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Two Proteins Form a Heteromeric Bacterial Self-Recognition Complex in Which Variable Subdomains Determine
Lia Cardarelli1, Christina Saak1, Karine A Gibbs2
1Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
Mbio
|June 11, 2015
Summary
Two bacterial proteins, IdsD and IdsE, form a strain-specific complex crucial for bacterial self-recognition and social behavior in Proteus mirabilis.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Bacterial self-recognition mechanisms are genetically defined but biochemically poorly understood.
- Two proteins, IdsD and IdsE, in Proteus mirabilis are known genetic determinants of strain identity.
Purpose of the Study:
- To elucidate the molecular and biochemical mechanisms of bacterial self-recognition mediated by IdsD and IdsE.
- To investigate the biochemical properties and interaction specificity of IdsD and IdsE proteins.
Main Methods:
- Investigated the formation of a heterotypic complex between IdsD and IdsE.
- Analyzed the strain- and allele-specificity of IdsD-IdsE binding in vitro.
- Correlated in vitro binding affinities with in vivo population identity.
Main Results:
- IdsD and IdsE form a heterotypic complex independently of other self-recognition proteins.
- The IdsD-IdsE interaction is strain- and allele-specific, with specificity encoded in membrane-spanning subdomains.
- In vitro binding specificity directly correlates with in vivo bacterial population identity.
Conclusions:
- The IdsD-IdsE complex formation is a key molecular mechanism underlying bacterial self-recognition in P. mirabilis.
- This molecular recognition event likely drives bacterial population sociality and identity.
- Understanding IdsD-IdsE interactions provides insight into bacterial social behavior and population dynamics.
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