3TUL

Crystal structure of N-terminal region of Type III Secretion Major Translocator SipB (residues 82-226)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.79 Å
  • R-Value Free: 0.316 
  • R-Value Work: 0.298 
  • R-Value Observed: 0.299 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The Structures of Coiled-Coil Domains from Type III Secretion System Translocators Reveal Homology to Pore-Forming Toxins.

Barta, M.L.Dickenson, N.E.Patil, M.Keightley, A.Wyckoff, G.J.Picking, W.D.Picking, W.L.Geisbrecht, B.V.

(2012) J Mol Biol 417: 395-405

  • DOI: 10.1016/j.jmb.2012.01.026
  • Primary Citation of Related Structures:  
    3U0C, 3TUL

  • PubMed Abstract: 
  • Many pathogenic Gram-negative bacteria utilize type III secretion systems (T3SSs) to alter the normal functions of target cells. Shigella flexneri uses its T3SS to invade human intestinal cells to cause bacillary dysentery (shigellosis) that is respo ...

    Many pathogenic Gram-negative bacteria utilize type III secretion systems (T3SSs) to alter the normal functions of target cells. Shigella flexneri uses its T3SS to invade human intestinal cells to cause bacillary dysentery (shigellosis) that is responsible for over one million deaths per year. The Shigella type III secretion apparatus is composed of a basal body spanning both bacterial membranes and an exposed oligomeric needle. Host altering effectors are secreted through this energized unidirectional conduit to promote bacterial invasion. The active needle tip complex of S. flexneri is composed of a tip protein, IpaD, and two pore-forming translocators, IpaB and IpaC. While the atomic structure of IpaD has been elucidated and studied, structural data on the hydrophobic translocators from the T3SS family remain elusive. We present here the crystal structures of a protease-stable fragment identified within the N-terminal regions of IpaB from S. flexneri and SipB from Salmonella enterica serovar Typhimurium determined at 2.1 Å and 2.8 Å limiting resolution, respectively. These newly identified domains are composed of extended-length (114 Å in IpaB and 71 Å in SipB) coiled-coil motifs that display a high degree of structural homology to one another despite the fact that they share only 21% sequence identity. Further structural comparisons also reveal substantial similarity to the coiled-coil regions of pore-forming proteins from other Gram-negative pathogens, notably, colicin Ia. This suggests that these mechanistically separate and functionally distinct membrane-targeting proteins may have diverged from a common ancestor during the course of pathogen-specific evolutionary events.


    Organizational Affiliation

    School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cell invasion protein sipBABCD158Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
Gene Names: sipBsspBSTM2885
Find proteins for Q56019 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore Q56019 
Go to UniProtKB:  Q56019
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A,B,C,DL-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.79 Å
  • R-Value Free: 0.316 
  • R-Value Work: 0.298 
  • R-Value Observed: 0.299 
  • Space Group: P 21 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 159.154α = 90
b = 51.144β = 90
c = 84.646γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
SOLVEphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-02-15
    Type: Initial release
  • Version 1.1: 2012-02-22
    Changes: Database references
  • Version 1.2: 2012-03-28
    Changes: Database references