The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform
C. Neal Stewart - One of the best experts on this subject based on the ideXlab platform.
-
An Arabidopsis thaliana ABC transporter that confers Kanamycin Resistance in transgenic plants does not endow Resistance to Escherichia coli
Microbial biotechnology, 2007Co-Authors: Kellie P. Burris, Ayalew Mentewab, Steven Ripp, C. Neal StewartAbstract:Concerns have been raised about potential horizontal gene transfer (HGT) of antibiotic Resistance markers (ARMs) from transgenic plants to bacteria of medical and environmental importance. All ARMs used in transgenic plants have been bacterial in origin, but it has been recently shown that an Arabidopsis thaliana ABC transporter, Atwbc19, confers Kanamycin Resistance when overexpressed in transgenic plants. Atwbc19 was evaluated for its ability to transfer Kanamycin Resistance to Escherichia coli, a Kanamycin‐sensitive model bacterium, under simulated HGT, staged by subcloning Atwbc19 under the control of a bacterial promoter, genetically transforming to Kanamycin‐sensitive bacteria, and assessing if Resistance was conferred as compared with bacteria harbouring nptII, the standard Kanamycin Resistance gene used to produce transgenic plants. NptII provided much greater Resistance than Atwbc19 and was significantly different from the no‐plasmid control at low concentrations. Atwbc19 was not significantly different from the no‐plasmid control at higher concentrations. Even though HGT risks are considered low with nptII, Atwbc19 should have even lower risks, as its encoded protein is possibly mistargeted in bacteria.
-
Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
Nature biotechnology, 2005Co-Authors: Ayalew Mentewab, C. Neal StewartAbstract:Selectable markers of bacterial origin such as the neomycin phosphotransferase type II gene, which can confer Kanamycin Resistance to transgenic plants, represent an invaluable tool for plant engineering. However, since all currently used antibiotic-Resistance genes are of bacterial origin, there have been concerns about horizontal gene transfer from transgenic plants back to bacteria, which may result in antibiotic Resistance. Here we characterize a plant gene, Atwbc19, the gene that encodes an Arabidopsis thaliana ATP binding cassette (ABC) transporter and confers antibiotic Resistance to transgenic plants. The mechanism of Resistance is novel, and the levels of Resistance achieved are comparable to those attained through expression of bacterial antibiotic-Resistance genes in transgenic tobacco using the CaMV 35S promoter. Because ABC transporters are endogenous to plants, the use of Atwbc19 as a selectable marker in transgenic plants may provide a practical alternative to current bacterial marker genes in terms of the risk for horizontal transfer of Resistance genes.
-
Corrigendum: Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
Nature Biotechnology, 2005Co-Authors: Ayalew Mentewab, C. Neal StewartAbstract:Corrigendum: Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
Ayalew Mentewab - One of the best experts on this subject based on the ideXlab platform.
-
An Arabidopsis thaliana ABC transporter that confers Kanamycin Resistance in transgenic plants does not endow Resistance to Escherichia coli
Microbial biotechnology, 2007Co-Authors: Kellie P. Burris, Ayalew Mentewab, Steven Ripp, C. Neal StewartAbstract:Concerns have been raised about potential horizontal gene transfer (HGT) of antibiotic Resistance markers (ARMs) from transgenic plants to bacteria of medical and environmental importance. All ARMs used in transgenic plants have been bacterial in origin, but it has been recently shown that an Arabidopsis thaliana ABC transporter, Atwbc19, confers Kanamycin Resistance when overexpressed in transgenic plants. Atwbc19 was evaluated for its ability to transfer Kanamycin Resistance to Escherichia coli, a Kanamycin‐sensitive model bacterium, under simulated HGT, staged by subcloning Atwbc19 under the control of a bacterial promoter, genetically transforming to Kanamycin‐sensitive bacteria, and assessing if Resistance was conferred as compared with bacteria harbouring nptII, the standard Kanamycin Resistance gene used to produce transgenic plants. NptII provided much greater Resistance than Atwbc19 and was significantly different from the no‐plasmid control at low concentrations. Atwbc19 was not significantly different from the no‐plasmid control at higher concentrations. Even though HGT risks are considered low with nptII, Atwbc19 should have even lower risks, as its encoded protein is possibly mistargeted in bacteria.
-
overexpression of an arabidopsis thaliana abc transporter confers Kanamycin Resistance to transgenic plants
Nature Biotechnology, 2005Co-Authors: Ayalew Mentewab, Neal C StewartAbstract:Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
-
Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
Nature biotechnology, 2005Co-Authors: Ayalew Mentewab, C. Neal StewartAbstract:Selectable markers of bacterial origin such as the neomycin phosphotransferase type II gene, which can confer Kanamycin Resistance to transgenic plants, represent an invaluable tool for plant engineering. However, since all currently used antibiotic-Resistance genes are of bacterial origin, there have been concerns about horizontal gene transfer from transgenic plants back to bacteria, which may result in antibiotic Resistance. Here we characterize a plant gene, Atwbc19, the gene that encodes an Arabidopsis thaliana ATP binding cassette (ABC) transporter and confers antibiotic Resistance to transgenic plants. The mechanism of Resistance is novel, and the levels of Resistance achieved are comparable to those attained through expression of bacterial antibiotic-Resistance genes in transgenic tobacco using the CaMV 35S promoter. Because ABC transporters are endogenous to plants, the use of Atwbc19 as a selectable marker in transgenic plants may provide a practical alternative to current bacterial marker genes in terms of the risk for horizontal transfer of Resistance genes.
-
Corrigendum: Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
Nature Biotechnology, 2005Co-Authors: Ayalew Mentewab, C. Neal StewartAbstract:Corrigendum: Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
Hiroyuki Kagamiyama - One of the best experts on this subject based on the ideXlab platform.
-
directed evolution of thermostable Kanamycin Resistance gene a convenient selection marker for thermus thermophilus
Journal of Biochemistry, 1999Co-Authors: Jun Hoseki, Yoshinori Koyama, Takato Yano, Seiki Kuramitsu, Hiroyuki KagamiyamaAbstract:The whole-genome sequencing of an extreme thermophile, Thermus thermophilus, is now in progress. Like other genome projects, major concern is shifting from the sequence itself to post-sequencing research such as functional or structural genomics. Under such circumstances, the demand for convenient genetic-engineering tools is increasing. In this study we have increased the thermostability of a Kanamycin-Resistance gene product using strategies based on directed evolution in T. thermophilus to the upper limit of its growth temperature. The most thermostable mutant has 19 amino-acid substitutions, whereby the thermostability is increased by 20"C, but the enzymatic activity is not significantly changed. Most of the mutated residues are located on the surface of the protein molecule, and, interestingly, five of the 19 substitutions are those to proline residues. The evolved Kanamycin-Resistance gene products could be used as selection markers at the optimum growth temperature of T. thermophilus. The development of such a convenient genetic-engineering tool would facilitate post-sequencing research on T. thermophilus.
-
directed evolution of thermostable Kanamycin Resistance gene a convenient selection marker for thermus thermophilus
Journal of Biochemistry, 1999Co-Authors: Jun Hoseki, Yoshinori Koyama, Takato Yano, Seiki Kuramitsu, Hiroyuki KagamiyamaAbstract:The whole-genome sequencing of an extreme thermophile, Thermus thermophilus, is now in progress. Like other genome projects, major concern is shifting from the sequence itself to post-sequencing research such as functional or structural genomics. Under such circumstances, the demand for convenient genetic-engineering tools is increasing. In this study we have increased the thermostability of a Kanamycin-Resistance gene product using strategies based on directed evolution in T. thermophilus to the upper limit of its growth temperature. The most thermostable mutant has 19 amino-acid substitutions, whereby the thermostability is increased by 20 degrees C, but the enzymatic activity is not significantly changed. Most of the mutated residues are located on the surface of the protein molecule, and, interestingly, five of the 19 substitutions are those to proline residues. The evolved Kanamycin-Resistance gene products could be used as selection markers at the optimum growth temperature of T. thermophilus. The development of such a convenient genetic-engineering tool would facilitate post-sequencing research on T. thermophilus.
Neal C Stewart - One of the best experts on this subject based on the ideXlab platform.
-
overexpression of an arabidopsis thaliana abc transporter confers Kanamycin Resistance to transgenic plants
Nature Biotechnology, 2005Co-Authors: Ayalew Mentewab, Neal C StewartAbstract:Overexpression of an Arabidopsis thaliana ABC transporter confers Kanamycin Resistance to transgenic plants
Jun Hoseki - One of the best experts on this subject based on the ideXlab platform.
-
directed evolution of thermostable Kanamycin Resistance gene a convenient selection marker for thermus thermophilus
Journal of Biochemistry, 1999Co-Authors: Jun Hoseki, Yoshinori Koyama, Takato Yano, Seiki Kuramitsu, Hiroyuki KagamiyamaAbstract:The whole-genome sequencing of an extreme thermophile, Thermus thermophilus, is now in progress. Like other genome projects, major concern is shifting from the sequence itself to post-sequencing research such as functional or structural genomics. Under such circumstances, the demand for convenient genetic-engineering tools is increasing. In this study we have increased the thermostability of a Kanamycin-Resistance gene product using strategies based on directed evolution in T. thermophilus to the upper limit of its growth temperature. The most thermostable mutant has 19 amino-acid substitutions, whereby the thermostability is increased by 20"C, but the enzymatic activity is not significantly changed. Most of the mutated residues are located on the surface of the protein molecule, and, interestingly, five of the 19 substitutions are those to proline residues. The evolved Kanamycin-Resistance gene products could be used as selection markers at the optimum growth temperature of T. thermophilus. The development of such a convenient genetic-engineering tool would facilitate post-sequencing research on T. thermophilus.
-
directed evolution of thermostable Kanamycin Resistance gene a convenient selection marker for thermus thermophilus
Journal of Biochemistry, 1999Co-Authors: Jun Hoseki, Yoshinori Koyama, Takato Yano, Seiki Kuramitsu, Hiroyuki KagamiyamaAbstract:The whole-genome sequencing of an extreme thermophile, Thermus thermophilus, is now in progress. Like other genome projects, major concern is shifting from the sequence itself to post-sequencing research such as functional or structural genomics. Under such circumstances, the demand for convenient genetic-engineering tools is increasing. In this study we have increased the thermostability of a Kanamycin-Resistance gene product using strategies based on directed evolution in T. thermophilus to the upper limit of its growth temperature. The most thermostable mutant has 19 amino-acid substitutions, whereby the thermostability is increased by 20 degrees C, but the enzymatic activity is not significantly changed. Most of the mutated residues are located on the surface of the protein molecule, and, interestingly, five of the 19 substitutions are those to proline residues. The evolved Kanamycin-Resistance gene products could be used as selection markers at the optimum growth temperature of T. thermophilus. The development of such a convenient genetic-engineering tool would facilitate post-sequencing research on T. thermophilus.
