Positive regulation of Clostridium difficile toxins
| Autor: | T. D. Wilkins, Lisa Barroso, J S Moncrief |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Bacterial Toxins
Molecular Sequence Data Immunology Clostridium difficile toxin A Clostridium difficile toxin B Biology medicine.disease_cause Microbiology Enterotoxins Plasmid Bacterial Proteins medicine Amino Acid Sequence Promoter Regions Genetic Escherichia coli Peptide sequence Reporter gene Clostridioides difficile Promoter Gene Expression Regulation Bacterial Molecular biology Open reading frame Infectious Diseases Parasitology Research Article |
| Zdroj: | Infection and Immunity. 65:1105-1108 |
| ISSN: | 1098-5522 0019-9567 |
| DOI: | 10.1128/iai.65.3.1105-1108.1997 |
| Popis: | The toxigenic element of Clostridium difficile VPI 10463 contains a small open reading frame (ORF) immediately upstream of the toxin B gene (G. A. Hammond and J. L. Johnson, Microb. Pathog. 19:203-213, 1995). The deduced amino acid sequence of the ORF, which we have designated txeR, encodes a 22-kDa protein which contains a helix-turn-helix motif with sequence identity to DNA binding regulatory proteins. We used a DNA fragment containing the C. difficile toxin A repeating units (ARU) as a reporter gene to determine if txeR regulates expression from the toxin A and toxin B promoters in Escherichia coli. To test the affect of txeR on expression, we fused the ARU gene fragment in frame with the toxin promoters. The fusions expressed a 104-kDa protein that contained the epitopes for monoclonal antibody PCG-4, which we used to measure levels of recombinant ARU by enzyme-linked immunosorbent assay. When txeR was expressed in trans with the toxin B promoter-ARU fusion contained on separate low-copy-number plasmid, expression of ARU increased over 800-fold. Furthermore, when we tested the toxin A promoter fused to ARU, expression increased over 500-fold with txeR supplied in trans. Our results suggest that TxeR is a positive regulator that activates expression of the C. difficile toxins. |
| Databáze: | OpenAIRE |
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