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Beck J, Biechele M, Repik C, Gruber P, Furtmüller PG, Hahn R. Desorption of plasmid DNA from anion exchangers: Salt concentration at elution is independent of plasmid size and load. J Sep Sci 2023; 46:e2200943. [PMID: 36807776 DOI: 10.1002/jssc.202200943] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 02/20/2023]
Abstract
Detailed studies on the sorption behavior of plasmids on anion exchangers are rare compared to proteins. In this study, we systematically compare the elution behavior of plasmid DNA on three common anion exchange resins using linear gradient and isocratic elution experiments. Two plasmids of different lengths, 8 and 20 kbp, were studied and their elution characteristics were compared to a green fluorescent protein. Using established methods for determining retention characteristics of biomolecules in ion exchange chromatography lead to remarkable results. In contrast to the green fluorescent protein, plasmid DNA consistently elutes at one characteristic salt concentration in linear gradient elution. This salt concentration was the same independent of plasmid size but differed slightly for different resins. The behavior is consistent also at preparative loadings of plasmid DNA. Thus, only a single linear gradient elution experiment is sufficient to design elution in a process scale capture step. At isocratic elution conditions, plasmid DNA elutes only above this characteristic concentration. Even at slightly lower concentrations most plasmids remain tightly bound. We hypothesize, that the desorption is accompanied by a conformational change leading to a reduced number of available negative charges for binding. This explanation is supported by structural analysis before and after elution.
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Affiliation(s)
- Jürgen Beck
- Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Matthias Biechele
- Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Christoph Repik
- Baxalta Innovations GmbH, A Part of Takeda Companies, Orth an der Donau, Austria
| | - Petra Gruber
- Baxalta Innovations GmbH, A Part of Takeda Companies, Orth an der Donau, Austria
| | - Paul G Furtmüller
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Rainer Hahn
- Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Austria
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2
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Celis Bustos YA, Vanesa Rubio V, Camacho Navarro MM. Perspectiva histórica del origen evolutivo de la resistencia a antibióticos. REVISTA COLOMBIANA DE BIOTECNOLOGÍA 2017. [DOI: 10.15446/rev.colomb.biote.v19n2.69501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
La resistencia a antimicrobianos representa un aspecto natural de evolución bacteriana, que puede resultar de mutaciones o por adquisición de genes foráneos. Hay diferentes posturas sobre el origen de ésta resistencia que explican la habilidad de estos microorganismos de adquirir nuevas características. Las teorías de la evolución de Lamarck y Darwin, han dado pie a experimentos diseñados para explorar el origen de la variación bacteriana y surgimiento de nuevas características. Estos estudios muestran que la resistencia está relacionada con mutaciones en genes cromosomales y/o la transferencia de elementos genéticos extracromosomales, que se expresan según la presión antibiótica ejercida. Está revisión recopila los principales experimentos y las conclusiones derivadas para explicar el fenómeno de resistencia a antibióticos.
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Plasmid-Mediated Antibiotic Resistance and Virulence in Gram-negatives: the Klebsiella pneumoniae Paradigm. Microbiol Spectr 2014; 2:1-15. [PMID: 25705573 DOI: 10.1128/microbiolspec.plas-0016-2013] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae. This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections.
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Petrova M, Kurakov A, Shcherbatova N, Mindlin S. Genetic structure and biological properties of the first ancient multiresistance plasmid pKLH80 isolated from a permafrost bacterium. MICROBIOLOGY-SGM 2014; 160:2253-2263. [PMID: 25063046 DOI: 10.1099/mic.0.079335-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A novel multidrug-resistance plasmid, pKLH80, previously isolated from Psychrobacter maritimus MR29-12 found in ancient permafrost, was completely sequenced and analysed. In our previous studies, we focused on the pKLH80 plasmid region containing streptomycin and tetracycline resistance genes, and their mobilization with an upstream-located ISPpy1 insertion sequence (IS) element. Here, we present the complete sequence of pKLH80 and analysis of its backbone genetic structure, including previously unknown features of the plasmid's accessory region, notably a novel variant of the β-lactamase gene blaRTG-6. Plasmid pKLH80 was found to be a circular 14 835 bp molecule that has an overall G+C content of 40.3 mol% and encodes 20 putative ORFs. There are two distinctive functional modules within the plasmid backbone sequence: (i) the replication module consisting of repB and the oriV region; and (ii) the mobilization module consisting of mobA, mobC and oriT. All of the aforementioned genes share sequence identities with corresponding genes of different species of Psychrobacter. The plasmid accessory region contains antibiotic resistance genes and IS elements (ISPsma1 of the IS982 family, and ISPpy1 and ISAba14 of the IS3 family) found in environmental and clinical bacterial strains of different taxa. We revealed that the sequences flanking blaRTG-6 and closely related genes from clinical bacteria are nearly identical. This fact suggests that blaRTG-6 from the environmental strain of Psychrobacter is a progenitor of blaRTG genes of clinical bacteria. We also showed that pKLH80 can replicate in different strains of Acinetobacter and Psychrobacter genera. The roles of IS elements in the horizontal transfer of antibiotic resistance genes are examined and discussed.
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Affiliation(s)
- Mayya Petrova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov sq. 2, Moscow 123182, Russia
| | - Anton Kurakov
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov sq. 2, Moscow 123182, Russia
| | - Natalya Shcherbatova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov sq. 2, Moscow 123182, Russia
| | - Sofia Mindlin
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov sq. 2, Moscow 123182, Russia
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Rakowski SA, Filutowicz M. Plasmid R6K replication control. Plasmid 2013; 69:231-42. [PMID: 23474464 DOI: 10.1016/j.plasmid.2013.02.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 02/14/2013] [Accepted: 02/16/2013] [Indexed: 10/27/2022]
Abstract
The focus of this minireview is the replication control of the 39.9-kb plasmid R6K and its derivatives. Historically, this plasmid was thought to have a narrow host range but more recent findings indicate that its derivatives can replicate in a variety of enteric and non-enteric bacterial species (Wild et al., 2004). In the four-plus decades since it was first described, R6K has proven to be an excellent model for studies of plasmid DNA replication. In part this is because of its similarities to other systems in which replication is activated and regulated by Rep protein and iteron-containing DNA. However its apparent idiosynchracies have also added to its significance (e.g., independent and co-dependent replication origins, and Rep dimers that stably bind iterons). Here, we survey the current state of knowledge regarding R6K replication and place individual regulatory elements into a proposed homeostatic model with implications for the biological significance of R6K and its multiple origins of replication.
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Affiliation(s)
- Sheryl A Rakowski
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
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Bok JW, Keller NP. Fast and easy method for construction of plasmid vectors using modified quick-change mutagenesis. Methods Mol Biol 2012; 944:163-74. [PMID: 23065615 PMCID: PMC3692276 DOI: 10.1007/978-1-62703-122-6_11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Plasmid vector construction is an essential step for molecular microbiology yet often a time-consuming process. Manipulation of the fungal genome to express genes to activate secondary metabolite production often requires creation of plasmid constructs in a reiterative fashion. Here we introduce a modified Quick-change site-directed mutagenesis method that allows for rapid and accurate construction of fungal transformation vectors.
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Nucleotide sequence analysis of small cryptic plasmid pGP2 from Acetobacter estunensis. Biologia (Bratisl) 2011. [DOI: 10.2478/s11756-011-0017-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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Cronin M, Ventura M, Fitzgerald GF, van Sinderen D. Progress in genomics, metabolism and biotechnology of bifidobacteria. Int J Food Microbiol 2011; 149:4-18. [PMID: 21320731 DOI: 10.1016/j.ijfoodmicro.2011.01.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 01/06/2011] [Accepted: 01/10/2011] [Indexed: 12/16/2022]
Abstract
Members of the genus Bifidobacterium were first described over a century ago and were quickly associated with a healthy intestinal tract due to their numerical dominance in breast-fed babies as compared to bottle-fed infants. Health benefits elicited by bifidobacteria to its host, as supported by clinical trials, have led to their wide application as probiotic components of health-promoting foods, especially in fermented dairy products. However, the relative paucity of genetic tools available for bifidobacteria has impeded development of a comprehensive molecular understanding of this genus. In this review we present a summary of current knowledge on bifidobacterial metabolism, classification, physiology and genetics and outline the currently available methods for genetically accessing and manipulating the genus.
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Affiliation(s)
- Michelle Cronin
- Cork Cancer Research Centre, Mercy University Hospital and Leslie C. Quick Jnr. Laboratory, University College Cork, Cork, Ireland
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Norman A, Hansen LH, Sørensen SJ. Conjugative plasmids: vessels of the communal gene pool. Philos Trans R Soc Lond B Biol Sci 2009; 364:2275-89. [PMID: 19571247 DOI: 10.1098/rstb.2009.0037] [Citation(s) in RCA: 314] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Comparative whole-genome analyses have demonstrated that horizontal gene transfer (HGT) provides a significant contribution to prokaryotic genome innovation. The evolution of specific prokaryotes is therefore tightly linked to the environment in which they live and the communal pool of genes available within that environment. Here we use the term supergenome to describe the set of all genes that a prokaryotic 'individual' can draw on within a particular environmental setting. Conjugative plasmids can be considered particularly successful entities within the communal pool, which have enabled HGT over large taxonomic distances. These plasmids are collections of discrete regions of genes that function as 'backbone modules' to undertake different aspects of overall plasmid maintenance and propagation. Conjugative plasmids often carry suites of 'accessory elements' that contribute adaptive traits to the hosts and, potentially, other resident prokaryotes within specific environmental niches. Insight into the evolution of plasmid modules therefore contributes to our knowledge of gene dissemination and evolution within prokaryotic communities. This communal pool provides the prokaryotes with an important mechanistic framework for obtaining adaptability and functional diversity that alleviates the need for large genomes of specialized 'private genes'.
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Affiliation(s)
- Anders Norman
- Department of Biology, Section for Evolution and Microbiology, University of Copenhagen, Copenhagen K, Denmark.
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10
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Abstract
A clear imperative exists to generate radically different antibacterial technologies that will reduce the usage of conventional chemical antibiotics. Here we trace one route into this new frontier of drug discovery, a concept that we call the bacterial conjugation-based technologies (BCBT). One of the objectives of the BCBT is to exploit plasmid biology for combating the rising tide of antibiotic-resistant bacteria. Specifically, the concept utilizes conjugationally delivered plasmids as antimicrobial agents, and it builds on the accumulated work of many scientists dating back to the discoveries of conjugation and plasmids themselves. Each of the individual components that comprise the approach has been demonstrated to be feasible. We discuss the properties of bacterial plasmids to be employed in BCBT.
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Characterization of endogenous plasmids from Lactobacillus salivarius UCC118. Appl Environ Microbiol 2008; 74:3216-28. [PMID: 18390685 DOI: 10.1128/aem.02631-07] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genome of Lactobacillus salivarius UCC118 comprises a 1.83-Mb chromosome, a 242-kb megaplasmid (pMP118), and two smaller plasmids of 20 kb (pSF118-20) and 44 kb (pSF118-44). Annotation and bioinformatic analyses suggest that both of the smaller plasmids replicate by a theta replication mechanism. Furthermore, it appears that they are transmissible, although neither possesses a complete set of conjugation genes. Plasmid pSF118-20 encodes a toxin-antitoxin system composed of pemI and pemK homologs, and this plasmid could be cured when PemI was produced in trans. The minimal replicon of pSF118-20 was determined by deletion analysis. Shuttle vector derivatives of pSF118-20 were generated that included the replication region (pLS203) and the replication region plus mobilization genes (pLS208). The plasmid pLS203 was stably maintained without selection in Lactobacillus plantarum, Lactobacillus fermentum, and the pSF118-20-cured derivative strain of L. salivarius UCC118 (strain LS201). Cloning in pLS203 of genes encoding luciferase and green fluorescent protein, and expression from a constitutive L. salivarius promoter, demonstrated the utility of this vector for the expression of heterologous genes in Lactobacillus. This study thus expands the knowledge base and vector repertoire of probiotic lactobacilli.
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Soler Bistué AJC, Birshan D, Tomaras AP, Dandekar M, Tran T, Newmark J, Bui D, Gupta N, Hernandez K, Sarno R, Zorreguieta A, Actis LA, Tolmasky ME. Klebsiella pneumoniae multiresistance plasmid pMET1: similarity with the Yersinia pestis plasmid pCRY and integrative conjugative elements. PLoS One 2008; 3:e1800. [PMID: 18350140 PMCID: PMC2262945 DOI: 10.1371/journal.pone.0001800] [Citation(s) in RCA: 35] [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: 01/23/2008] [Accepted: 02/15/2008] [Indexed: 11/30/2022] Open
Abstract
Background Dissemination of antimicrobial resistance genes has become an important public health and biodefense threat. Plasmids are important contributors to the rapid acquisition of antibiotic resistance by pathogenic bacteria. Principal Findings The nucleotide sequence of the Klebsiella pneumoniae multiresistance plasmid pMET1 comprises 41,723 bp and includes Tn1331.2, a transposon that carries the blaTEM-1 gene and a perfect duplication of a 3-kbp region including the aac(6′)-Ib, aadA1, and blaOXA-9 genes. The replication region of pMET1 has been identified. Replication is independent of DNA polymerase I, and the replication region is highly related to that of the cryptic Yersinia pestis 91001 plasmid pCRY. The potential partition region has the general organization known as the parFG locus. The self-transmissible pMET1 plasmid includes a type IV secretion system consisting of proteins that make up the mating pair formation complex (Mpf) and the DNA transfer (Dtr) system. The Mpf is highly related to those in the plasmid pCRY, the mobilizable high-pathogenicity island from E. coli ECOR31 (HPIECOR31), which has been proposed to be an integrative conjugative element (ICE) progenitor of high-pathogenicity islands in other Enterobacteriaceae including Yersinia species, and ICEKp1, an ICE found in a K. pneumoniae strain causing primary liver abscess. The Dtr MobB and MobC proteins are highly related to those of pCRY, but the endonuclease is related to that of plasmid pK245 and has no significant homology with the protein of similar function in pCRY. The region upstream of mobB includes the putative oriT and shares 90% identity with the same region in the HPIECOR31. Conclusions The comparative analyses of pMET1 with pCRY, HPIECOR31, and ICEKp1 show a very active rate of genetic exchanges between Enterobacteriaceae including Yersinia species, which represents a high public health and biodefense threat due to transfer of multiple resistance genes to pathogenic Yersinia strains.
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Affiliation(s)
- Alfonso J. C. Soler Bistué
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Daniel Birshan
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Andrew P. Tomaras
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Manisha Dandekar
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Tung Tran
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Jason Newmark
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Duyen Bui
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Nisha Gupta
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Keziah Hernandez
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Renee Sarno
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Angeles Zorreguieta
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
| | - Luis A. Actis
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Marcelo E. Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California, United States of America
- * To whom correspondence should be addressed. E-mail:
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Anand SP, Akhtar P, Tinsley E, Watkins SC, Khan SA. GTP-dependent polymerization of the tubulin-like RepX replication protein encoded by the pXO1 plasmid of Bacillus anthracis. Mol Microbiol 2008; 67:881-90. [PMID: 18179418 DOI: 10.1111/j.1365-2958.2007.06100.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
RepX protein encoded by the pXO1 plasmid of Bacillus anthracis is required for plasmid replication. RepX harbours the tubulin signature motif and contains limited amino acid sequence homology to the bacterial cell division protein FtsZ. Although replication proteins are not known to polymerize, here we show by electron microscopy that RepX undergoes GTP-dependent polymerization into long filaments. RepX filaments assembled in the presence of GTPgammaS were more stable than those assembled in the presence of GTP, suggesting a role for GTP hydrolysis in the depolymerization of the filaments. Light scattering studies showed that RepX underwent rapid polymerization, and substitution of GTP with GTPgammaS stabilized the filaments. RepX exhibited GTPase activity and a mutation in the tubulin signature motif severely impaired its GTPase activity and its polymerization in vitro. Unlike FtsZ homologues, RepX harbours a highly basic carboxyl-terminal region and exhibits GTP-dependent, non-specific DNA binding activity. We speculate that RepX may be involved in both the replication and segregation of the pXO1 plasmid.
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Affiliation(s)
- Syam P Anand
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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14
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Burian J, Stuchlík S, Kay WW. Replication control of a small cryptic plasmid of Escherichia coli. J Mol Biol 1999; 294:49-65. [PMID: 10556028 DOI: 10.1006/jmbi.1999.3266] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of the RepA initiator protein in replication and copy-number control of pKL1, a small cryptic plasmid of Escherichia coli, was elucidated. The identified ori region encompasses a copy-number control element (cop) and an active single-strand initiation signal (ssi), n'-pasH, which were essential for efficient plasmid replication. The cop region also harbors a region of plasmid incompatibility, inc, encompassing a stem-loop structure, the repA promoter, Prep, as well as two distinct RepA binding sites, BD-1 and BD-2. RepA was shown to bind to these sites quite differently, binding primarily as a monomer or dimer to BD-1 to initiate RepA transcription and plasmid replication, and as higher oligomers to BD-2 to autoregulate repA transcription, the balance being reflected in plasmid copy number. An active integration host factor (IHF) binding sequence was located in the cop region and plasmid replication was shown to be dependent on host IHF encoding genes himA and himD. Low concentrations of IHF predisposed the cop region to RepA binding, although when highly expressed in trans RepA effectively displaced bound IHF and it overcame IHF dependency. Incompatibility was shown to be due to the titration of RepA at the cop locus but could be easily overridden by excess RepA. Both RepA binding sites were required to maintain incompatibility and effective pKL1 replication. Neither antisense RNA nor iterons were found to be involved in pKL1 regulation, thus pKL1 is a novel example of autoregulation of DNA replication. When produced in excess from a helper plasmid, RepA induced pKL1 replication to unusually high levels (>2500 copies/cell). In addition, pKL1 replication could be artificially modulated and a wide range of copy numbers maintained.
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Affiliation(s)
- J Burian
- Department of Biochemistry, the Canadian Bacterial Diseases Network, University of Victoria, Petch Building, Victoria, British Columbia, V8W 3P6, Canada
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Juretschko S, Schönhuber W, Kulakauskas S, Ehrlich DS, Schleifer KH, Amann R. In situ detection of Escherichia coli cells containing ColE1-related plasmids by hybridization to regulatory RNA II. Syst Appl Microbiol 1999; 22:1-8. [PMID: 10188273 DOI: 10.1016/s0723-2020(99)80022-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A method is described for the in situ detection of individual whole fixed cells of Escherichia coli containing ColE1-related plasmids. It makes use of fluorescence in situ hybridization (FISH) and the regulatory RNA II as a target molecule for both, Cy3- and HRP-labeled olinucleotide probes. Various methods for signal amplification were compared. Probes targeting the regulatory RNA I did not result in the in situ detection of plasmid-bearing cells.
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Affiliation(s)
- S Juretschko
- Lehrstuhl für Mikrobiologie, Technische Universität München, Germany
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16
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Abstract
The term "plasmid" was introduced 45 years ago (J. Lederberg, 1952, Physiol. Rev. 32, 403-430) as a generic term for any extrachromosomal genetic particle. It was intended to clarify the classification of agents that had been thought of disjunctively as parasites, symbionts, organelles, or genes. For a decade or more it was confused with "episome," although that was carefully crafted (F. Jacob and E. L. Wollman, 1958, C. R. Acad. Sci. 247, 154-156) to mean agents with traffic in and out of chromosomes. Starting about 1970, plasmids became important reagents in molecular genetic research and biotechnology. They also play a cardinal role in the evolution of microbial resistance and of pathogenicity. The usage of the term has then escalated to its current peak of about 3000 published articles per year. The bedrock of genetic mechanism is no longer mitosis and meiosis of chromosomes; it is template-directed DNA assembly. This is often more readily studied and managed with the use of plasmids, which replicate autonomously outside the chromosomes. Some plasmids are also episomes, namely, they interact with the chromosomal genome, and other mobile elements may be transposed from one chromosomal locus to another without replicating autonomously.
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Affiliation(s)
- J Lederberg
- Raymond and Beverly Sackler Foundation Scholar, Rockefeller University, New York, New York 10021-6399, USA
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17
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Tami JA. Major Techniques of Biotechnology. J Pharm Pract 1998. [DOI: 10.1177/089719009801100106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Since the discovery of the structure and function of DNA over 40 years ago, the established knowledge of molecular biology has increased dramatically, and many new tools have been discovered and utilized by scientists to develop new therapeutic agents. Important tools that are used in recombinant DNA technology include restriction endonucleases (cleave DNA), DNA ligase (link DNA molecules together), and cloning vectors (place foreign DNA into an organism such as bacterial or yeast cells in order to mass produce the protein encoded by that foreign DNA). The development of hybridoma technology provided a method to produce virtually unlimited quantities of pure antibody with a single specificity. These immuno-globulins are known as monoclonal antibodies, and have provided both therapeutic and diagnostic agents. Antisense molecules are oligonucleotides which bind to the messenger RNA (mRNA) of a target gene and selectively inhibit the production of specific proteins. Potential applications for these molecules include cancer and viral and inflammatory diseases. The more recent development of the polymerase chain reaction (PCR) has provided a tool that has revolutionized diagnostic testing in diverse areas such as infectious diseases, genetic abnormalities, and cancer.
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Affiliation(s)
- Joseph A. Tami
- Drug Development, Isis Pharmaceuticals, 2292 Faraday Avenue, Carlsbad, CA, 92008
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18
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Dery KJ, Chavideh R, Waters V, Chamorro R, Tolmasky LS, Tolmasky ME. Characterization of the replication and mobilization regions of the multiresistance Klebsiella pneumoniae plasmid pJHCMW1. Plasmid 1997; 38:97-105. [PMID: 9339467 DOI: 10.1006/plas.1997.1303] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A 2.4-kb EcoRI fragment including the replication and origin of transfer regions of the Klebsiella pneumoniae multiresistance plasmid pJHCMW1 has been cloned and sequenced. The isolated replication region was sufficient for stable maintenance of the plasmid and shares homology with RNA-regulated replicons. Homology was highest with the replication region of the plasmid p15A. Incompatibility experiments, however, determined that pJHCMW1 is compatible with pACYC177, a plasmid harboring the p15A replicon. Differences in their RNA I nucleotide sequences may account for their compatibility. A mobilization origin was also found in the 2.4-kb EcoRI pJHCMW1 DNA fragment analyzed. Conjugation experiments showed that although non-self-transmissible, the recombinant clone including the 2.4-kb EcoRI pJHCMW1 fragment could be mobilized in the presence of the helper plasmid pRK2073.
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Affiliation(s)
- K J Dery
- Department of Biological Science, School of Natural Sciences and Mathematics, California State University Fullerton 92834-6850, USA
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19
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KARCHER SUSANJ. RECOMBINANT DNA CLONING. Mol Biol 1995. [DOI: 10.1016/b978-012397720-5.50036-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Bergan RC, Kyle E, Connell Y, Neckers L. Inhibition of protein-tyrosine kinase activity in intact cells by the aptameric action of oligodeoxynucleotides. ANTISENSE RESEARCH AND DEVELOPMENT 1995; 5:33-8. [PMID: 7542047 DOI: 10.1089/ard.1995.5.33] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Direct interaction of oligodeoxynucleotides (ODNs) with proteins represents one of the nonantisense-mediated effects of ODNs. Phosphorothioate-capped ODNs have been shown to inhibit directly the in vitro kinase activity of the chronic myelogenous leukemia-associated protein-tyrosine kinase p210bcr-abl. In this study we have determined the efficacy of this aptameric ODN in a cellular system using the K562 chronic myelogenous leukemia-derived cell line. Significant effects upon cellular phosphotyrosine content, as well as cellular growth in soft agar, are observed. These effects are sequence specific and are not mediated through changes in p210bcr-abl protein levels. Additional ODNs are described that also reduce cellular phosphotyrosine levels and inhibit growth in soft agar but do not inhibit p210bcr-abl kinase activity in vitro.
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Affiliation(s)
- R C Bergan
- Medical Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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