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Yersinia pestis YopM: thrombin binding and overexpression
1Department of Microbiology and Immunology, Chandler Medical Center, University of Kentucky, Lexington 40536-0084.
Infection and Immunity
|December 1, 1992
Summary
Yersinia pestis YopM protein binds to human alpha-thrombin and inhibits platelet aggregation. Its expression is regulated by a DNA structure upstream of the yopM gene.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Yersinia pestis YopM is essential for virulence in mice.
- YopM shares homology with the thrombin-binding domain of platelet receptor GPIb alpha.
Purpose of the Study:
- To investigate the interaction of Yersinia pestis YopM with human thrombin.
- To characterize the functional consequences of YopM binding.
- To identify regulatory elements controlling yopM gene expression.
Main Methods:
- Protein purification of YopM.
- Dot blot and chemical cross-linking assays to detect YopM-thrombin binding.
- Platelet aggregation assays to assess functional activity.
- Microsequencing of YopM.
- DNA sequencing and deletional analysis to study yopM gene regulation.
Main Results:
- YopM directly binds to human alpha-thrombin but not prothrombin.
- Native YopM inhibits thrombin-induced platelet aggregation.
- YopM is not processed at the N terminus.
- A DNA structure 5' to yopM moderates its expression, independent of identified ORFs and repeat sequences.
Conclusions:
- Yersinia pestis YopM interacts with human alpha-thrombin, inhibiting platelet aggregation, suggesting a role in virulence.
- YopM expression is regulated by upstream DNA elements, distinct from previously identified regulatory mechanisms.