# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 370 | 0 | 1.0000 | A new series of yeast shuttle vectors for the recovery and identification of multiple plasmids from Saccharomyces cerevisiae. The availability of Saccharomyces cerevisiae yeast strains with multiple auxotrophic markers allows the stable introduction and selection of more than one yeast shuttle vector containing marker genes that complement the auxotrophic markers. In certain experimental situations there is a need to recover more than one shuttle vector from yeast. To facilitate the recovery and identification of multiple plasmids from S. cerevisiae, we have constructed a series of plasmids based on the pRS series of yeast shuttle vectors. Bacterial antibiotic resistance genes to chloramphenicol, kanamycin and zeocin have been combined with the yeast centromere sequence (CEN6), the autonomously replicating sequence (ARSH4) and one of the four yeast selectable marker genes (HIS3, TRP1, LEU2 or URA3) from the pRS series of vectors. The 12 plasmids produced differ in antibiotic resistance and yeast marker gene within the backbone of the multipurpose plasmid pBluescript II. The newly constructed vectors show similar mitotic stability to the original pRS vectors. In combination with the ampicillin-resistant pRS series of yeast shuttle vectors, these plasmids now allow the recovery and identification in bacteria of up to four different vectors from S. cerevisiae. | 2007 | 17597491 |
| 384 | 1 | 0.9994 | Broad-host-range mobilizable suicide vectors for promoter trapping in gram-negative bacteria. Here we report the construction of three different vectors for the identification of bacterial genes induced in vitro and/or in vivo. These plasmids contain kanamycin, gentamicin, or tetracycline resistance genes as selectable markers. A promoterless cat and an improved GFP (mut3-gfp) can be used to follow the induction of gene expression by measuring chloramphenicol resistance and fluorescence, respectively. | 2002 | 12449381 |
| 369 | 2 | 0.9994 | A gene fusion system using the aminoglycoside 3'-phosphotransferase gene of the kanamycin-resistance transposon Tn903: use in the yeast Kluyveromyces lactis and Saccharomyces cerevisiae. The aminoglycoside 3'-phosphotransferase type I (APHI)-coding gene of the bacterial transposon Tn903 confers resistance to kanamycin on bacteria and resistance to geneticin (G418) on many eukaryotes. We developed an APHI fusion system that can be used in the study of gene expression in these organisms, particularly in yeasts. The first 19 codons of the KmR (APHI) gene can be deleted, and replaced by other genes in a continuous reading frame, without loss of APH activity. Examples of vector constructions are given which are adapted to the yeast Kluyveromyces lactis transformation system. Their derivatives containing the 2 mu origin of replication can also be used in Saccharomyces cerevisiae. | 1988 | 2853096 |
| 383 | 3 | 0.9993 | Construction of improved vectors and cassettes containing gusA and antibiotic resistance genes for studies of transcriptional activity and bacterial localization. Broad-host-range, conjugative vectors with a constitutively expressed gusA gene combined with different antibiotic resistance (tetracycline, gentamicin, kanamycin) genes have been constructed. These plasmids are designed for tracking Gram-negative bacterial strains without the risk of random mutagenesis. We also constructed a set of cassettes containing a promoterless gusA gene linked with different antibiotic resistance genes for making transcriptional fusions and for cassette mutagenesis. New plasmids and cassettes can be useful tools for studying gene expression, interaction of bacteria with plants and monitoring bacteria in the environment. | 2001 | 11348677 |
| 388 | 4 | 0.9993 | Improved bacterial hosts for regulated expression of genes from lambda pL plasmid vectors. The construction and use of a set of Escherichia coli strains with defective lambda prophages that facilitate expression of genes cloned in lambda pL-plasmid vectors is described. These bacteria allow high and regulated expression of such genes, whereas a kanamycin-resistance marker (KmR) on the prophage allows easy identification and genetic transfer from strain to strain. Optimal conditions for examining gene expression with the pL-vector systems using these strains are discussed. | 1993 | 8406046 |
| 376 | 5 | 0.9993 | Construction of a reporter plasmid for screening in vivo promoter activity in Francisella tularensis. Francisella tularensis is a facultative intracellular bacterium that survives and multiplies inside macrophages. Here we constructed a new promoter probe plasmid denoted pKK214 by introduction of a promoter-less chloramphenicol acetyltransferase (cat) gene into the shuttle vector pKK202. A promoter library was created in F. tularensis strain LVS by cloning random chromosomal DNA fragments into pKK214. Approximately 15% of the recombinant bacteria showed chloramphenicol resistance in vitro. The promoter library was also used to infect macrophages in the presence of chloramphenicol and after two cycles of infection the library contained essentially only chloramphenicol resistance clones which shows that pKK214 can be used to monitor F. tularensis genes that are expressed during infection. | 2001 | 11728719 |
| 386 | 6 | 0.9993 | A mutant neomycin phosphotransferase II gene reduces the resistance of transformants to antibiotic selection pressure. The neo (neomycin-resistance) gene of transposon Tn5 encodes the enzyme neomycin phosphotransferase II (EC 2.7.1.95), which confers resistance to various aminoglycoside antibiotics, including kanamycin and G418. The gene is widely used as a selectable marker in the transformation of organisms as diverse as bacteria, yeast, plants, and animals. We found a mutation that involves a glutamic to aspartic acid conversion at residue 182 in the protein encoded by the chimeric neomycin phosphotransferase II genes of several commonly used transformation vectors. The mutation substantially reduces phosphotransferase activity but does not appear to affect the stability of the neomycin phosphotransferase II mRNA or protein. Plants and bacteria transformed with the mutant gene are less resistant to antibiotics than those transformed with the normal gene. A simple restriction endonuclease digestion distinguishes between the mutant and the normal gene. | 1990 | 2159150 |
| 284 | 7 | 0.9993 | Expression of a transposable antibiotic resistance element in Saccharomyces. Some eukaryotic genes can be expressed in bacteria but there are few examples of the expression of prokaryotic genes in eukaryotes. Antibiotic G418 is a 2-deoxystreptamine antibiotic that is structurally related to gentamicin but has inhibitory activity against a much wider variety of pro- and eukaryotic organisms. In bacteria, resistance to G418 can be determined by several plasmid-encoded modifiying enzymes and, in view of the broad spectrum of activity of G418, we considered that this antibiotic might be useful as a selective agent for the introduction of these antibiotic resistance genes into a eukaryotic organism such as Saccharomyces cerevisiae. Additional impetus for these experiments came from the knowledge that certain of the G418-resistance determinants in bacteria are carried on transposable elements; a study of the properties of these elements in eukaryotes would be intriguing. | 1980 | 6253817 |
| 352 | 8 | 0.9993 | Transposon vectors containing non-antibiotic resistance selection markers for cloning and stable chromosomal insertion of foreign genes in gram-negative bacteria. A simple procedure for cloning and stable insertion of foreign genes into the chromosomes of gram-negative eubacteria was developed by combining in two sets of plasmids (i) the transposition features of Tn10 and Tn5; (ii) the resistances to the herbicide bialaphos, to mercuric salts and organomercurial compounds, and to arsenite, and (iii) the suicide delivery properties of the R6K-based plasmid pGP704. The resulting constructions contained unique NotI or SfiI sites internal to either the Tn10 or the Tn5 inverted repeats. These sites were readily used for cloning DNA fragments with the help of two additional specialized cloning plasmids, pUC18Not and pUC18Sfi. The newly derived constructions could be maintained only in donor host strains that produce the R6K-specified pi protein, which is an essential replication protein for R6K and plasmids derived therefrom. Donor plasmids containing hybrid transposons were transformed into a specialized lambda pir lysogenic Escherichia coli strain with a chromosomally integrated RP4 that provided broad-host-range conjugal transfer functions. Delivery of the donor plasmids into selected host bacteria was accomplished through mating with the target strain. Transposition of the hybrid transposon from the delivered suicide plasmid to a replicon in the target cell was mediated by the cognate transposase encoded on the plasmid at a site external to the transposon. Since the transposase function was not maintained in target cells, such cells were not immune to further transposition rounds. Multiple insertions in the same strain are therefore only limited by the availability of distinct selection markers. The utility of the system was demonstrated with a kanamycin resistance gene as a model foreign insert into Pseudomonas putida and a melanin gene from Streptomyces antibioticus into Klebsiella pneumoniae. Because of the modular nature of the functional parts of the cloning vectors, they can be easily modified and further selection markers can be incorporated. The cloning system described here will be particularly useful for the construction of hybrid bacteria that stably maintain inserted genes, perhaps in competitive situations (e.g., in open systems and natural environments), and that do not carry antibiotic resistance markers characteristic of most available cloning vectors (as is currently required of live bacterial vaccines). | 1990 | 2172216 |
| 351 | 9 | 0.9993 | Rapid and efficient cloning of proviral flanking fragments by kanamycin resistance gene complementation. We have developed a technique for the rapid cloning of unknown flanking regions of transgenic DNA. We complemented a truncated kanamycin resistance gene of a bacterial plasmid with a neomycin resistance gene fragment from a gene transfer vector. Optimized transformation conditions allowed us to directly select for kanamycin-resistant bacteria. We cloned numerous proviral flanking fragments from growth factor-independent cell mutants that were obtained after infection with a replication incompetent retroviral vector and identified integrations into the cyclin D2 and several unknown genomic sequences. We anticipate that our method could be adapted to various vector systems that are used to tag and identify genes and to map genomes. | 1999 | 9863001 |
| 379 | 10 | 0.9993 | Broad host range DNA cloning system for gram-negative bacteria: construction of a gene bank of Rhizobium meliloti. A broad host range cloning vehicle that can be mobilized at high frequency into Gram-negative bacteria has been constructed from the naturally occurring antibiotic resistance plasmid RK2. The vehicle is 20 kilobase pairs in size, encodes tetracycline resistance, and contains two single restriction enzyme sites suitable for cloning. Mobilization is effected by a helper plasmid consisting of the RK2 transfer genes linked to a ColE1 replicon. By use of this plasmid vehicle, a gene bank of the DNA from a wild-type strain of Rhizobium meliloti has been constructed and established in Escherichia coli. One of the hybrid plasmids in the bank contains a DNA insert of approximately 26 kilobase pairs which has homology to the nitrogenase structural gene region of Klebsiella pneumoniae. | 1980 | 7012838 |
| 381 | 11 | 0.9992 | A panel of Tn7-based vectors for insertion of the gfp marker gene or for delivery of cloned DNA into Gram-negative bacteria at a neutral chromosomal site. The use of Tn7-based systems for site-specific insertion of DNA into the chromosome of Gram-negative bacteria has been limited due to the lack of appropriate vectors. We therefore developed a flexible panel of Tn7 delivery vectors. In one group of vectors, the miniTn7 element, which is inserted into the chromosome, contains a multiple cloning site (MCS) and the kanamycin, streptomycin or gentamicin resistance markers. Another group of vectors intended for tagging with green fluorescent protein (GFP) carries the gfpmut3* gene controlled by the modified lac promoter PA1/04/03, several transcriptional terminators, and various resistance markers. These vectors insert Tn7 into a specific, neutral intergenic region immediately downstream of the gene encoding glucosamine-6-phosphate synthetase (GlmS) in the tested fluorescent Pseudomonas strains. The gfp-tagging vector containing a gentamicin-resistance marker is useful for tagging strains carrying a Tn5 transposon. Tn5 transposons often carry kanamycin-resistance-encoding genes and are frequently used to generate bacterial mutants and to deliver reporter constructions in gene expression studies. To demonstrate the utility of a dual marker/reporter system, the Tn7-gfp marker system was combined with a Tn5-delivered luxAB reporter system in Pseudomonas fluorescens. The system allowed detection of gfp-tagged cells in the barley rhizosphere, while expression of the Tn5-tagged locus could be determined by measuring bioluminescence. | 2001 | 11348676 |
| 255 | 12 | 0.9992 | Versatile nourseothricin and streptomycin/spectinomycin resistance gene cassettes and their use in chromosome integration vectors. An obstacle for the development of genetic systems for many bacteria is the limited number of antibiotic selection markers, especially for bacteria that are intrinsically antibiotic resistant or where utilization of such markers is strictly regulated. Here we describe the development of versatile cassettes containing nourseothricin, streptomycin/spectinomycin, and spectinomycin selection markers. The antibiotic resistance genes contained on these cassettes are flanked by loxP sites with allow their in vivo excision from the chromosome of target bacteria using Cre recombinase. The respective selection marker cassettes were used to derive mini-Tn7 elements that can be used for single-copy insertion of genes into bacterial chromosomes. The utility of the selection markers was tested by insertion of the resulting mini-Tn7 elements into the genomes of Burkholderia thailandensis and B. pseudomallei efflux pump mutants susceptible to aminoglycosides, aminocyclitols, and streptothricins, followed by Cre-mediated antibiotic resistance marker excision. The versatile nourseothricin, streptomycin/spectinomycin and spectinomycin resistance loxP cassette vectors described here extend the repertoire of antibiotic selection markers for genetic manipulation of diverse bacteria that are susceptible to aminoglycosides and aminocyclitols. | 2016 | 27457407 |
| 377 | 13 | 0.9992 | Construction of improved plasmid vectors for promoter characterization in Pseudomonas aeruginosa and other gram-negative bacteria. We report the construction of two broad host range promoter-probe plasmid vectors for rapid analysis of promoters in Gram-negative bacteria. The new vectors, pME4507 and pME4510, carry carbenicillin and gentamycin resistance genes, respectively, and are small sized (4 kb) with a flexible multiple cloning site to facilitate directional cloning of putative promoter elements. The vectors allow rapid plate-based screening for promoter activities, using beta-galactosidase as the reporter enzyme. In the absence of an inserted promoter fragment, they display very low background activity, making them a useful tool for analysis of low expression level promoters. | 1998 | 9851050 |
| 387 | 14 | 0.9992 | Expression of tetracycline resistance in pBR322 derivatives reduces the reproductive fitness of plasmid-containing Escherichia coli. Plasmid pBR322 and its numerous derivatives are used extensively for research and in biotechnology. The tetracycline-resistance (TcR) genes in these plasmids are expressed constitutively and cells carrying these plasmids are resistant to tetracycline. We have shown that expression of the TcR gene has an adverse effect on the reproductive fitness of plasmid-containing bacteria in both glucose-limited batch and chemostat cultures. If the TcR genes are inactivated at any one of three different restriction sites, mixed cultures of plasmid-free and plasmid-containing bacteria grow at the same rate. | 1985 | 3005111 |
| 260 | 15 | 0.9992 | Improved antibiotic resistance gene cassette for marker exchange mutagenesis in Ralstonia solanacearum and Burkholderia species. Marker exchange mutagenesis is a fundamental approach to understanding gene function at a molecular level in bacteria. New plasmids carrying a kanamycin resistance gene or a trimethoprim resistance gene were constructed to provide antibiotic resistance cassettes for marker exchange mutagenesis in Ralstonia solanacearum and many antibiotic-resistant Burkholderia spp. Insertion sequences present in the flanking sequences of the antibiotic resistance cassette were removed to prevent aberrant gene replacement and polar mutation during mutagenesis in wild-type bacteria. Plasmids provided in this study would be convenient for use in gene cassettes for gene replacement in other Gram-negative bacteria. | 2011 | 21538255 |
| 353 | 16 | 0.9992 | Genome modifications and cloning using a conjugally transferable recombineering system. The genetic modification of primary bacterial disease isolates is challenging due to the lack of highly efficient genetic tools. Herein we describe the development of a modified PCR-based, λ Red-mediated recombineering system for efficient deletion of genes in Gram-negative bacteria. A series of conjugally transferrable plasmids were constructed by cloning an oriT sequence and different antibiotic resistance genes into recombinogenic plasmid pKD46. Using this system we deleted ten different genes from the genomes of Edwardsiella ictaluri and Aeromonas hydrophila. A temperature sensitive and conjugally transferable flp recombinase plasmid was developed to generate markerless gene deletion mutants. We also developed an efficient cloning system to capture larger bacterial genetic elements and clone them into a conjugally transferrable plasmid for facile transferring to Gram-negative bacteria. This system should be applicable in diverse Gram-negative bacteria to modify and complement genomic elements in bacteria that cannot be manipulated using available genetic tools. | 2015 | 28352570 |
| 357 | 17 | 0.9992 | New antibiotic resistance cassettes suitable for genetic studies in Borrelia burgdorferi. In this report we describe two distinct approaches to develop new antibiotic resistance cassettes that allow for efficient selection of Borrelia burgdorferi transformants. The first approach utilizes fusions of borrelial flagellar promoters to antibiotic resistance markers from other bacteria. The AACC1 gene, which encodes a gentamicin acetyltransferase, conferred a high level of gentamicin resistance in B. Burfdorferi when expressed from these promoters. No cross-resistance occurred between this cassette and the kanamycin resistance cassette, which was previously developed in an analogous fashion. A second and different approach was taken to develop an efficient selectable marker that confers resistance to the antibiotic coumermycin A1. A synthetic gene was designed from the GYRB301 allele of the coumermycin-resistant B. Burgdorferi strain B31-NGR by altering the coding sequence at the wobble position. The resulting gene, GYRB(SYN), encodes a protein identical to the product of GYRB301, but the genes share only 66% nucleotide identity. The nucleotide sequence of GYRB(SYN)is sufficiently divergent from the endogenous B. Burgdorferi GYRB gene to prevent recombination between them. The cassettes described in this paper improve our repertoire of genetic tools in B. Burgdorferi. These studies also provide insight into parameters governing recombination and gene expression in B. Burgdorferi. | 2003 | 14593251 |
| 285 | 18 | 0.9992 | Streptothricin resistance as a novel selectable marker for transgenic plant cells.  Streptothricins are known as antimicrobial agents produced by Streptomyces spp. Bacterial resistance to streptothricin is mediated by specific enzymes exhibiting an acetyltransferase activity which renders the drug non-toxic for bacteria. The nucleotide sequence of several streptothricin resistance genes from bacteria have been described. Certain cells of eukaryotic parasites (such as Ustilago maydis or Leishmania spp.) are sensitive to streptothricin and the introduction of the bacterial resistance gene sat2 renders them resistant. We show that numerous species of plants are sensitive to low concentrations of streptothricin. Moreover, introduction of the bacterial resistance gene sat3 under the control of the 35S cauliflower mosaic virus promoter protects these cells from the toxic action of streptothricin. Therefore, sat3-mediated streptothricin resistance appears to be a promising selective marker for genetic manipulation of plant cells. | 2000 | 30754912 |
| 272 | 19 | 0.9992 | Chromatic Bacteria - A Broad Host-Range Plasmid and Chromosomal Insertion Toolbox for Fluorescent Protein Expression in Bacteria. Differential fluorescent labeling of bacteria has become instrumental for many aspects of microbiological research, such as the study of biofilm formation, bacterial individuality, evolution, and bacterial behavior in complex environments. We designed a variety of plasmids, each bearing one of eight unique, constitutively expressed fluorescent protein genes in conjunction with one of four different antibiotic resistance combinations. The fluorophores mTagBFP2, mTurquoise2, sGFP2, mClover3, sYFP2, mOrange2, mScarlet-I, and mCardinal, encoding for blue, cyan, green, green-yellow, yellow, orange, red, and far-red fluorescent proteins, respectively, were combined with selectable markers conferring tetracycline, gentamicin, kanamycin, and/or chloramphenicol resistance. These constructs were cloned into three different plasmid backbones: a broad host-range plasmid, a Tn5 transposon delivery plasmid, and a Tn7 transposon delivery plasmid. The utility of the plasmids and transposons was tested in bacteria from the phyla Actinobacteria, Proteobacteria, and Bacteroidetes. We were able to tag representatives from the phylum Proteobacteria at least via our Tn5 transposon delivery system. The present study enables labeling bacteria with a set of plasmids available to the community. One potential application of fluorescently-tagged bacterial species is the study of bacteria-bacteria, bacteria-host, and bacteria-environment interactions. | 2018 | 30631309 |