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Teklemariam AD, Al-Hindi RR, Qadri I, Alharbi MG, Ramadan WS, Ayubu J, Al-Hejin AM, Hakim RF, Hakim FF, Hakim RF, Alseraihi LI, Alamri T, Harakeh S. The Battle between Bacteria and Bacteriophages: A Conundrum to Their Immune System. Antibiotics (Basel) 2023; 12:381. [PMID: 36830292 PMCID: PMC9952470 DOI: 10.3390/antibiotics12020381] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Bacteria and their predators, bacteriophages, or phages are continuously engaged in an arms race for their survival using various defense strategies. Several studies indicated that the bacterial immune arsenal towards phage is quite diverse and uses different components of the host machinery. Most studied antiphage systems are associated with phages, whose genomic matter is double-stranded-DNA. These defense mechanisms are mainly related to either the host or phage-derived proteins and other associated structures and biomolecules. Some of these strategies include DNA restriction-modification (R-M), spontaneous mutations, blocking of phage receptors, production of competitive inhibitors and extracellular matrix which prevent the entry of phage DNA into the host cytoplasm, assembly interference, abortive infection, toxin-antitoxin systems, bacterial retrons, and secondary metabolite-based replication interference. On the contrary, phages develop anti-phage resistance defense mechanisms in consortium with each of these bacterial phage resistance strategies with small fitness cost. These mechanisms allow phages to undergo their replication safely inside their bacterial host's cytoplasm and be able to produce viable, competent, and immunologically endured progeny virions for the next generation. In this review, we highlight the major bacterial defense systems developed against their predators and some of the phage counterstrategies and suggest potential research directions.
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Affiliation(s)
- Addisu D. Teklemariam
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Rashad R. Al-Hindi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ishtiaq Qadri
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Mona G. Alharbi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Wafaa S. Ramadan
- Department of Anatomy, Faculty of Medicine (FM), King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Department of Anatomy, Faculty of Medicine, Ain Shams University, Cairo 11566, Egypt
| | - Jumaa Ayubu
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ahmed M. Al-Hejin
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Microbiology Level 2 Laboratory, King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | | | - Fanar F. Hakim
- Department of Internal Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Rahad F. Hakim
- Ibn Sina National College for Medical Studies, Jeddah 21418, Saudi Arabia
| | | | - Turki Alamri
- Family and Community Medicine Department, Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Steve Harakeh
- King Fahd Medical Research Center, Yousef Abdullatif Jameel Chair of Prophetic Medicine Application, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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Millman A, Bernheim A, Stokar-Avihail A, Fedorenko T, Voichek M, Leavitt A, Oppenheimer-Shaanan Y, Sorek R. Bacterial Retrons Function In Anti-Phage Defense. Cell 2020; 183:1551-1561.e12. [PMID: 33157039 DOI: 10.1016/j.cell.2020.09.065] [Citation(s) in RCA: 181] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/04/2020] [Accepted: 09/28/2020] [Indexed: 01/06/2023]
Abstract
Retrons are bacterial genetic elements comprised of a reverse transcriptase (RT) and a non-coding RNA (ncRNA). The RT uses the ncRNA as template, generating a chimeric RNA/DNA molecule in which the RNA and DNA components are covalently linked. Although retrons were discovered three decades ago, their function remained unknown. We report that retrons function as anti-phage defense systems. The defensive unit is composed of three components: the RT, the ncRNA, and an effector protein. We examined multiple retron systems and show that they confer defense against a broad range of phages via abortive infection. Focusing on retron Ec48, we show evidence that it "guards" RecBCD, a complex with central anti-phage functions in bacteria. Inhibition of RecBCD by phage proteins activates the retron, leading to abortive infection and cell death. Thus, the Ec48 retron forms a second line of defense that is triggered if the first lines of defense have collapsed.
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Affiliation(s)
- Adi Millman
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Aude Bernheim
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | - Taya Fedorenko
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Maya Voichek
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Azita Leavitt
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | - Rotem Sorek
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
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Abstract
Reverse transcriptases (RTs) are usually thought of as eukaryotic enzymes, but they are also present in bacteria and likely originated in bacteria and migrated to eukaryotes. Only three types of bacterial retroelements have been substantially characterized: group II introns, diversity-generating retroelements, and retrons. Recent work, however, has identified a myriad of uncharacterized RTs and RT-related sequences in bacterial genomes, which exhibit great sequence diversity and a range of domain structures. Apart from group II introns, none of these putative RTs show evidence of active retromobility. Instead, available information suggests that they are involved in useful processes, sometimes related to phages or phage resistance. This article reviews our knowledge of both characterized and uncharacterized RTs in bacteria. The range of their sequences and genomic contexts promises the discovery of new biochemical reactions and biological phenomena.
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Elfenbein JR, Knodler LA, Nakayasu ES, Ansong C, Brewer HM, Bogomolnaya L, Adams LG, McClelland M, Adkins JN, Andrews-Polymenis HL. Multicopy Single-Stranded DNA Directs Intestinal Colonization of Enteric Pathogens. PLoS Genet 2015; 11:e1005472. [PMID: 26367458 PMCID: PMC4569332 DOI: 10.1371/journal.pgen.1005472] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 07/28/2015] [Indexed: 01/10/2023] Open
Abstract
Multicopy single-stranded DNAs (msDNAs) are hybrid RNA-DNA molecules encoded on retroelements called retrons and produced by the action of retron reverse transcriptases. Retrons are widespread in bacteria but the natural function of msDNA has remained elusive despite 30 years of study. The major roadblock to elucidation of the function of these unique molecules has been the lack of any identifiable phenotypes for mutants unable to make msDNA. We report that msDNA of the zoonotic pathogen Salmonella Typhimurium is necessary for colonization of the intestine. Similarly, we observed a defect in intestinal persistence in an enteropathogenic E. coli mutant lacking its retron reverse transcriptase. Under anaerobic conditions in the absence of msDNA, proteins of central anaerobic metabolism needed for Salmonella colonization of the intestine are dysregulated. We show that the msDNA-deficient mutant can utilize nitrate, but not other alternate electron acceptors in anaerobic conditions. Consistent with the availability of nitrate in the inflamed gut, a neutrophilic inflammatory response partially rescued the ability of a mutant lacking msDNA to colonize the intestine. These findings together indicate that the mechanistic basis of msDNA function during Salmonella colonization of the intestine is proper production of proteins needed for anaerobic metabolism. We further conclude that a natural function of msDNA is to regulate protein abundance, the first attributable function for any msDNA. Our data provide novel insight into the function of this mysterious molecule that likely represents a new class of regulatory molecules.
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Affiliation(s)
- Johanna R. Elfenbein
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Leigh A. Knodler
- Paul G. Allen School of Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
| | - Ernesto S. Nakayasu
- Integrative Omics Group, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Charles Ansong
- Integrative Omics Group, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Heather M. Brewer
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Lydia Bogomolnaya
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
| | - L. Garry Adams
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Michael McClelland
- Department of Pathology and Laboratory Medicine, School of Medicine, University of California-Irvine, Irvine, California, United States of America
| | - Joshua N. Adkins
- Integrative Omics Group, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Helene L. Andrews-Polymenis
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
- * E-mail:
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Inouye K, Tanimoto S, Kamimoto M, Shimamoto T, Shimamoto T. Two novel retron elements are replaced with retron-Vc95 in Vibrio cholerae. Microbiol Immunol 2011; 55:510-3. [PMID: 21707739 DOI: 10.1111/j.1348-0421.2011.00342.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacterial reverse transcriptase (RT) is responsible for the production of an RNA-DNA complex called multicopy single-stranded DNA (msDNA). The genetic element required for the sysnthesis of msDNA is named a retron. Here, we characterize two novel retrons named retron-Vc81 and retron-Vc137 in Vibrio cholerae. Interestingly, retron-Vc81 and retron-Vc137 are replaced by retron-Vc95 at the same location on the chromosome.
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Affiliation(s)
- Kumiko Inouye
- Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan
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Simon DM, Zimmerly S. A diversity of uncharacterized reverse transcriptases in bacteria. Nucleic Acids Res 2008; 36:7219-29. [PMID: 19004871 PMCID: PMC2602772 DOI: 10.1093/nar/gkn867] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Retroelements are usually considered to be eukaryotic elements because of the large number and variety in eukaryotic genomes. By comparison, reverse transcriptases (RTs) are rare in bacteria, with only three characterized classes: retrons, group II introns and diversity-generating retroelements (DGRs). Here, we present the results of a bioinformatic survey that aims to define the landscape of RTs across eubacterial, archaeal and phage genomes. We identify and categorize 1021 RTs, of which the majority are group II introns (73%). Surprisingly, a plethora of novel RTs are found that do not belong to characterized classes. The RTs have 11 domain architectures and are classified into 20 groupings based on sequence similarity, phylogenetic analyses and open reading frame domain structures. Interestingly, group II introns are the only bacterial RTs to exhibit clear evidence for independent mobility, while five other groups have putative functions in defense against phage infection or promotion of phage infection. These examples suggest that additional beneficial functions will be discovered among uncharacterized RTs. The study lays the groundwork for experimental characterization of these highly diverse sequences and has implications for the evolution of retroelements.
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Affiliation(s)
- Dawn M Simon
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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Tourasse NJ, Kolstø AB. Survey of group I and group II introns in 29 sequenced genomes of the Bacillus cereus group: insights into their spread and evolution. Nucleic Acids Res 2008; 36:4529-48. [PMID: 18587153 PMCID: PMC2504315 DOI: 10.1093/nar/gkn372] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Group I and group II introns are different catalytic self-splicing and mobile RNA elements that contribute to genome dynamics. In this study, we have analyzed their distribution and evolution in 29 sequenced genomes from the Bacillus cereus group of bacteria. Introns were of different structural classes and evolutionary origins, and a large number of nearly identical elements are shared between multiple strains of different sources, suggesting recent lateral transfers and/or that introns are under a strong selection pressure. Altogether, 73 group I introns were identified, inserted in essential genes from the chromosome or newly described prophages, including the first elements found within phages in bacterial plasmids. Notably, bacteriophages are an important source for spreading group I introns between strains. Furthermore, 77 group II introns were found within a diverse set of chromosomal and plasmidic genes. Unusual findings include elements located within conserved DNA metabolism and repair genes and one intron inserted within a novel retroelement. Group II introns are mainly disseminated via plasmids and can subsequently invade the host genome, in particular by coupling mobility with host cell replication. This study reveals a very high diversity and variability of mobile introns in B. cereus group strains.
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Affiliation(s)
- Nicolas J Tourasse
- Laboratory for Microbial Dynamics (LaMDa), Department of Pharmaceutical Biosciences, University of Oslo, Oslo, Norway
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Affiliation(s)
- Elena Zelin
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
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Lampson BC, Inouye M, Inouye S. Retrons, msDNA, and the bacterial genome. Cytogenet Genome Res 2005; 110:491-9. [PMID: 16093702 DOI: 10.1159/000084982] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Accepted: 10/16/2003] [Indexed: 12/23/2022] Open
Abstract
Retrons are distinct DNA sequences that code for a reverse transcriptase (RT) similar to the RTs produced by retroviruses and other types of retroelements. Retron DNAs are commonly associated with prophage DNA and are found in the genomes of a wide variety of different bacteria. The retron RT is used to synthesize a strange satellite DNA known as msDNA. msDNA is actually a complex of DNA, RNA, and probably protein. It is composed of a small, single-stranded DNA, linked to a small, single-stranded RNA molecule. The 5' end of the DNA molecule is joined to an internal guanosine residue of the RNA molecule by a unique 2'-5' phosphodiester bond. msDNA is produced in many hundreds of copies per cell, but its function remains unknown. Although retrons are absent from the genome of most members of a population of related bacteria, retrons may not be entirely benign DNAs. Evidence is beginning to suggest that retron elements may produce small but potentially significant effects on the host cell. This includes the generation of repeated copies of the msDNA sequence in the genome, and increasing the frequency of spontaneous mutations. Because these events involve the retron RT, this may represent a source of reverse transcription in the bacterial cell. Thus, the process of reverse transcription, a force that has profoundly affected the content and structure of most eukaryotic genomes, may likewise be responsible for changes in some prokaryotic genomes.
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Affiliation(s)
- B C Lampson
- Department of Health Sciences, East Tennessee State University, Johnson City, TN, USA
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Vellore J, Moretz SE, Lampson BC. A group II intron-type open reading frame from the thermophile Bacillus (Geobacillus) stearothermophilus encodes a heat-stable reverse transcriptase. Appl Environ Microbiol 2005; 70:7140-7. [PMID: 15574910 PMCID: PMC535183 DOI: 10.1128/aem.70.12.7140-7147.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The production of a stable cDNA copy of an unstable RNA molecule by reverse transcription is a widely used and essential technology for many important applications, such as the construction of gene libraries, production of DNA probes, and analysis of gene expression by reverse transcriptase PCR (RT-PCR). However, the synthesis of full-length cDNAs is frequently inefficient, because the RT commonly used often produces truncated cDNAs. Synthesizing cDNA at higher temperatures, on the other hand, can provide a number of improvements. These include increasing the length of cDNA product, greater accuracy, and greater specificity during reverse transcription. Thus, an RT that remains stable and active at hot temperatures may produce better-quality cDNAs and improve the yield of full-length cDNAs. Described here is the discovery of a gene, designated trt, from the genome of the thermophilic bacterium Bacillus (Geobacillus) stearothermophilus strain 10. The gene codes for an open reading frame (ORF) similar to the ORFs encoded by group II introns found in bacteria. The gene was cloned and overexpressed in Escherichia coli, and its protein product was partially purified. Like the host organism, the Trt protein is a heat-stable protein with RT activity and can reverse transcribe RNA at temperatures as high as 75 degrees C.
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Affiliation(s)
- Jaishree Vellore
- Department of Health Sciences, East Tennessee State University, Johnson City, TN 37614, USA
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Chen Y, McMicken HW. Intracellular production of DNA enzyme by a novel single-stranded DNA expression vector. Gene Ther 2003; 10:1776-80. [PMID: 12939644 DOI: 10.1038/sj.gt.3302068] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A set of single-stranded DNA (ssDNA) expression vectors, which can generate intracellularly any ssDNA or oligodeoxynucleotide (ODN) molecules, have been developed in our laboratory. Studies from our laboratory as well as our collaborators demonstrated that these ssDNA expression vectors are capable of producing: (1) 10-23 DNA enzyme for downregulating c-raf kinase gene expression and (2) triplex-forming oligodeoxynucleotide (TFO) for inducing genomic recombination. We report here the construction of a new version of ssDNA expression vector. A beta-galactosidase (beta-gal) reporter gene was used as a test target so that the alteration of gene expression can be easily measured using beta-gal activity assay. We designed a 10-23 DNA enzyme molecule that specifically cleaves beta-gal mRNA at protein translation starting site (ATG). Using a cell-free RNA cleavage assay, we confirmed that this DNA enzyme molecule could effectively cleave beta-gal RNA. However, a single substitution from T to G in the catalytic domain of this DNA enzyme molecule abolished its RNA cleavage activity. We also constructed an expression vector that can generate DNA enzyme molecules in cells. A549 lung carcinoma cells were cotransfected with both DNA enzyme expression vector and the beta-gal reporter gene. Compared to the cells that were transfected with the mutated DNA enzyme expression vector, significant reduction of beta-gal gene expression (up to 76%) was observed in the cells transfected with DNA enzyme expression vector as indicated by the protein expression level as well as its enzyme activity. These results further suggest that the ssDNA expression vector has potential applications in the study of gene function and target validation.
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Affiliation(s)
- Y Chen
- CytoGenix, Inc., Houston, TX 77099, USA
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Matiasovicova J, Faldynova M, Pravcova M, Karpiskova R, Kolackova I, Damborsky J, Rychlik I. Retron reverse transcriptase rrtT is ubiquitous in strains of Salmonella enterica serovar Typhimurium. FEMS Microbiol Lett 2003; 223:281-6. [PMID: 12829299 DOI: 10.1016/s0378-1097(03)00398-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Bacterial retron reverse transcriptases are unusual enzymes which utilise the same RNA molecule as a template and also as a primer for initiation of the reverse transcription. Except for their relatively frequent presence in Myxococcus spp., they are considered as quite rare proteins. However, in this study we proved that retron reverse transcriptase is frequently found in certain serovars of Salmonella enterica. Using polymerase chain reaction (PCR), in strains of serovar Typhimurium, the rrtT (retron reverse transcriptase Typhimurium) gene was detected in 158 out of 175 tested field strains. On the other hand, in none of the 18 tested serovar Enteritidis strains the rrtT was detected in their genome. Detailed computer analysis allowed us to predict the sequence of msDNA and to propose that the final msDNA is free of any RNA. Furthermore, we predict that there are at least three different classes of retron reverse transcriptases.
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Lampson BC, Xu C, Rice SA, Inouye S. A partial copy of msDNA from a new retron element is likely a retrotransposed DNA found in the myxobacterium Nannocystis exedens. Gene 2002; 299:251-61. [PMID: 12459273 DOI: 10.1016/s0378-1119(02)00977-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Retrons are reverse transcriptase (RT) encoding genetic elements usually located on the chromosome of a wide variety of mostly Gram-negative bacteria. Here we describe a new retron, designated Ne144, found in the chromosome of the myxobacterium Nannocystis exedens. This element codes for a 515-amino-acid RT that is most closely related to those found in other myxobacterial retrons. The RT is responsible for the production of a small satellite DNA called msDNA. This msDNA is composed of a 144 base, single-stranded DNA that is linked to a 72 base single-stranded RNA. The RNA strand is joined to the 5' end of the DNA chain via a 2'-5' linkage that occurs from the 2' position of an internal guanosine residue in the RNA. In addition to the retron element, the chromosome of N. exedens also contains several partial copies of the msDNA sequence as revealed by DNA hybridization experiments using msDNA as a probe. One of these partial copies was characterized from a chromosome restriction fragment and found to contain a sequence that matches the last 82 bases of the DNA strand and five bases of the RNA strand in msDNA-Ne144. This partial copy of msDNA is very likely a retrotransposed sequence that was generated by reverse transcription using an RNA (the primer-template RNA for msDNA) as a template and the 3' end of a nick in the chromosome as a primer, followed by incorporation into an open reading frame. The presence of this truncated copy of msDNA is strong evidence of retrotransposition in N. exedens causing an alteration in the bacterial genome.
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Affiliation(s)
- Bert C Lampson
- Department of Health Sciences, East Tennessee State University, Johnson City, TN 37614, USA
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