Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant

In gram-negative bacteria, high-affinity iron uptake requires the TonB/ExbB/ExbD envelope complex to release iron chelates from their specific outer membrane receptors into the periplasm. Based on sequence similarities, the Bordetella pertussis tonB exbB exbD locus was identified on a cloned DNA fra...

Fuld beskrivelse

Na minha lista:
Bibliografiske detaljer
Main Authors: Pradel, Elizabeth, Guiso, Nicole, Menozzi, Franco D., Locht, Camille
Format: Artigo
Sprog:en
Udgivet: American Society for Microbiology 2000
Fag:
Molecular and Cellular Pathogenesis
Online adgang:https://ncbi.nlm.nih.gov/pmc/articles/PMC97367/
https://ncbi.nlm.nih.gov/pubmed/10722583
Tags: Tilføj Tag
Ingen Tags, Vær først til at tagge denne postø!
id pubmed-97367
record_format dspace
spelling pubmed-973672002-09-12 Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant Pradel, Elizabeth Guiso, Nicole Menozzi, Franco D. Locht, Camille Infect Immun Molecular and Cellular Pathogenesis In gram-negative bacteria, high-affinity iron uptake requires the TonB/ExbB/ExbD envelope complex to release iron chelates from their specific outer membrane receptors into the periplasm. Based on sequence similarities, the Bordetella pertussis tonB exbB exbD locus was identified on a cloned DNA fragment. The tight organization of the three genes suggests that they are cotranscribed. A putative Fur-binding sequence located upstream from tonB was detected in a Fur titration assay, indicating that the tonB exbB exbD operon may be Fur-repressed in high-iron growth conditions. Putative structural genes of the β-subunit of the histone-like protein HU and of a new two-component regulatory system were identified upstream from tonB and downstream from exbD, respectively. A B. pertussis ΔtonB exbB::Km(r) mutant was constructed by allelic exchange and characterized. The mutant was impaired for growth in low-iron medium in vitro and could not use ferrichrome, desferal, or hemin as iron sources. Levels of production of the major bacterial toxins and adhesins were similar in the TonB(+)/TonB(−) pair. The ΔtonB exbB mutant was still responsive to chemical modulators of virulence; thus, the BvgA/BvgS two-component system is not TonB dependent. Nevertheless, in vivo in the mouse respiratory infection model, the colonization ability of the mutant was reduced compared to the parental strain. American Society for Microbiology 2000-04 /pmc/articles/PMC97367/ /pubmed/10722583 Text en Copyright © 2000, American Society for Microbiology
institution US National Library of Medicine
collection PubMed Central
language en
format Article
topic Molecular and Cellular Pathogenesis
spellingShingle Molecular and Cellular Pathogenesis
Pradel, Elizabeth
Guiso, Nicole
Menozzi, Franco D.
Locht, Camille
Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant
description In gram-negative bacteria, high-affinity iron uptake requires the TonB/ExbB/ExbD envelope complex to release iron chelates from their specific outer membrane receptors into the periplasm. Based on sequence similarities, the Bordetella pertussis tonB exbB exbD locus was identified on a cloned DNA fragment. The tight organization of the three genes suggests that they are cotranscribed. A putative Fur-binding sequence located upstream from tonB was detected in a Fur titration assay, indicating that the tonB exbB exbD operon may be Fur-repressed in high-iron growth conditions. Putative structural genes of the β-subunit of the histone-like protein HU and of a new two-component regulatory system were identified upstream from tonB and downstream from exbD, respectively. A B. pertussis ΔtonB exbB::Km(r) mutant was constructed by allelic exchange and characterized. The mutant was impaired for growth in low-iron medium in vitro and could not use ferrichrome, desferal, or hemin as iron sources. Levels of production of the major bacterial toxins and adhesins were similar in the TonB(+)/TonB(−) pair. The ΔtonB exbB mutant was still responsive to chemical modulators of virulence; thus, the BvgA/BvgS two-component system is not TonB dependent. Nevertheless, in vivo in the mouse respiratory infection model, the colonization ability of the mutant was reduced compared to the parental strain.
author Pradel, Elizabeth
Guiso, Nicole
Menozzi, Franco D.
Locht, Camille
author_facet Pradel, Elizabeth
Guiso, Nicole
Menozzi, Franco D.
Locht, Camille
author_sort Pradel, Elizabeth
title Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant
title_short Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant
title_full Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant
title_fullStr Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant
title_full_unstemmed Bordetella pertussis TonB, a Bvg-Independent Virulence Determinant
title_sort bordetella pertussis tonb, a bvg-independent virulence determinant
publisher American Society for Microbiology
publisher_facet American Society for Microbiology
publishDate 2000
url https://ncbi.nlm.nih.gov/pmc/articles/PMC97367/
https://ncbi.nlm.nih.gov/pubmed/10722583
_version_ 1759030433380564992

Lignende værker