Details
- Autor(en) / Beteiligte
- Titel
- An O island 172 encoded RNA helicase regulates the motility of Escherichia coli O157:H7
- Ist Teil von
- PloS one, 2013-06, Vol.8 (6), p.e64211
- Ort / Verlag
- United States: Public Library of Science
- Erscheinungsjahr
- 2013
- Link zum Volltext
- Quelle
- MEDLINE
- Beschreibungen/Notizen
- Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 is a major cause of zoonotic food- and water-borne intestinal infections worldwide with clinical consequences ranging from mild diarrhoea to hemolytic uraemic syndrome. The genome of EHEC O157:H7 contains many regions of unique DNA that are referred to as O islands including the Shiga toxin prophages and pathogenicity islands encoding key virulence factors. However many of these O islands are of unknown function. In this study, genetic analysis was conducted on OI-172 which is a 44,434 bp genomic island with 27 open reading frames. Comparative genome analysis showed that O1-72 is a composite island with progressive gain of genes since O157:H7 evolved from its ancestral O55:H7. A partial OI-172 island was also found in 2 unrelated E. coli strains and 2 Salmonella strains. OI-172 encodes several putative helicases, one of which (Z5898) is a putative DEAH box RNA helicase. To investigate the function of Z5898, a deletion mutant (EDL933ΔZ5898) was constructed in the O157:H7 strain EDL933. Comparative proteomic analysis of the mutant with the wild-type EDL933 found that flagellin was down-regulated in the Z5898 mutant. Motility assay showed that EDL933ΔZ5898 migrated slower than the wild-type EDL933 and electron microscopy found no surface flagella. Quantitative reverse transcription PCR revealed that the fliC expression of EDL933ΔZ5898 was significantly lower while the expression of its upstream regulator gene, fliA, was not affected. Using a fliA and a fliC promoter - green fluorescent protein fusion contruct, Z5898 was found to affect only the fliC promoter activity. Therefore, Z5898 regulates the flagella based motility by exerting its effect on fliC. We conclude that OI-172 is a motility associated O island and hereby name it the MAO island.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 1932-6203eISSN: 1932-6203DOI: 10.1371/journal.pone.0064211Titel-ID: cdi_plos_journals_1367545852
- Format
- –
- Schlagworte
- Amine oxidase (flavin-containing), Amino Acid Motifs, Amino Acid Sequence, Biological evolution, Biology, Collaboration, Conserved Sequence, Deletion mutant, Deoxyribonucleic acid, Diarrhea, Disease control, Disease prevention, DNA, DNA helicase, E coli, Electron microscopy, Escherichia coli, Escherichia coli O157 - genetics, Escherichia coli O157 - metabolism, Escherichia coli Proteins - chemistry, Escherichia coli Proteins - genetics, Escherichia coli Proteins - metabolism, Flagella, Flagellin, Flagellin - genetics, Flagellin - metabolism, Fluorescence, Fusion protein, Gastrointestinal diseases, Gene expression, Gene Expression Regulation, Bacterial, Gene Order, Genes, Genetic analysis, Genomes, Genomic Islands, Genomics, Green fluorescent protein, Health aspects, Infectious diseases, Intestine, Medical diagnosis, Medical laboratories, Motility, Open reading frames, Pathogenesis, Pathogenicity, Pathogenicity islands, Pathogens, Prophages, Proteomics, Reverse transcription, Ribonucleic acid, RNA, RNA helicase, RNA Helicases - chemistry, RNA Helicases - genetics, RNA Helicases - metabolism, Salmonella, Sequence Deletion, Shiga toxin, Transcription, Genetic, Virulence, Virulence factors