Related Experiment Videos
A Porphyromonas gingivalis genetic locus encoding a heme transport system
N Slakeski1, S G Dashper, P Cook
1Oral Health Science Unit, School of Dental Science, University of Melbourne, 711 Elizabeth Street, Melbourne 3000, Victoria, Australia.
Oral Microbiology and Immunology
|January 12, 2001
Summary
Porphyromonas gingivalis requires hemin for growth. Researchers cloned and analyzed the tlr gene, essential for low hemin conditions, revealing a linked heme transport system (htrABCD) crucial for bacterial virulence.
Area of Science:
- Microbiology
- Molecular Biology
- Oral Health
Background:
- Porphyromonas gingivalis is linked to periodontitis.
- Hemin availability influences P. gingivalis virulence in vivo.
- The TonB-linked adhesin gene (tla) is essential for growth in low hemin concentrations.
Purpose of the Study:
- To clone and sequence the P. gingivalis TonB-linked outer membrane receptor gene, tlr.
- To investigate the genetic organization and potential function of genes associated with tlr.
- To understand the molecular mechanisms of hemin uptake in P. gingivalis.
Main Methods:
- Gene cloning and sequence analysis of P. gingivalis.
- Bioinformatic analysis of open reading frames and sequence similarity.
- mRNA analysis to determine gene cotranscription.
Main Results:
- The tlr gene, previously identified as tla, was cloned and sequenced.
- The tlr gene is located upstream of four cotranscribed genes (htrABCD).
- The htrABCD genes encode a putative ATP binding cassette transport system similar to bacterial heme transport systems.
Conclusions:
- The tlr gene and the htrABCD genes form a potential heme transport operon in P. gingivalis.
- This system is likely critical for P. gingivalis growth and virulence, particularly under conditions of limited hemin availability.