Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report

Global Symmetry: Helical - H  (3D View)
Global Stoichiometry: Homo 20-mer - A20 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: microscopy

Macromolecule Content

• Total Structure Weight: 182.62 kDa 
• Atom Count: 12220 
• Modelled Residue Count: 1560 
• Deposited Residue Count: 1660 
• Unique protein chains: 1

6OFE

Helical reconstruction of Type III Secretion System Needle filament mutant-PrgI S49A

• PDB DOI: 10.2210/pdb6OFE/pdb
• EM Map EMD-20043: EMDB EMDataResource

• Classification: PROTEIN TRANSPORT
• Organism(s): Salmonella enterica subsp. enterica serovar Typhimurium str. SL1344
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2019-03-29 Released: 2019-07-10 
• Deposition Author(s): Guo, E.Z., Galan, J.E.
• Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.61 Å
• Aggregation State: FILAMENT 
• Reconstruction Method: HELICAL 

Literature

A polymorphic helix of a Salmonella needle protein relays signals defining distinct steps in type III secretion.

Guo, E.Z., Desrosiers, D.C., Zalesak, J., Tolchard, J., Berbon, M., Habenstein, B., Marlovits, T., Loquet, A., Galan, J.E.

(2019) PLoS Biol 17: e3000351-e3000351

• PubMed: 31260457 
• DOI: 10.1371/journal.pbio.3000351
• Primary Citation of Related Structures:  
  6OFE, 6OFF, 6OFG, 6OFH


• PubMed Abstract: 
  

Type III protein-secretion machines are essential for the interactions of many pathogenic or symbiotic bacterial species with their respective eukaryotic hosts. The core component of these machines is the injectisome, a multiprotein complex that mediates the selection of substrates, their passage through the bacterial envelope, and ultimately their delivery into eukaryotic target cells. The injectisome is composed of a large cytoplasmic complex or sorting platform, a multiring base embedded in the bacterial envelope, and a needle-like filament that protrudes several nanometers from the bacterial surface and is capped at its distal end by the tip complex. A characteristic feature of these machines is that their activity is stimulated by contact with target host cells. The sensing of target cells, thought to be mediated by the distal tip of the needle filament, generates an activating signal that must be transduced to the secretion machine by the needle filament. Here, through a multidisciplinary approach, including solid-state NMR (SSNMR) and cryo electron microscopy (cryo-EM) analyses, we have identified critical residues of the needle filament protein of a Salmonella Typhimurium type III secretion system that are involved in the regulation of the activity of the secretion machine. We found that mutations in the needle filament protein result in various specific phenotypes associated with different steps in the type III secretion process. More specifically, these studies reveal an important role for a polymorphic helix of the needle filament protein and the residues that line the lumen of its central channel in the control of type III secretion.

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Organizational Affiliation: 

Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Protein PrgI	Q [auth A], R [auth B], S [auth C], P [auth D], T [auth E], K [auth F], L [auth G], M [auth H], N [auth I], O [auth J], F [auth K], G [auth L], H [auth M], I [auth N], J [auth O], A [auth P], B [auth Q], C [auth R], D [auth S], E [auth T]	83	Salmonella enterica subsp. enterica serovar Typhimurium str. SL1344	Mutation(s): 1  Gene Names: prgI, SL1344_2853
UniProt
Find proteins for P41784 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)) Explore P41784  Go to UniProtKB:  P41784

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.61 Å
• Aggregation State: FILAMENT 
• Reconstruction Method: HELICAL 

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2019-03-29 
• Released Date: 2019-07-10 
Deposition Author(s): Guo, E.Z., Galan, J.E.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)	United States	AI030492

Revision History  

• Version 1.0: 2019-07-10
  Type: Initial release
  
• Version 1.1: 2019-12-18
  Changes: Author supporting evidence