1
|
Evseev PV, Shneider MM, Kolupaeva LV, Kasimova AA, Timoshina OY, Perepelov AV, Shpirt AM, Shelenkov AA, Mikhailova YV, Suzina NE, Knirel YA, Miroshnikov KA, Popova AV. New Obolenskvirus Phages Brutus and Scipio: Biology, Evolution, and Phage-Host Interaction. Int J Mol Sci 2024; 25:2074. [PMID: 38396752 PMCID: PMC10888812 DOI: 10.3390/ijms25042074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Two novel virulent phages of the genus Obolenskvirus infecting Acinetobacter baumannii, a significant nosocomial pathogen, have been isolated and studied. Phages Brutus and Scipio were able to infect A. baumannii strains belonging to the K116 and K82 capsular types, respectively. The biological properties and genomic organization of the phages were characterized. Comparative genomic, phylogenetic, and pangenomic analyses were performed to investigate the relationship of Brutus and Scipio to other bacterial viruses and to trace the possible origin and evolutionary history of these phages and other representatives of the genus Obolenskvirus. The investigation of enzymatic activity of the tailspike depolymerase encoded in the genome of phage Scipio, the first reported virus infecting A. baumannii of the K82 capsular type, was performed. The study of new representatives of the genus Obolenskvirus and mechanisms of action of depolymerases encoded in their genomes expands knowledge about the diversity of viruses within this taxonomic group and strategies of Obolenskvirus-host bacteria interaction.
Collapse
Affiliation(s)
- Peter V. Evseev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (M.M.S.); (O.Y.T.); (K.A.M.)
- State Research Center for Applied Microbiology and Biotechnology, City District Serpukhov, Moscow Region, 142279 Obolensk, Russia; (L.V.K.); (A.A.K.)
- Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Mikhail M. Shneider
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (M.M.S.); (O.Y.T.); (K.A.M.)
| | - Lyubov V. Kolupaeva
- State Research Center for Applied Microbiology and Biotechnology, City District Serpukhov, Moscow Region, 142279 Obolensk, Russia; (L.V.K.); (A.A.K.)
| | - Anastasia A. Kasimova
- State Research Center for Applied Microbiology and Biotechnology, City District Serpukhov, Moscow Region, 142279 Obolensk, Russia; (L.V.K.); (A.A.K.)
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia; (A.V.P.); (A.M.S.); (Y.A.K.)
| | - Olga Y. Timoshina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (M.M.S.); (O.Y.T.); (K.A.M.)
| | - Andrey V. Perepelov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia; (A.V.P.); (A.M.S.); (Y.A.K.)
| | - Anna M. Shpirt
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia; (A.V.P.); (A.M.S.); (Y.A.K.)
| | - Andrey A. Shelenkov
- Central Scientific Research Institute of Epidemiology, 111123 Moscow, Russia (Y.V.M.)
| | - Yulia V. Mikhailova
- Central Scientific Research Institute of Epidemiology, 111123 Moscow, Russia (Y.V.M.)
| | - Natalia E. Suzina
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Center for Biological Research of the Russian Academy of Sciences”, Moscow Region, 142290 Pushchino, Russia;
| | - Yuriy A. Knirel
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia; (A.V.P.); (A.M.S.); (Y.A.K.)
| | - Konstantin A. Miroshnikov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (M.M.S.); (O.Y.T.); (K.A.M.)
| | - Anastasia V. Popova
- State Research Center for Applied Microbiology and Biotechnology, City District Serpukhov, Moscow Region, 142279 Obolensk, Russia; (L.V.K.); (A.A.K.)
| |
Collapse
|
2
|
Bari SMN, Chou-Zheng L, Howell O, Hossain M, Hill CM, Boyle TA, Cater K, Dandu VS, Thomas A, Aslan B, Hatoum-Aslan A. A unique mode of nucleic acid immunity performed by a multifunctional bacterial enzyme. Cell Host Microbe 2022; 30:570-582.e7. [PMID: 35421352 DOI: 10.1016/j.chom.2022.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/10/2021] [Accepted: 03/01/2022] [Indexed: 11/24/2022]
Abstract
The perpetual arms race between bacteria and their viruses (phages) has given rise to diverse immune systems, including restriction-modification and CRISPR-Cas, which sense and degrade phage-derived nucleic acids. These complex systems rely upon production and maintenance of multiple components to achieve antiphage defense. However, the prevalence and effectiveness of minimal, single-component systems that cleave DNA remain unknown. Here, we describe a unique mode of nucleic acid immunity mediated by a single enzyme with nuclease and helicase activities, herein referred to as Nhi (nuclease-helicase immunity). This enzyme provides robust protection against diverse staphylococcal phages and prevents phage DNA accumulation in cells stripped of all other known defenses. Our observations support a model in which Nhi targets and degrades phage-specific replication intermediates. Importantly, Nhi homologs are distributed in diverse bacteria and exhibit functional conservation, highlighting the versatility of such compact weapons as major players in antiphage defense.
Collapse
Affiliation(s)
- S M Nayeemul Bari
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA
| | - Lucy Chou-Zheng
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA
| | - Olivia Howell
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA
| | - Motaher Hossain
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA
| | - Courtney M Hill
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA
| | - Tori A Boyle
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA
| | - Katie Cater
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Vidya Sree Dandu
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Alexander Thomas
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Barbaros Aslan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA
| | - Asma Hatoum-Aslan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61821, USA.
| |
Collapse
|
3
|
LeGault KN, Barth ZK, DePaola P, Seed KD. A phage parasite deploys a nicking nuclease effector to inhibit viral host replication. Nucleic Acids Res 2022; 50:8401-8417. [PMID: 35066583 PMCID: PMC9410903 DOI: 10.1093/nar/gkac002] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 12/17/2021] [Accepted: 01/12/2022] [Indexed: 12/11/2022] Open
Abstract
PLEs (phage-inducible chromosomal island-like elements) are phage parasites integrated into the chromosome of epidemic Vibrio cholerae. In response to infection by its viral host ICP1, PLE excises, replicates and hijacks ICP1 structural components for transduction. Through an unknown mechanism, PLE prevents ICP1 from transitioning to rolling circle replication (RCR), a prerequisite for efficient packaging of the viral genome. Here, we characterize a PLE-encoded nuclease, NixI, that blocks phage development likely by nicking ICP1’s genome as it transitions to RCR. NixI-dependent cleavage sites appear in ICP1’s genome during infection of PLE(+) V. cholerae. Purified NixI demonstrates in vitro nuclease activity specifically for sites in ICP1’s genome and we identify a motif that is necessary for NixI-mediated cleavage. Importantly, NixI is sufficient to limit ICP1 genome replication and eliminate progeny production, representing the most inhibitory PLE-encoded mechanism revealed to date. We identify distant NixI homologs in an expanded family of putative phage parasites in vibrios that lack nucleotide homology to PLEs but nonetheless share genomic synteny with PLEs. More generally, our results reveal a previously unknown mechanism deployed by phage parasites to limit packaging of their viral hosts’ genome and highlight the prominent role of nuclease effectors as weapons in the arms race between antagonizing genomes.
Collapse
Affiliation(s)
- Kristen N LeGault
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Peter DePaola
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA.,Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| |
Collapse
|
4
|
Neamah MM, Mir-Sanchis I, López-Sanz M, Acosta S, Baquedano I, Haag AF, Marina A, Ayora S, Penadés JR. Sak and Sak4 recombinases are required for bacteriophage replication in Staphylococcus aureus. Nucleic Acids Res 2017; 45:6507-6519. [PMID: 28475766 PMCID: PMC5499656 DOI: 10.1093/nar/gkx308] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 05/03/2017] [Indexed: 11/16/2022] Open
Abstract
DNA-single strand annealing proteins (SSAPs) are recombinases frequently encoded in the genome of many bacteriophages. As SSAPs can promote homologous recombination among DNA substrates with an important degree of divergence, these enzymes are involved both in DNA repair and in the generation of phage mosaicisms. Here, analysing Sak and Sak4 as representatives of two different families of SSAPs present in phages infecting the clinically relevant bacterium Staphylococcus aureus, we demonstrate for the first time that these enzymes are absolutely required for phage reproduction. Deletion of the genes encoding these enzymes significantly reduced phage replication and the generation of infectious particles. Complementation studies revealed that these enzymes are required both in the donor (after prophage induction) and in the recipient strain (for infection). Moreover, our results indicated that to perform their function SSAPs require the activity of their cognate single strand binding (Ssb) proteins. Mutational studies demonstrated that the Ssb proteins are also required for phage replication, both in the donor and recipient strain. In summary, our results expand the functions attributed to the Sak and Sak4 proteins, and demonstrate that both SSAPs and Ssb proteins are essential for the life cycle of temperate staphylococcal phages.
Collapse
Affiliation(s)
- Maan M Neamah
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.,Department of Microbiology, Faculty of Veterinary Medicine, University of Kufa, Kufa, Iraq
| | - Ignacio Mir-Sanchis
- Departamento de Ciencias Biomédicas, Universidad CEU Cardenal Herrera, 46113 Moncada, Valencia, Spain
| | - María López-Sanz
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 28049 Madrid, Spain
| | - Sonia Acosta
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 28049 Madrid, Spain
| | - Ignacio Baquedano
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 28049 Madrid, Spain
| | - Andreas F Haag
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Alberto Marina
- Instituto de Biomedicina de Valencia (IBV-CSIC) and CIBER de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Silvia Ayora
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 28049 Madrid, Spain
| | - José R Penadés
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| |
Collapse
|
5
|
Hulo C, Masson P, Toussaint A, Osumi-Sutherland D, de Castro E, Auchincloss AH, Poux S, Bougueleret L, Xenarios I, Le Mercier P. Bacterial Virus Ontology; Coordinating across Databases. Viruses 2017; 9:E126. [PMID: 28545254 PMCID: PMC5490803 DOI: 10.3390/v9060126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 12/29/2022] Open
Abstract
Bacterial viruses, also called bacteriophages, display a great genetic diversity and utilize unique processes for infecting and reproducing within a host cell. All these processes were investigated and indexed in the ViralZone knowledge base. To facilitate standardizing data, a simple ontology of viral life-cycle terms was developed to provide a common vocabulary for annotating data sets. New terminology was developed to address unique viral replication cycle processes, and existing terminology was modified and adapted. Classically, the viral life-cycle is described by schematic pictures. Using this ontology, it can be represented by a combination of successive events: entry, latency, transcription/replication, host-virus interactions and virus release. Each of these parts is broken down into discrete steps. For example enterobacteria phage lambda entry is broken down in: viral attachment to host adhesion receptor, viral attachment to host entry receptor, viral genome ejection and viral genome circularization. To demonstrate the utility of a standard ontology for virus biology, this work was completed by annotating virus data in the ViralZone, UniProtKB and Gene Ontology databases.
Collapse
Affiliation(s)
- Chantal Hulo
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| | - Patrick Masson
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| | - Ariane Toussaint
- University Libre de Bruxelles, Génétique et Physiologie Bactérienne (LGPB), 12 rue des Professeurs Jeener et Brachet, 6041 Charleroi, Belgium.
| | - David Osumi-Sutherland
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton CB10 1SD, UK.
| | - Edouard de Castro
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| | - Andrea H Auchincloss
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| | - Sylvain Poux
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| | - Lydie Bougueleret
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| | - Ioannis Xenarios
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| | - Philippe Le Mercier
- Swiss-Prot group, SIB Swiss Institute of Bioinformatics, CMU, University of Geneva Medical School, 1211 Geneva, Switzerland.
| |
Collapse
|
6
|
Kozłowska KI, Tymecka-Mulik J, Węgrzyn G. Purified Stx and λ phage initiator O proteins bind specifically to two different origins of replication in vitro. Protein Expr Purif 2016; 131:16-26. [PMID: 27826079 DOI: 10.1016/j.pep.2016.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/24/2016] [Accepted: 11/04/2016] [Indexed: 12/26/2022]
Abstract
The O protein is a crucial factor initiating the DNA replication of lambdoid bacteriophage. Efficient DNA replication of Shiga toxin-converting phage is necessary for effective production of Shiga toxin - main virulence factor of STEC strains. We developed an improved protocol for overproduction, bacterial cell lysis and purification of λO protein. With use of this method we have also isolated O proteins of Stx-phage P27 and 933W that were never purified before. Purified proteins were tested for their DNA binding activity and revealed a sequence specific interactions.
Collapse
Affiliation(s)
- Katarzyna I Kozłowska
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdańsk, Poland.
| | - Joanna Tymecka-Mulik
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdańsk, Poland
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdańsk, Poland
| |
Collapse
|
7
|
Casjens SR, Hendrix RW. Bacteriophage lambda: Early pioneer and still relevant. Virology 2015; 479-480:310-30. [PMID: 25742714 PMCID: PMC4424060 DOI: 10.1016/j.virol.2015.02.010] [Citation(s) in RCA: 173] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/13/2015] [Accepted: 02/05/2015] [Indexed: 12/14/2022]
Abstract
Molecular genetic research on bacteriophage lambda carried out during its golden age from the mid-1950s to mid-1980s was critically important in the attainment of our current understanding of the sophisticated and complex mechanisms by which the expression of genes is controlled, of DNA virus assembly and of the molecular nature of lysogeny. The development of molecular cloning techniques, ironically instigated largely by phage lambda researchers, allowed many phage workers to switch their efforts to other biological systems. Nonetheless, since that time the ongoing study of lambda and its relatives has continued to give important new insights. In this review we give some relevant early history and describe recent developments in understanding the molecular biology of lambda's life cycle.
Collapse
Affiliation(s)
- Sherwood R Casjens
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Emma Eccles Jones Medical Research Building, 15 North Medical Drive East, Salt Lake City, UT 84112, USA; Biology Department, University of Utah, Salt Lake City, UT 84112, USA.
| | - Roger W Hendrix
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| |
Collapse
|
8
|
Genome segregation and packaging machinery in Acanthamoeba polyphaga mimivirus is reminiscent of bacterial apparatus. J Virol 2014; 88:6069-75. [PMID: 24623441 DOI: 10.1128/jvi.03199-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Genome packaging is a critical step in the virion assembly process. The putative ATP-driven genome packaging motor of Acanthamoeba polyphaga mimivirus (APMV) and other nucleocytoplasmic large DNA viruses (NCLDVs) is a distant ortholog of prokaryotic chromosome segregation motors, such as FtsK and HerA, rather than other viral packaging motors, such as large terminase. Intriguingly, APMV also encodes other components, i.e., three putative serine recombinases and a putative type II topoisomerase, all of which are essential for chromosome segregation in prokaryotes. Based on our analyses of these components and taking the limited available literature into account, here we propose for the first time a model for genome segregation and packaging in APMV that can possibly be extended to NCLDV subfamilies, except perhaps Poxviridae and Ascoviridae. This model might represent a unique variation of the prokaryotic system acquired and contrived by the large DNA viruses of eukaryotes. It is also consistent with previous observations that unicellular eukaryotes, such as amoebae, are melting pots for the advent of chimeric organisms with novel mechanisms. IMPORTANCE Extremely large viruses with DNA genomes infect a wide range of eukaryotes, from human beings to amoebae and from crocodiles to algae. These large DNA viruses, unlike their much smaller cousins, have the capability of making most of the protein components required for their multiplication. Once they infect the cell, these viruses set up viral replication centers, known as viral factories, to carry out their multiplication with very little help from the host. Our sequence analyses show that there is remarkable similarity between prokaryotes (bacteria and archaea) and large DNA viruses, such as mimivirus, vaccinia virus, and pandoravirus, in the way that they process their newly synthesized genetic material to make sure that only one copy of the complete genome is generated and is meticulously placed inside the newly synthesized viral particle. These findings have important evolutionary implications about the origin and evolution of large viruses.
Collapse
|
9
|
Olszewski P, Szambowska A, Barałska S, Narajczyk M, Węgrzyn G, Glinkowska M. A dual promoter system regulating λ DNA replication initiation. Nucleic Acids Res 2014; 42:4450-62. [PMID: 24500197 PMCID: PMC3985674 DOI: 10.1093/nar/gku103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Transcription and DNA replication are tightly regulated to ensure coordination of gene expression with growth conditions and faithful transmission of genetic material to progeny. A large body of evidence has accumulated, indicating that encounters between protein machineries carrying out DNA and RNA synthesis occur in vivo and may have important regulatory consequences. This feature may be exacerbated in the case of compact genomes, like the one of bacteriophage λ, used in our study. Transcription that starts at the rightward pR promoter and proceeds through the λ origin of replication and downstream of it was proven to stimulate the initiation of λ DNA replication. Here, we demonstrate that the activity of a convergently oriented pO promoter decreases the efficiency of transcription starting from pR. Our results show, however, that a lack of the functional pO promoter negatively influences λ phage and λ-derived plasmid replication. We present data, suggesting that this effect is evoked by the enhanced level of the pR-driven transcription, occurring in the presence of the defective pO, which may result in the impeded formation of the replication initiation complex. Our data suggest that the cross talk between the two promoters regulates λ DNA replication and coordinates transcription and replication processes.
Collapse
Affiliation(s)
- Paweł Olszewski
- Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland, Laboratory of Molecular Biology (affiliated with the University of Gdańsk), Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Wita Stwosza 59, 80-308 Gdańsk, Poland and Laboratory of Electron Microscopy, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | | | | | | | | | | |
Collapse
|
10
|
Abstract
Bacteriophage λ, rediscovered in the early 1950s, has served as a model in molecular biology studies for decades. Although currently more complex organisms and more complicated biological systems can be studied, this phage is still an excellent model to investigate principles of biological processes occurring at the molecular level. In fact, very few other biological models provide possibilities to examine regulations of biological mechanisms as detailed as performed with λ. In this chapter, recent advances in our understanding of mechanisms of bacteriophage λ development are summarized and discussed. Particularly, studies on (i) phage DNA injection, (ii) molecular bases of the lysis-versus-lysogenization decision and the lysogenization process itself, (iii) prophage maintenance and induction, (iv), λ DNA replication, (v) phage-encoded recombination systems, (vi) transcription antitermination, (vii) formation of the virion structure, and (viii) lysis of the host cell, as published during several past years, will be presented.
Collapse
|
11
|
Recombination-dependent concatemeric viral DNA replication. Virus Res 2011; 160:1-14. [PMID: 21708194 DOI: 10.1016/j.virusres.2011.06.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 06/07/2011] [Accepted: 06/10/2011] [Indexed: 11/24/2022]
Abstract
The initiation of viral double stranded (ds) DNA replication involves proteins that recruit and load the replisome at the replication origin (ori). Any block in replication fork progression or a programmed barrier may act as a factor for ori-independent remodelling and assembly of a new replisome at the stalled fork. Then replication initiation becomes dependent on recombination proteins, a process called recombination-dependent replication (RDR). RDR, which is recognized as being important for replication restart and stability in all living organisms, plays an essential role in the replication cycle of many dsDNA viruses. The SPP1 virus, which infects Bacillus subtilis cells, serves as a paradigm to understand the links between replication and recombination in circular dsDNA viruses. SPP1-encoded initiator and replisome assembly proteins control the onset of viral replication and direct the recruitment of host-encoded replisomal components at viral oriL. SPP1 uses replication fork reactivation to switch from ori-dependent θ-type (circle-to-circle) replication to σ-type RDR. Replication fork arrest leads to a double strand break that is processed by viral-encoded factors to generate a D-loop into which a new replisome is assembled, leading to σ-type viral replication. SPP1 RDR proteins are compared with similar proteins encoded by other viruses and their possible in vivo roles are discussed.
Collapse
|
12
|
Szambowska A, Pierechod M, Wegrzyn G, Glinkowska M. Coupling of transcription and replication machineries in λ DNA replication initiation: evidence for direct interaction of Escherichia coli RNA polymerase and the λO protein. Nucleic Acids Res 2010; 39:168-77. [PMID: 20833633 PMCID: PMC3017604 DOI: 10.1093/nar/gkq752] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transcription proceeding downstream of the λ phage replication origin was previously shown to support initial steps of the λ primosome assembly in vitro and to regulate frequency and directionality of λ DNA replication in vivo. In this report, the data are presented indicating that the RNA polymerase β subunit makes a direct contact with the λO protein, a replication initiator of λ phage. These results suggest that the role of RNA polymerase during the initiation of λ phage DNA replication may be more complex than solely influencing DNA topology. Results demonstrated in this study also show that gyrase supercoiling activity stimulates the formation of a complex between λO and RNA polymerase, suggesting that the introduction of negative supercoils by DNA gyrase, besides lowering the energy required for DNA strand separation, may play an additional role in modeling protein–protein interactions at early steps of DNA replication initiation.
Collapse
Affiliation(s)
- Anna Szambowska
- Laboratory of Molecular Biology (affiliated with the University of Gdańsk), Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Gdańsk, Poland
| | | | | | | |
Collapse
|
13
|
Abstract
Papillomaviruses establish persistent infection in the dividing, basal epithelial cells of the host. The viral genome is maintained as a circular, double-stranded DNA, extrachromosomal element within these cells. Viral genome amplification occurs only when the epithelial cells differentiate and viral particles are shed in squames that are sloughed from the surface of the epithelium. There are three modes of replication in the papillomavirus life cycle. Upon entry, in the establishment phase, the viral genome is amplified to a low copy number. In the second maintenance phase, the genome replicates in dividing cells at a constant copy number, in synchrony with the cellular DNA. And finally, in the vegetative or productive phase, the viral DNA is amplified to a high copy number in differentiated cells and is destined to be packaged in viral capsids. This review discusses the cis elements and protein factors required for each stage of papillomavirus replication.
Collapse
Affiliation(s)
- Alison A McBride
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
14
|
Szalewska-Palasz A, Wegrzyn G, Wegrzyn A. Mechanisms of physiological regulation of RNA synthesis in bacteria: new discoveries breaking old schemes. J Appl Genet 2007; 48:281-94. [PMID: 17666783 DOI: 10.1007/bf03195225] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Although in bacterial cells all genes are transcribed by RNA polymerase, there are 2 additional enzymes capable of catalyzing RNA synthesis: poly(A) polymerase I, which adds poly(A) residues to transcripts, and primase, which produces primers for DNA replication. Mechanisms of actions of these 3 RNA-synthesizing enzymes were investigated for many years, and schemes of their regulations have been proposed and generally accepted. Nevertheless, recent discoveries indicated that apart from well-understood mechanisms, there are additional regulatory processes, beyond the established schemes, which allow bacterial cells to respond to changing environmental and physiological conditions. These newly discovered mechanisms, which are discussed in this review, include: (i) specific regulation of gene expression by RNA polyadenylation, (ii) control of DNA replication by interactions of the starvation alarmones, guanosine pentaphosphate and guanosine tetraphosphate, (p)ppGpp, with DnaG primase, (iii) a role for the DksA protein in ppGpp-mediated regulation of transcription, (iv) allosteric modulation of the RNA polymerase catalytic reaction by specific inhibitors of transcription, rifamycins, (v) stimulation of transcription initiation by proteins binding downstream of the promoter sequences, and (vi) promoter-dependent control of transcription antitermination efficiency.
Collapse
|