Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i>
Shiga-toxin producing <i>Escherichia coli</i> (STEC) causes human illness ranging from mild diarrhea to death. The bacteriophage encoded <i>stx</i> genes are located in the late transcription region, downstream of the antiterminator Q. The transcription of the <i>stx<...
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MDPI AG
2018-10-01
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| Series: | Viruses |
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| Online Access: | https://www.mdpi.com/1999-4915/10/11/595 |
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| author | Ling Xiao Zhang David J. Simpson Lynn M. McMullen Michael G. Gänzle |
| author_facet | Ling Xiao Zhang David J. Simpson Lynn M. McMullen Michael G. Gänzle |
| author_sort | Ling Xiao Zhang |
| collection | DOAJ |
| description | Shiga-toxin producing <i>Escherichia coli</i> (STEC) causes human illness ranging from mild diarrhea to death. The bacteriophage encoded <i>stx</i> genes are located in the late transcription region, downstream of the antiterminator Q. The transcription of the <i>stx</i> genes is directly under the control of the late promoter <i>p</i>R’, thus the sequence diversity of the region between <i>Q</i> and <i>stx</i>, here termed the pR’ region, may affect Stx toxin production. Here, we compared the gene structure of the <i>p</i>R’ region and the <i>stx</i> subtypes of nineteen STECs. The sequence alignment and phylogenetic analysis suggested that the <i>p</i>R’ region tends to be more heterogeneous than the promoter itself, even if the prophages harbor the same <i>stx</i> subtype. Furthermore, we established and validated transcriptional fusions of the <i>p</i>R’ region to the DsRed reporter gene using mitomycin C (MMC) induction. Finally, these constructs were transformed into native and non-native strains and examined with flow cytometry. The results showed that induction levels changed when <i>p</i>R’ regions were placed under different regulatory systems. Moreover, not every <i>stx</i> gene could be induced in its native host bacteria. In addition to the functional genes, the diversity of the <i>p</i>R’ region plays an important role in determining the level of toxin induction. |
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| institution | Directory Open Access Journal |
| issn | 1999-4915 |
| language | English |
| last_indexed | 2024-12-12T14:41:12Z |
| publishDate | 2018-10-01 |
| publisher | MDPI AG |
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| series | Viruses |
| spelling | doaj.art-a9be4b352ee74a82b932d86ec5303ec42022-12-22T00:21:13ZengMDPI AGViruses1999-49152018-10-01101159510.3390/v10110595v10110595Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i>Ling Xiao Zhang0David J. Simpson1Lynn M. McMullen2Michael G. Gänzle3Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, CanadaDepartment of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, CanadaDepartment of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, CanadaDepartment of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, CanadaShiga-toxin producing <i>Escherichia coli</i> (STEC) causes human illness ranging from mild diarrhea to death. The bacteriophage encoded <i>stx</i> genes are located in the late transcription region, downstream of the antiterminator Q. The transcription of the <i>stx</i> genes is directly under the control of the late promoter <i>p</i>R’, thus the sequence diversity of the region between <i>Q</i> and <i>stx</i>, here termed the pR’ region, may affect Stx toxin production. Here, we compared the gene structure of the <i>p</i>R’ region and the <i>stx</i> subtypes of nineteen STECs. The sequence alignment and phylogenetic analysis suggested that the <i>p</i>R’ region tends to be more heterogeneous than the promoter itself, even if the prophages harbor the same <i>stx</i> subtype. Furthermore, we established and validated transcriptional fusions of the <i>p</i>R’ region to the DsRed reporter gene using mitomycin C (MMC) induction. Finally, these constructs were transformed into native and non-native strains and examined with flow cytometry. The results showed that induction levels changed when <i>p</i>R’ regions were placed under different regulatory systems. Moreover, not every <i>stx</i> gene could be induced in its native host bacteria. In addition to the functional genes, the diversity of the <i>p</i>R’ region plays an important role in determining the level of toxin induction.https://www.mdpi.com/1999-4915/10/11/595Shiga toxin prophagegenomic characterizationflow cytometrymicroscopephage induction efficiencysequence diversity |
| spellingShingle | Ling Xiao Zhang David J. Simpson Lynn M. McMullen Michael G. Gänzle Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i> Viruses Shiga toxin prophage genomic characterization flow cytometry microscope phage induction efficiency sequence diversity |
| title | Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i> |
| title_full | Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i> |
| title_fullStr | Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i> |
| title_full_unstemmed | Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i> |
| title_short | Comparative Genomics and Characterization of the Late Promoter <i>p</i>R’ from Shiga Toxin Prophages in <i>Escherichia coli</i> |
| title_sort | comparative genomics and characterization of the late promoter i p i r from shiga toxin prophages in i escherichia coli i |
| topic | Shiga toxin prophage genomic characterization flow cytometry microscope phage induction efficiency sequence diversity |
| url | https://www.mdpi.com/1999-4915/10/11/595 |
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