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Following Cell-fate in E. coli After Infection by Phage Lambda
Published on: October 14, 2011
The phage lambda major tail protein structure reveals a common evolution for long-tailed phages and the type VI
Lisa G Pell1, Voula Kanelis, Logan W Donaldson
1Department of Biochemistry, University of Toronto, Medical Sciences Building, Toronto, ON M5S 1A8, Canada.
Summary
This study reveals the structure of a key phage lambda tail protein (gpV), showing its similarity to proteins in contractile-tailed phages and bacterial secretion systems. This suggests a shared evolutionary origin for these distinct biological structures.
Area of Science:
- Structural biology
- Molecular evolution
- Microbiology
Background:
- Bacteriophages utilize long tails for genome delivery.
- Phage tail proteins are crucial for infection and structure.
- The bacterial type VI secretion system shares some protein components with phages.
Purpose of the Study:
- To determine the solution structure of the N-terminal domain of phage lambda's gpV protein.
- To investigate the evolutionary relationship between phage tail structures and bacterial secretion systems.
- To propose a polymerization mechanism for gpV based on structural similarities.
Main Methods:
- Solution structure determination of the gpV N-terminal domain.
- Comparative structural analysis with known phage and bacterial secretion system proteins.
- Modeling of gpV polymerization based on structural data and functional analogies.
Main Results:
- The gpV N-terminal domain structure is highly similar to tail tube proteins of contractile-tailed phages.
- Remarkable structural similarity was observed between gpV and Hcp1, a component of the bacterial type VI secretion system.
- Evidence supports an evolutionary link between noncontractile phage tails, contractile phage tails, and the type VI secretion system.
Conclusions:
- The structural data provide the first direct evidence for an evolutionary connection between distinct phage tail types.
- Phage tails and bacterial type VI secretion systems likely share a common evolutionary origin.
- A polymerization model for gpV is proposed, involving disorder-to-order transitions, using Hcp1 as a structural template.
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