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Purification of a High Molecular Mass Protein in Streptococcus mutans
Published on: September 14, 2019
A mechanism for extremely weak SpaP-expression in Streptococcus mutans strain Z1
Yutaka Sato1, Kazuko Okamoto-Shibayama, Toshifumi Azuma
1Department of Biochemistry, Tokyo Dental College, Chiba City, Japan.
Journal of Oral Microbiology
|May 5, 2011
Summary
A 20 bp deletion in the promoter region of the Streptococcus mutans spaP gene significantly reduces SpaP protein expression. This finding explains weak SpaP-expression in certain S. mutans strains, impacting bacterial adhesion.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Streptococcus mutans surface protein antigen (SpaP) is crucial for initial tooth surface attachment.
- Recent studies identified S. mutans strains with diminished SpaP expression.
- Strain Z1 exhibits notably low SpaP levels compared to reference strains.
Purpose of the Study:
- Investigate the molecular mechanism behind reduced SpaP expression in S. mutans strain Z1.
- Analyze the spaP gene region in strain Z1 to identify genetic variations.
- Determine the impact of identified variations on SpaP protein production.
Main Methods:
- Polymerase chain reaction (PCR) amplification and sequencing of the spaP gene region in strain Z1.
- Construction of allelic exchange mutants between S. mutans strains Z1 and UA159.
- Detection and quantification of SpaP protein expression using SDS-PAGE with Coomasie Brilliant Blue staining and Western blot analysis.
Main Results:
- The spaP coding sequence in strain Z1 was found to be intact.
- A 20 bp deletion was identified in the region upstream of the spaP gene in strain Z1 compared to strain UA159.
- Allelic replacement experiments confirmed that the deletion in the promoter region directly correlates with reduced SpaP expression.
Conclusions:
- The reduced expression of SpaP in S. mutans strain Z1 is attributed to a 20 bp deletion within its spaP gene promoter region.
- This genetic alteration in the promoter significantly impacts SpaP protein levels.
- Understanding this mechanism is vital for comprehending S. mutans adhesion and virulence.
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