Biological Assembly 1  

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

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by PQS (software)

Biological Assembly 2  

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

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 2 assigned by authors and generated by PQS (software)

Macromolecule Content

• Total Structure Weight: 19.35 kDa 
• Atom Count: 1032 
• Modelled Residue Count: 123 
• Deposited Residue Count: 170 
• Unique protein chains: 1

2CA5

MxiH needle protein of Shigella Flexneri (monomeric form, residues 1- 78)

• PDB DOI: 10.2210/pdb2CA5/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Shigella flexneri
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2005-12-16 Released: 2006-08-07 
• Deposition Author(s): Deane, J.E., Roversi, P., Cordes, F.S., Johnson, S., Kenjale, R., Picking, W.L., Picking, W.D., Blocker, A.J., Lea, S.M.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Work: 0.194 
• R-Value Observed: 0.194 

Literature

Molecular Model of a Type III Secretion System Needle: Implications for Host-Cell Sensing

Deane, J.E., Roversi, P., Cordes, F.S., Johnson, S., Kenjale, R., Daniell, S., Booy, F., Picking, W.L., Picking, W.D., Blocker, A.J., Lea, S.M.

(2006) Proc Natl Acad Sci U S A 103: 12529

• PubMed: 16888041 
• DOI: 10.1073/pnas.0602689103
• Primary Citation of Related Structures:  
  2CA5, 2V6L


• PubMed Abstract: 
  

Type III secretion systems are essential virulence determinants for many Gram-negative bacterial pathogens. The type III secretion system consists of cytoplasmic, transmembrane, and extracellular domains. The extracellular domain is a hollow needle protruding above the bacterial surface and is held within a basal body that traverses both bacterial membranes. Effector proteins are translocated, via this external needle, directly into host cells, where they subvert normal cell functions to aid infection. Physical contact with host cells initiates secretion and leads to formation of a pore, thought to be contiguous with the needle channel, in the host-cell membrane. Here, we report the crystal structure of the Shigella flexneri needle subunit MxiH and a complete model for the needle assembly built into our three-dimensional EM reconstruction. The model, combined with mutagenesis data, reveals that signaling of host-cell contact is relayed through the needle via intersubunit contacts and suggests a mode of binding for a tip complex.

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Related Citations: 

• Expression, Purification, Crystallization and Preliminary Crystallographic Analysis of Mxih, a Subunit of the Shigella Flexneri Type III Secretion System Needle.
  Deane, J.E., Cordes, F.S., Roversi, P., Johnson, S., Kenjale, R., Picking, W.D., Picking, W.L., Lea, S.M., Blocker, A.
  (2006) Acta Crystallogr Sect F Struct Biol Cryst Commun 62: 302

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Organizational Affiliation: 

Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
MXIH	A, B	85	Shigella flexneri	Mutation(s): 0  Gene Names: mxiH, CP0137
UniProt
Find proteins for P0A223 (Shigella flexneri) Explore P0A223  Go to UniProtKB:  P0A223

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GOL	E [auth A]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
IPA	C [auth A], D [auth A]	ISOPROPYL ALCOHOL C3 H8 O KFZMGEQAYNKOFK-UHFFFAOYSA-N
NA	F [auth A], G [auth B]	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Work: 0.194 
• R-Value Observed: 0.194 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 183.203	α = 90
b = 28.123	β = 96.47
c = 27.723	γ = 90

Software Package:

Software Name	Purpose
SIGMAA	model building
SCALA	data scaling
SHARP	phasing
SOLOMON	phasing
DM	phasing
SIGMAA	phasing
TNT	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2005-12-16 
• Released Date: 2006-08-07 
Deposition Author(s): Deane, J.E., Roversi, P., Cordes, F.S., Johnson, S., Kenjale, R., Picking, W.L., Picking, W.D., Blocker, A.J., Lea, S.M.

Revision History  

• Version 1.0: 2006-08-07
  Type: Initial release
  
• Version 1.1: 2011-05-08
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance