanisms underlying active DNA methylation in bacteria.
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28
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Wilkinson M, Troman LA, Wan Nur Ismah WAK, Chaban Y, Avison MB, Dillingham MS, Wigley DB. Structural basis for the inhibition of RecBCD by Gam and its synergistic antibacterial effect with quinolones. eLife 2016; 5:e22963. [PMID: 28009252 PMCID: PMC5218532 DOI: 10.7554/elife.22963] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 12/22/2016] [Indexed: 12/11/2022] Open
Abstract
Our previous paper (Wilkinson et al, 2016) used high-resolution cryo-electron microscopy to solve the structure of the Escherichia coli RecBCD complex, which acts in both the repair of double-stranded DNA breaks and the degradation of bacteriophage DNA. To counteract the latter activity, bacteriophage λ encodes a small protein inhibitor called Gam that binds to RecBCD and inactivates the complex. Here, we show that Gam inhibits RecBCD by competing at the DNA-binding site. The interaction surface is extensive and involves molecular mimicry of the DNA substrate. We also show that expression of Gam in E. coli or Klebsiella pneumoniae increases sensitivity to fluoroquinolones; antibacterials that kill cells by inhibiting topoisomerases and inducing double-stranded DNA breaks. Furthermore, fluoroquinolone-resistance in K. pneumoniae clinical isolates is reversed by expression of Gam. Together, our data explain the synthetic lethality observed between topoisomerase-induced DNA breaks and the RecBCD gene products, suggesting a new co-antibacterial strategy.
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Affiliation(s)
- Martin Wilkinson
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Luca A Troman
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Wan AK Wan Nur Ismah
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Yuriy Chaban
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Matthew B Avison
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Mark S Dillingham
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Dale B Wigley
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
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29
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Morgan RD, Luyten YA, Johnson SA, Clough EM, Clark TA, Roberts RJ. Novel m4C modification in type I restriction-modification systems. Nucleic Acids Res 2016; 44:9413-9425. [PMID: 27580720 PMCID: PMC5100572 DOI: 10.1093/nar/gkw743] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/12/2016] [Indexed: 11/12/2022] Open
Abstract
We identify a new subgroup of Type I Restriction-Modification enzymes that modify cytosine in one DNA strand and adenine in the opposite strand for host protection. Recognition specificity has been determined for ten systems using SMRT sequencing and each recognizes a novel DNA sequence motif. Previously characterized Type I systems use two identical copies of a single methyltransferase (MTase) subunit, with one bound at each half site of the specificity (S) subunit to form the MTase. The new m4C-producing Type I systems we describe have two separate yet highly similar MTase subunits that form a heterodimeric M1M2S MTase. The MTase subunits from these systems group into two families, one of which has NPPF in the highly conserved catalytic motif IV and modifies adenine to m6A, and one having an NPPY catalytic motif IV and modifying cytosine to m4C. The high degree of similarity among their cytosine-recognizing components (MTase and S) suggest they have recently evolved, most likely from the far more common m6A Type I systems. Type I enzymes that modify cytosine exclusively were formed by replacing the adenine target recognition domain (TRD) with a cytosine-recognizing TRD. These are the first examples of m4C modification in Type I RM systems.
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Affiliation(s)
| | - Yvette A Luyten
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | | | - Emily M Clough
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Tyson A Clark
- Pacific Biosciences, 1380 Willow Road, Menlo Park, CA 94025, USA
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30
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Kanwar N, Roberts GA, Cooper LP, Stephanou AS, Dryden DTF. The evolutionary pathway from a biologically inactive polypeptide sequence to a folded, active structural mimic of DNA. Nucleic Acids Res 2016; 44:4289-303. [PMID: 27095198 PMCID: PMC4872106 DOI: 10.1093/nar/gkw234] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 03/24/2016] [Indexed: 11/13/2022] Open
Abstract
The protein Ocr (overcome classical restriction) from bacteriophage T7 acts as a mimic of DNA and inhibits all Type I restriction/modification (RM) enzymes. Ocr is a homodimer of 116 amino acids and adopts an elongated structure that resembles the shape of a bent 24 bp DNA molecule. Each monomer includes 34 acidic residues and only six basic residues. We have delineated the mimicry of Ocr by focusing on the electrostatic contribution of its negatively charged amino acids using directed evolution of a synthetic form of Ocr, termed pocr, in which all of the 34 acidic residues were substituted for a neutral amino acid. In vivo analyses confirmed that pocr did not display any antirestriction activity. Here, we have subjected the gene encoding pocr to several rounds of directed evolution in which codons for the corresponding acidic residues found in Ocr were specifically re-introduced. An in vivo selection assay was used to detect antirestriction activity after each round of mutation. Our results demonstrate the variation in importance of the acidic residues in regions of Ocr corresponding to different parts of the DNA target which it is mimicking and for the avoidance of deleterious effects on the growth of the host.
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Affiliation(s)
- Nisha Kanwar
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Gareth A Roberts
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Laurie P Cooper
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Augoustinos S Stephanou
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - David T F Dryden
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
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31
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Chen K, Stephanou AS, Roberts GA, White JH, Cooper LP, Houston PJ, Lindsay JA, Dryden DTF. The Type I Restriction Enzymes as Barriers to Horizontal Gene Transfer: Determination of the DNA Target Sequences Recognised by Livestock-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complexes 133/ST771 and 398. Adv Exp Med Biol 2016; 915:81-97. [PMID: 27193539 DOI: 10.1007/978-3-319-32189-9_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The Type I DNA restriction-modification (RM) systems of Staphylococcus aureus are known to act as a significant barrier to horizontal gene transfer between S. aureus strains belonging to different clonal complexes. The livestock-associated clonal complexes CC133/771 and CC398 contain Type I RM systems not found in human MRSA strains as yet but at some point transfer will occur. When this does take place, horizontal gene transfer of resistance will happen more easily between these strains. The reservoir of antibiotic resistance, virulence and host-adaptation genes present in livestock-associated MRSA will then potentially contribute to the development of newly evolving MRSA clones. The target sites recognised by the Type I RM systems of CC133/771 and CC398 were identified as CAG(N)5RTGA and ACC(N)5RTGA, respectively. Assuming that these enzymes recognise the methylation state of adenine, the underlined A and T bases indicate the unique positions of methylation. Target methylation points for enzymes from CC1 were also identified. The methylation points for CC1-1 are CCAY(N)5TTAA and those for CC1-2 are CCAY(N)6 TGT with the underline indicating the adenine methylation site thus clearing up the ambiguity noted previously (Roberts et al. 2013, Nucleic Acids Res 41:7472-7484) for the half sites containing two adenine bases.
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Affiliation(s)
- Kai Chen
- EaStCHEM School of Chemistry, University of Edinburgh the King's Buildings, Edinburgh, EH9 3JJ, UK.,Shenyang Research Institute of Chemical Industry, 8 Shenliao Dong Road, Shenyang, Liaoning, People's Republic of China
| | - Augoustinos S Stephanou
- EaStCHEM School of Chemistry, University of Edinburgh the King's Buildings, Edinburgh, EH9 3JJ, UK
| | - Gareth A Roberts
- EaStCHEM School of Chemistry, University of Edinburgh the King's Buildings, Edinburgh, EH9 3JJ, UK
| | - John H White
- EaStCHEM School of Chemistry, University of Edinburgh the King's Buildings, Edinburgh, EH9 3JJ, UK
| | - Laurie P Cooper
- EaStCHEM School of Chemistry, University of Edinburgh the King's Buildings, Edinburgh, EH9 3JJ, UK
| | - Patrick J Houston
- Institute of Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.,The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK
| | - Jodi A Lindsay
- Institute of Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.
| | - David T F Dryden
- EaStCHEM School of Chemistry, University of Edinburgh the King's Buildings, Edinburgh, EH9 3JJ, UK.
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32
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Ho CH, Wang HC, Ko TP, Chang YC, Wang AHJ. The T4 phage DNA mimic protein Arn inhibits the DNA binding activity of the bacterial histone-like protein H-NS. J Biol Chem 2014; 289:27046-27054. [PMID: 25118281 DOI: 10.1074/jbc.m114.590851] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The T4 phage protein Arn (Anti restriction nuclease) was identified as an inhibitor of the restriction enzyme McrBC. However, until now its molecular mechanism remained unclear. In the present study we used structural approaches to investigate biological properties of Arn. A structural analysis of Arn revealed that its shape and negative charge distribution are similar to dsDNA, suggesting that this protein could act as a DNA mimic. In a subsequent proteomic analysis, we found that the bacterial histone-like protein H-NS interacts with Arn, implying a new function. An electrophoretic mobility shift assay showed that Arn prevents H-NS from binding to the Escherichia coli hns and T4 p8.1 promoters. In vitro gene expression and electron microscopy analyses also indicated that Arn counteracts the gene-silencing effect of H-NS on a reporter gene. Because McrBC and H-NS both participate in the host defense system, our findings suggest that T4 Arn might knock down these mechanisms using its DNA mimicking properties.
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Affiliation(s)
- Chun-Han Ho
- Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan,; Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Hao-Ching Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan; Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan; Core Facilities for Protein Structural Analysis, and Academia Sinica, Taipei 115, Taiwan
| | - Yuan-Chih Chang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, and
| | - Andrew H-J Wang
- Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan,; Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan; Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan; Core Facilities for Protein Structural Analysis, and Academia Sinica, Taipei 115, Taiwan.
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Abstract
DNA mimic proteins have DNA-like negative surface charge distributions, and they function by occupying the DNA binding sites of DNA binding proteins to prevent these sites from being accessed by DNA. DNA mimic proteins control the activities of a variety of DNA binding proteins and are involved in a wide range of cellular mechanisms such as chromatin assembly, DNA repair, transcription regulation, and gene recombination. However, the sequences and structures of DNA mimic proteins are diverse, making them difficult to predict by bioinformatic search. To date, only a few DNA mimic proteins have been reported. These DNA mimics were not found by searching for functional motifs in their sequences but were revealed only by structural analysis of their charge distribution. This review highlights the biological roles and structures of 16 reported DNA mimic proteins. We also discuss approaches that might be used to discover new DNA mimic proteins.
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Affiliation(s)
- Hao-Ching Wang
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University , Taipei 110, Taiwan
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Huynh Thi Yen L, Park SY, Kim JS. Cloning, crystallization and preliminary X-ray diffraction analysis of an intact DNA methyltransferase of a type I restriction-modification enzyme from Vibrio vulnificus. Acta Crystallogr F Struct Biol Commun 2014; 70:489-92. [PMID: 24699746 PMCID: PMC3976070 DOI: 10.1107/s2053230x14004543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 02/27/2014] [Indexed: 11/10/2022] Open
Abstract
Independently of the restriction (HsdR) subunit, the specificity (HsdS) and methylation (HsdM) subunits interact with each other, and function as a methyltransferase in type I restriction-modification systems. A single gene that combines the HsdS and HsdM subunits in Vibrio vulnificus YJ016 was expressed and purified. A crystal suitable for X-ray diffraction was obtained from 25%(w/v) polyethylene glycol monomethylether 5000, 0.1 M HEPES pH 8.0, 0.2 M ammonium sulfate at 291 K by hanging-drop vapour diffusion. Diffraction data were collected to a resolution of 2.31 Å using synchrotron radiation. The crystal belonged to the primitive monoclinic space group P21, with unit-cell parameters a = 93.25, b = 133.04, c = 121.49 Å, β = 109.7°. With four molecules in the asymmetric unit, the crystal volume per unit protein weight was 2.61 Å(3) Da(-1), corresponding to a solvent content of 53%.
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Affiliation(s)
- Ly Huynh Thi Yen
- Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Suk-Youl Park
- Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Jeong-Sun Kim
- Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea
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35
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Loenen WAM, Dryden DTF, Raleigh EA, Wilson GG. Type I restriction enzymes and their relatives. Nucleic Acids Res 2014; 42:20-44. [PMID: 24068554 PMCID: PMC3874165 DOI: 10.1093/nar/gkt847] [Citation(s) in RCA: 171] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 08/26/2013] [Accepted: 08/29/2013] [Indexed: 12/24/2022] Open
Abstract
Type I restriction enzymes (REases) are large pentameric proteins with separate restriction (R), methylation (M) and DNA sequence-recognition (S) subunits. They were the first REases to be discovered and purified, but unlike the enormously useful Type II REases, they have yet to find a place in the enzymatic toolbox of molecular biologists. Type I enzymes have been difficult to characterize, but this is changing as genome analysis reveals their genes, and methylome analysis reveals their recognition sequences. Several Type I REases have been studied in detail and what has been learned about them invites greater attention. In this article, we discuss aspects of the biochemistry, biology and regulation of Type I REases, and of the mechanisms that bacteriophages and plasmids have evolved to evade them. Type I REases have a remarkable ability to change sequence specificity by domain shuffling and rearrangements. We summarize the classic experiments and observations that led to this discovery, and we discuss how this ability depends on the modular organizations of the enzymes and of their S subunits. Finally, we describe examples of Type II restriction-modification systems that have features in common with Type I enzymes, with emphasis on the varied Type IIG enzymes.
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Affiliation(s)
- Wil A. M. Loenen
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
| | - David T. F. Dryden
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
| | - Elisabeth A. Raleigh
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
| | - Geoffrey G. Wilson
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
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Loenen WAM, Dryden DTF, Raleigh EA, Wilson GG, Murray NE. Highlights of the DNA cutters: a short history of the restriction enzymes. Nucleic Acids Res 2014; 42:3-19. [PMID: 24141096 PMCID: PMC3874209 DOI: 10.1093/nar/gkt990] [Citation(s) in RCA: 195] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 09/24/2013] [Accepted: 10/02/2013] [Indexed: 11/16/2022] Open
Abstract
In the early 1950's, 'host-controlled variation in bacterial viruses' was reported as a non-hereditary phenomenon: one cycle of viral growth on certain bacterial hosts affected the ability of progeny virus to grow on other hosts by either restricting or enlarging their host range. Unlike mutation, this change was reversible, and one cycle of growth in the previous host returned the virus to its original form. These simple observations heralded the discovery of the endonuclease and methyltransferase activities of what are now termed Type I, II, III and IV DNA restriction-modification systems. The Type II restriction enzymes (e.g. EcoRI) gave rise to recombinant DNA technology that has transformed molecular biology and medicine. This review traces the discovery of restriction enzymes and their continuing impact on molecular biology and medicine.
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Affiliation(s)
- Wil A. M. Loenen
- Leiden University Medical Center, Leiden, the Netherlands, EaStChemSchool of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, UK and New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - David T. F. Dryden
- Leiden University Medical Center, Leiden, the Netherlands, EaStChemSchool of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, UK and New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Elisabeth A. Raleigh
- Leiden University Medical Center, Leiden, the Netherlands, EaStChemSchool of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, UK and New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Geoffrey G. Wilson
- Leiden University Medical Center, Leiden, the Netherlands, EaStChemSchool of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, UK and New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
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37
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Chen K, Reuter M, Sanghvi B, Roberts GA, Cooper LP, Tilling M, Blakely GW, Dryden DTF. ArdA proteins from different mobile genetic elements can bind to the EcoKI Type I DNA methyltransferase of E. coli K12. Biochim Biophys Acta 2013; 1844:505-11. [PMID: 24368349 PMCID: PMC3969726 DOI: 10.1016/j.bbapap.2013.12.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/11/2013] [Accepted: 12/13/2013] [Indexed: 12/11/2022]
Abstract
Anti-restriction and anti-modification (anti-RM) is the ability to prevent cleavage by DNA restriction–modification (RM) systems of foreign DNA entering a new bacterial host. The evolutionary consequence of anti-RM is the enhanced dissemination of mobile genetic elements. Homologues of ArdA anti-RM proteins are encoded by genes present in many mobile genetic elements such as conjugative plasmids and transposons within bacterial genomes. The ArdA proteins cause anti-RM by mimicking the DNA structure bound by Type I RM enzymes. We have investigated ArdA proteins from the genomes of Enterococcus faecalis V583, Staphylococcus aureus Mu50 and Bacteroides fragilis NCTC 9343, and compared them to the ArdA protein expressed by the conjugative transposon Tn916. We find that despite having very different structural stability and secondary structure content, they can all bind to the EcoKI methyltransferase, a core component of the EcoKI Type I RM system. This finding indicates that the less structured ArdA proteins become fully folded upon binding. The ability of ArdA from diverse mobile elements to inhibit Type I RM systems from other bacteria suggests that they are an advantage for transfer not only between closely-related bacteria but also between more distantly related bacterial species. Diverse ArdA proteins all target the EcoKI Type I DNA modification enzyme. ArdA proteins have variable secondary structure content. ArdA all bind equally well to EcoKI despite stability variations.
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Affiliation(s)
- Kai Chen
- EaStCHEM School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK
| | - Marcel Reuter
- EaStCHEM School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK
| | - Bansi Sanghvi
- EaStCHEM School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK
| | - Gareth A Roberts
- EaStCHEM School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK
| | - Laurie P Cooper
- EaStCHEM School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK
| | - Matthew Tilling
- EaStCHEM School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK
| | - Garry W Blakely
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JR, UK
| | - David T F Dryden
- EaStCHEM School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK
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38
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Roberts GA, Chen K, Bower EKM, Madrzak J, Woods A, Barker AM, Cooper LP, White JH, Blakely GW, Manfield I, Dryden DTF. Mutations of the domain forming the dimeric interface of the ArdA protein affect dimerization and antimodification activity but not antirestriction activity. FEBS J 2013; 280:4903-14. [PMID: 23910724 PMCID: PMC3906837 DOI: 10.1111/febs.12467] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 07/26/2013] [Accepted: 07/29/2013] [Indexed: 12/25/2022]
Abstract
ArdA antirestriction proteins are encoded by genes present in many conjugative plasmids and transposons within bacterial genomes. Antirestriction is the ability to prevent cleavage of foreign incoming DNA by restriction-modification (RM) systems. Antimodification, the ability to inhibit modification by the RM system, can also be observed with some antirestriction proteins. As these mobile genetic elements can transfer antibiotic resistance genes, the ArdA proteins assist their spread. The consequence of antirestriction is therefore the enhanced dissemination of mobile genetic elements. ArdA proteins cause antirestriction by mimicking the DNA structure bound by Type I RM enzymes. The crystal structure of ArdA showed it to be a dimeric protein with a highly elongated curved cylindrical shape [McMahon SA et al. (2009) Nucleic Acids Res37, 4887–4897]. Each monomer has three domains covered with negatively charged side chains and a very small interface with the other monomer. We investigated the role of the domain forming the dimer interface for ArdA activity via site-directed mutagenesis. The antirestriction activity of ArdA was maintained when up to seven mutations per monomer were made or the interface was disrupted such that the protein could only exist as a monomer. The antimodification activity of ArdA was lost upon mutation of this domain. The ability of the monomeric form of ArdA to function in antirestriction suggests, first, that it can bind independently to the restriction subunit or the modification subunits of the RM enzyme, and second, that the many ArdA homologues with long amino acid extensions, present in sequence databases, may be active in antirestriction.
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Roberts GA, Houston PJ, White JH, Chen K, Stephanou AS, Cooper LP, Dryden DTF, Lindsay JA. Impact of target site distribution for Type I restriction enzymes on the evolution of methicillin-resistant Staphylococcus aureus (MRSA) populations. Nucleic Acids Res 2013; 41:7472-84. [PMID: 23771140 PMCID: PMC3753647 DOI: 10.1093/nar/gkt535] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A limited number of Methicillin-resistant Staphylococcus aureus (MRSA) clones are responsible for MRSA infections worldwide, and those of different lineages carry unique Type I restriction-modification (RM) variants. We have identified the specific DNA sequence targets for the dominant MRSA lineages CC1, CC5, CC8 and ST239. We experimentally demonstrate that this RM system is sufficient to block horizontal gene transfer between clinically important MRSA, confirming the bioinformatic evidence that each lineage is evolving independently. Target sites are distributed randomly in S. aureus genomes, except in a set of large conjugative plasmids encoding resistance genes that show evidence of spreading between two successful MRSA lineages. This analysis of the identification and distribution of target sites explains evolutionary patterns in a pathogenic bacterium. We show that a lack of specific target sites enables plasmids to evade the Type I RM system thereby contributing to the evolution of increasingly resistant community and hospital MRSA.
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Affiliation(s)
- Gareth A Roberts
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK and Division of Clinical Sciences, St. George's, University of London, Cranmer Terrace, London, SW17 0RE, UK
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40
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Taylor JE, Swiderska A, Geoff Kneale G. A rapid purification procedure for the HsdM protein of EcoR124I and biophysical characterization of the purified protein. Protein Expr Purif 2013; 87:136-40. [DOI: 10.1016/j.pep.2012.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 11/07/2012] [Accepted: 11/08/2012] [Indexed: 10/27/2022]
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41
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Abstract
Bacteriophages T7, λ, P22, and P2/P4 (from Escherichia coli), as well as ϕ29 (from Bacillus subtilis), are among the best-studied bacterial viruses. This chapter summarizes published protein interaction data of intraviral protein interactions, as well as known phage-host protein interactions of these phages retrieved from the literature. We also review the published results of comprehensive protein interaction analyses of Pneumococcus phages Dp-1 and Cp-1, as well as coliphages λ and T7. For example, the ≈55 proteins encoded by the T7 genome are connected by ≈43 interactions with another ≈15 between the phage and its host. The chapter compiles published interactions for the well-studied phages λ (33 intra-phage/22 phage-host), P22 (38/9), P2/P4 (14/3), and ϕ29 (20/2). We discuss whether different interaction patterns reflect different phage lifestyles or whether they may be artifacts of sampling. Phages that infect the same host can interact with different host target proteins, as exemplified by E. coli phage λ and T7. Despite decades of intensive investigation, only a fraction of these phage interactomes are known. Technical limitations and a lack of depth in many studies explain the gaps in our knowledge. Strategies to complete current interactome maps are described. Although limited space precludes detailed overviews of phage molecular biology, this compilation will allow future studies to put interaction data into the context of phage biology.
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Affiliation(s)
- Roman Häuser
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Karlsruhe, Germany
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Park SY, Lee HJ, Song JM, Sun J, Hwang HJ, Nishi K, Kim JS. Structural characterization of a modification subunit of a putative type I restriction enzyme from Vibrio vulnificus YJ016. Acta Crystallogr D Biol Crystallogr 2012; 68:1570-7. [PMID: 23090406 DOI: 10.1107/s0907444912038826] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 09/10/2012] [Indexed: 11/10/2022]
Abstract
In multifunctional type I restriction enzymes, active methyltransferases (MTases) are constituted of methylation (HsdM) and specificity (HsdS) subunits. In this study, the crystal structure of a putative HsdM subunit from Vibrio vulnificus YJ016 (vvHsdM) was elucidated at a resolution of 1.80 Å. A cofactor-binding site for S-adenosyl-L-methionine (SAM, a methyl-group donor) is formed within the C-terminal domain of an α/β-fold, in which a number of residues are conserved, including the GxGG and (N/D)PP(F/Y) motifs, which are likely to interact with several functional moieties of the SAM methyl-group donor. Comparison with the N6 DNA MTase of Thermus aquaticus and other HsdM structures suggests that two aromatic rings (Phe199 and Phe312) in the motifs that are conserved among the HsdMs may sandwich both sides of the adenine ring of the recognition sequence so that a conserved Asn residue (Asn309) can interact with the N6 atom of the target adenine base (a methyl-group acceptor) and locate the target adenine base close to the transferred SAM methyl group.
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Affiliation(s)
- Suk-Youl Park
- Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea
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Roberts GA, Chen K, Cooper LP, White JH, Blakely GW, Dryden DTF. Removal of a frameshift between the hsdM and hsdS genes of the EcoKI Type IA DNA restriction and modification system produces a new type of system and links the different families of Type I systems. Nucleic Acids Res 2012; 40:10916-24. [PMID: 23002145 PMCID: PMC3510504 DOI: 10.1093/nar/gks876] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The EcoKI DNA methyltransferase is a trimeric protein comprised of two modification subunits (M) and one sequence specificity subunit (S). This enzyme forms the core of the EcoKI restriction/modification (RM) enzyme. The 3' end of the gene encoding the M subunit overlaps by 1 nt the start of the gene for the S subunit. Translation from the two different open reading frames is translationally coupled. Mutagenesis to remove the frameshift and fuse the two subunits together produces a functional RM enzyme in vivo with the same properties as the natural EcoKI system. The fusion protein can be purified and forms an active restriction enzyme upon addition of restriction subunits and of additional M subunit. The Type I RM systems are grouped into families, IA to IE, defined by complementation, hybridization and sequence similarity. The fusion protein forms an evolutionary intermediate form lying between the Type IA family of RM enzymes and the Type IB family of RM enzymes which have the frameshift located at a different part of the gene sequence.
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Affiliation(s)
- Gareth A Roberts
- EastChem School of Chemistry, The University of Edinburgh, The King's Buildings, Edinburgh, EH9 3JJ, UK
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Roberts GA, Stephanou AS, Kanwar N, Dawson A, Cooper LP, Chen K, Nutley M, Cooper A, Blakely GW, Dryden DTF. Exploring the DNA mimicry of the Ocr protein of phage T7. Nucleic Acids Res 2012; 40:8129-43. [PMID: 22684506 PMCID: PMC3439906 DOI: 10.1093/nar/gks516] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/07/2012] [Accepted: 05/09/2012] [Indexed: 11/30/2022] Open
Abstract
DNA mimic proteins have evolved to control DNA-binding proteins by competing with the target DNA for binding to the protein. The Ocr protein of bacteriophage T7 is the most studied DNA mimic and functions to block the DNA-binding groove of Type I DNA restriction/modification enzymes. This binding prevents the enzyme from cleaving invading phage DNA. Each 116 amino acid monomer of the Ocr dimer has an unusual amino acid composition with 34 negatively charged side chains but only 6 positively charged side chains. Extensive mutagenesis of the charges of Ocr revealed a regression of Ocr activity from wild-type activity to partial activity then to variants inactive in antirestriction but deleterious for cell viability and lastly to totally inactive variants with no deleterious effect on cell viability. Throughout the mutagenesis the Ocr mutant proteins retained their folding. Our results show that the extreme bias in charged amino acids is not necessary for antirestriction activity but that less charged variants can affect cell viability by leading to restriction proficient but modification deficient cell phenotypes.
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Affiliation(s)
- Gareth A. Roberts
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Augoustinos S. Stephanou
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Nisha Kanwar
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Angela Dawson
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Laurie P. Cooper
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Kai Chen
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Margaret Nutley
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Alan Cooper
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - Garry W. Blakely
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
| | - David T. F. Dryden
- EastChem School of Chemistry, School of Physics and Astronomy, The University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JZ, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JR, UK
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Zylicz-Stachula A, Zolnierkiewicz O, Lubys A, Ramanauskaite D, Mitkaite G, Bujnicki JM, Skowron PM. Related bifunctional restriction endonuclease-methyltransferase triplets: TspDTI, Tth111II/TthHB27I and TsoI with distinct specificities. BMC Mol Biol 2012; 13:13. [PMID: 22489904 PMCID: PMC3384240 DOI: 10.1186/1471-2199-13-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 04/10/2012] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND We previously defined a family of restriction endonucleases (REases) from Thermus sp., which share common biochemical and biophysical features, such as the fusion of both the nuclease and methyltransferase (MTase) activities in a single polypeptide, cleavage at a distance from the recognition site, large molecular size, modulation of activity by S-adenosylmethionine (SAM), and incomplete cleavage of the substrate DNA. Members include related thermophilic REases with five distinct specificities: TspGWI, TaqII, Tth111II/TthHB27I, TspDTI and TsoI. RESULTS TspDTI, TsoI and isoschizomers Tth111II/TthHB27I recognize different, but related sequences: 5'-ATGAA-3', 5'-TARCCA-3' and 5'-CAARCA-3' respectively. Their amino acid sequences are similar, which is unusual among REases of different specificity. To gain insight into this group of REases, TspDTI, the prototype member of the Thermus sp. enzyme family, was cloned and characterized using a recently developed method for partially cleaving REases. CONCLUSIONS TspDTI, TsoI and isoschizomers Tth111II/TthHB27I are closely related bifunctional enzymes. They comprise a tandem arrangement of Type I-like domains, like other Type IIC enzymes (those with a fusion of a REase and MTase domains), e.g. TspGWI, TaqII and MmeI, but their sequences are only remotely similar to these previously characterized enzymes. The characterization of TspDTI, a prototype member of this group, extends our understanding of sequence-function relationships among multifunctional restriction-modification enzymes.
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Taylor JE, Swiderska A, Artero JB, Callow P, Kneale G. Structural and functional analysis of the symmetrical Type I restriction endonuclease R.EcoR124I(NT). PLoS One 2012; 7:e35263. [PMID: 22493743 PMCID: PMC3320862 DOI: 10.1371/journal.pone.0035263] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 03/14/2012] [Indexed: 11/25/2022] Open
Abstract
Type I restriction-modification (RM) systems are comprised of two multi-subunit enzymes, the methyltransferase (∼160 kDa), responsible for methylation of DNA, and the restriction endonuclease (∼400 kDa), responsible for DNA cleavage. Both enzymes share a number of subunits. An engineered RM system, EcoR124I(NT), based on the N-terminal domain of the specificity subunit of EcoR124I was constructed that recognises the symmetrical sequence GAAN(7)TTC and is active as a methyltransferase. Here, we investigate the restriction endonuclease activity of R. EcoR124I(NT)in vitro and the subunit assembly of the multi-subunit enzyme. Finally, using small-angle neutron scattering and selective deuteration, we present a low-resolution structural model of the endonuclease and locate the motor subunits within the multi-subunit enzyme. We show that the covalent linkage between the two target recognition domains of the specificity subunit is not required for subunit assembly or enzyme activity, and discuss the implications for the evolution of Type I enzymes.
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Affiliation(s)
- James E. Taylor
- Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Anna Swiderska
- Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Jean-Baptiste Artero
- Partnership for Structural Biology, Institut Laue-Langevin, Grenoble, France
- Macromolecular Structure Research Group, Keele University, Keele, Staffordshire, United Kingdom
| | - Philip Callow
- Partnership for Structural Biology, Institut Laue-Langevin, Grenoble, France
| | - Geoff Kneale
- Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, United Kingdom
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Kennaway CK, Taylor JE, Song CF, Potrzebowski W, Nicholson W, White JH, Swiderska A, Obarska-Kosinska A, Callow P, Cooper LP, Roberts GA, Artero JB, Bujnicki JM, Trinick J, Kneale GG, Dryden DT. Structure and operation of the DNA-translocating type I DNA restriction enzymes. Genes Dev 2012; 26:92-104. [PMID: 22215814 PMCID: PMC3258970 DOI: 10.1101/gad.179085.111] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 11/14/2011] [Indexed: 11/24/2022]
Abstract
Type I DNA restriction/modification (RM) enzymes are molecular machines found in the majority of bacterial species. Their early discovery paved the way for the development of genetic engineering. They control (restrict) the influx of foreign DNA via horizontal gene transfer into the bacterium while maintaining sequence-specific methylation (modification) of host DNA. The endonuclease reaction of these enzymes on unmethylated DNA is preceded by bidirectional translocation of thousands of base pairs of DNA toward the enzyme. We present the structures of two type I RM enzymes, EcoKI and EcoR124I, derived using electron microscopy (EM), small-angle scattering (neutron and X-ray), and detailed molecular modeling. DNA binding triggers a large contraction of the open form of the enzyme to a compact form. The path followed by DNA through the complexes is revealed by using a DNA mimic anti-restriction protein. The structures reveal an evolutionary link between type I RM enzymes and type II RM enzymes.
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Affiliation(s)
- Christopher K. Kennaway
- Astbury Centre, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - James E. Taylor
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, United Kingdom
| | - Chun Feng Song
- Astbury Centre, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Wojciech Potrzebowski
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, PL-02-109 Warsaw, Poland
| | - William Nicholson
- Astbury Centre, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - John H. White
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom
| | - Anna Swiderska
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, United Kingdom
| | - Agnieszka Obarska-Kosinska
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, PL-02-109 Warsaw, Poland
| | - Philip Callow
- Partnership for Structural Biology, Institut Laue-Langevin, Grenoble, Cedex 9, France
| | - Laurie P. Cooper
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom
| | - Gareth A. Roberts
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom
| | - Jean-Baptiste Artero
- Partnership for Structural Biology, Institut Laue-Langevin, Grenoble, Cedex 9, France
- EPSAM and ISTM, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom
| | - Janusz M. Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, PL-02-109 Warsaw, Poland
- Bioinformatics Laboratory, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, PL-61-614 Poznan, Poland
| | - John Trinick
- Astbury Centre, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - G. Geoff Kneale
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, United Kingdom
| | - David T.F. Dryden
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom
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Kvist S, Narechania A, Oceguera-Figueroa A, Fuks B, Siddall ME. Phylogenomics of Reichenowia parasitica, an alphaproteobacterial endosymbiont of the freshwater leech Placobdella parasitica. PLoS One 2011; 6:e28192. [PMID: 22132238 PMCID: PMC3223239 DOI: 10.1371/journal.pone.0028192] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2011] [Accepted: 11/02/2011] [Indexed: 01/30/2023] Open
Abstract
Although several commensal alphaproteobacteria form close relationships with plant hosts where they aid in (e.g.,) nitrogen fixation and nodulation, only a few inhabit animal hosts. Among these, Reichenowia picta, R. ornata and R. parasitica, are currently the only known mutualistic, alphaproteobacterial endosymbionts to inhabit leeches. These bacteria are harbored in the epithelial cells of the mycetomal structures of their freshwater leech hosts, Placobdella spp., and these structures have no other obvious function than housing bacterial symbionts. However, the function of the bacterial symbionts has remained unclear. Here, we focused both on exploring the genomic makeup of R. parasitica and on performing a robust phylogenetic analysis, based on more data than previous hypotheses, to test its position among related bacteria. We sequenced a combined pool of host and symbiont DNA from 36 pairs of mycetomes and performed an in silico separation of the different DNA pools through subtractive scaffolding. The bacterial contigs were compared to 50 annotated bacterial genomes and the genome of the freshwater leech Helobdella robusta using a BLASTn protocol. Further, amino acid sequences inferred from the contigs were used as queries against the 50 bacterial genomes to establish orthology. A total of 358 orthologous genes were used for the phylogenetic analyses. In part, results suggest that R. parasitica possesses genes coding for proteins related to nitrogen fixation, iron/vitamin B translocation and plasmid survival. Our results also indicate that R. parasitica interacts with its host in part by transmembrane signaling and that several of its genes show orthology across Rhizobiaceae. The phylogenetic analyses support the nesting of R. parasitica within the Rhizobiaceae, as sister to a group containing Agrobacterium and Rhizobium species.
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Affiliation(s)
- Sebastian Kvist
- Richard Gilder Graduate School, American Museum of Natural History, New York, New York, United States of America
- Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, United States of America
| | - Apurva Narechania
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York, United States of America
| | - Alejandro Oceguera-Figueroa
- Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, United States of America
- Department of Biology, The Graduate Center, The City University of New York, New York, New York, United States of America
| | - Bella Fuks
- Long Island University Brooklyn Campus, Brooklyn, New York, United States of America
| | - Mark E. Siddall
- Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, United States of America
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York, United States of America
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Shen BW, Xu D, Chan SH, Zheng Y, Zhu Z, Xu SY, Stoddard BL. Characterization and crystal structure of the type IIG restriction endonuclease RM.BpuSI. Nucleic Acids Res 2011; 39:8223-36. [PMID: 21724614 PMCID: PMC3185434 DOI: 10.1093/nar/gkr543] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A type IIG restriction endonuclease, RM.BpuSI from Bacillus pumilus, has been characterized and its X-ray crystal structure determined at 2.35Å resolution. The enzyme is comprised of an array of 5-folded domains that couple the enzyme's N-terminal endonuclease domain to its C-terminal target recognition and methylation activities. The REase domain contains a PD-x15-ExK motif, is closely superimposable against the FokI endonuclease domain, and coordinates a single metal ion. A helical bundle domain connects the endonuclease and methyltransferase (MTase) domains. The MTase domain is similar to the N6-adenine MTase M.TaqI, while the target recognition domain (TRD or specificity domain) resembles a truncated S subunit of Type I R–M system. A final structural domain, that may form additional DNA contacts, interrupts the TRD. DNA binding and cleavage must involve large movements of the endonuclease and TRD domains, that are probably tightly coordinated and coupled to target site methylation status.
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Affiliation(s)
- Betty W Shen
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. A3-025, Seattle, WA 98109, USA
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Gao P, Tang Q, An X, Yan X, Liang D. Structure of HsdS subunit from Thermoanaerobacter tengcongensis sheds lights on mechanism of dynamic opening and closing of type I methyltransferase. PLoS One 2011; 6:e17346. [PMID: 21399684 PMCID: PMC3047542 DOI: 10.1371/journal.pone.0017346] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 01/29/2011] [Indexed: 11/25/2022] Open
Abstract
Type I DNA methyltransferases contain one specificity subunit (HsdS) and two modification subunits (HsdM). The electron microscopy model of M.EcoKI-M2S1 methyltransferase shows a reasonable closed state of this clamp-like enzyme, but the structure of the open state is still unclear. The 1.95 Å crystal structure of the specificity subunit from Thermoanaerobacter tengcongensis (TTE-HsdS) shows an unreported open form inter-domain orientation of this subunit. Based on the crystal structure of TTE-HsdS and the closed state model of M.EcoKI-M2S1, we constructed a potential open state model of type I methyltransferase. Mutational studies indicated that two α-helices (aa30-59 and aa466-495) of the TTE-HsdM subunit are important inter-subunit interaction sites in the TTE-M2S1 complex. DNA binding assays also highlighted the importance of the C-terminal region of TTE-HsdM for DNA binding by the TTE-M2S1 complex. On the basis of structural analysis, biochemical experiments and previous studies, we propose a dynamic opening and closing mechanism for type I methyltransferase.
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Affiliation(s)
- Pu Gao
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Qun Tang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - XiaoMin An
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - XiaoXue Yan
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- * E-mail: (XXY); (DCL)
| | - DongCai Liang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- * E-mail: (XXY); (DCL)
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