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Structure of the calcium dependent type 2 secretion pseudopilus
- Source :
- Nature Microbiology, Nature Microbiology, Nature Publishing Group, 2017, ⟨10.1038/s41564-017-0041-2⟩, Nature Microbiology, 2017, ⟨10.1038/s41564-017-0041-2⟩, Nature microbiology
- Publication Year :
- 2017
- Publisher :
- HAL CCSD, 2017.
-
Abstract
- Many Gram-negative bacteria use type 2 secretion systems (T2SSs) to secrete proteins involved in virulence and adaptation. Transport of folded proteins via T2SS nanomachines requires the assembly of inner membrane-anchored fibres called pseudopili. Although efficient pseudopilus assembly is essential for protein secretion, structure-based functional analyses are required to unravel the mechanistic link between these processes. Here, we report an atomic model for a T2SS pseudopilus from Klebsiella oxytoca, obtained by fitting the NMR structure of its calcium-bound subunit PulG into the ~5-A-resolution cryo-electron microscopy reconstruction of assembled fibres. This structure reveals the comprehensive network of inter-subunit contacts and unexpected features, including a disordered central region of the PulG helical stem, and highly flexible C-terminal residues on the fibre surface. NMR, mutagenesis and functional analyses highlight the key role of calcium in PulG folding and stability. Fibre disassembly in the absence of calcium provides a basis for pseudopilus length control, essential for protein secretion, and supports the Archimedes screw model for the type 2 secretion mechanism. An atomic model for a type 2 secretion system pseudopilus from Klebsiella oxytoca reveals a comprehensive network of inter-subunit contacts while mutational and functional analyses highlight the role of calcium in PulG folding and stability.
- Subjects :
- Models, Molecular
0301 basic medicine
Microbiology (medical)
Magnetic Resonance Spectroscopy
Protein Conformation
Protein subunit
Immunology
chemistry.chemical_element
Biology
Calcium
Applied Microbiology and Biotechnology
Microbiology
Article
03 medical and health sciences
Protein structure
Bacterial Proteins
protein folding
Gram-Negative Bacteria
Type II Secretion Systems
Escherichia coli
Genetics
Secretion
Binding site
ComputingMilieux_MISCELLANEOUS
type 2 secretion system
solution NMR
Binding Sites
calcium
Protein Stability
Circular Dichroism
Cryoelectron Microscopy
Klebsiella oxytoca
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology
Cell Biology
Transport protein
Folding (chemistry)
cryoEM
Protein Transport
type 4
030104 developmental biology
chemistry
Fimbriae, Bacterial
Isotope Labeling
Biophysics
Protein folding
type 4 filaments
Subjects
Details
- Language :
- English
- ISSN :
- 20585276
- Database :
- OpenAIRE
- Journal :
- Nature Microbiology, Nature Microbiology, Nature Publishing Group, 2017, ⟨10.1038/s41564-017-0041-2⟩, Nature Microbiology, 2017, ⟨10.1038/s41564-017-0041-2⟩, Nature microbiology
- Accession number :
- edsair.doi.dedup.....5a6e370c388c87d35bc379a2282a96fe