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The type II secretion system - a dynamic fiber assembly nanomachine
Manuel Campos1, David A Cisneros, Mangayarkarasi Nivaskumar
1Institut Pasteur, Molecular Genetics Unit, Department of Microbiology, 75015 Paris, France.
Research in Microbiology
|April 2, 2013
Summary
Type II secretion systems (T2SSs) assemble protein-secreting pseudopili using a conserved ATP-powered machine. Studying these systems and related fiber assemblies offers insights into their function and dynamics.
Area of Science:
- Microbiology
- Molecular Biology
- Structural Biology
Background:
- Type II secretion systems (T2SSs) are crucial for protein secretion in bacteria.
- T2SSs share structural and evolutionary links with archaeal flagella, pili, and type IV pili.
- These systems utilize a conserved ATP-powered machinery for assembling helical fibers.
Purpose of the Study:
- To review recent advancements in pseudopilus structure and biogenesis.
- To explore mechanistic models of pseudopilus function in protein secretion.
- To compare T2SSs with related fiber assembly nanomachines for functional insights.
Main Methods:
- Comparative analysis of T2SSs and related systems.
- Review of recent structural and biogenesis studies.
- Discussion of mechanistic models for pseudopilus function.
Main Results:
- T2SSs assemble pseudopili, periplasmic filaments essential for extracellular protein secretion.
- Conserved machinery underlies the assembly of various helical fibers across different systems.
- Pseudopili play a key role in secreting folded periplasmic proteins.
Conclusions:
- Understanding pseudopilus structure and biogenesis is key to T2SS function.
- Comparative studies illuminate the functional specificities and dynamics of these nanomachines.
- Mechanistic insights into pseudopilus function advance our knowledge of bacterial protein secretion.
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