2CO7

Salmonella enterica SafA pilin in complex with the SafB chaperone (Type II)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history. 

Literature

Donor-Strand Exchange in Chaperone-Assisted Pilus Assembly Proceeds Through a Concerted Beta-Strand Displacement Mechanism

Remaut, H., Rose, R.J., Hannan, T.J., Hultgren, S.J., Radford, S.E., Ashcroft, A.E., Waksman, G.

(2006) Mol.Cell 22: 831

  • DOI: 10.1016/j.molcel.2006.05.033
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Gram-negative pathogens commonly use the chaperone-usher pathway to assemble adhesive multisubunit fibers on their surface. In the periplasm, subunits are stabilized by a chaperone that donates a beta strand to complement the subunits' truncated immu ...

    Gram-negative pathogens commonly use the chaperone-usher pathway to assemble adhesive multisubunit fibers on their surface. In the periplasm, subunits are stabilized by a chaperone that donates a beta strand to complement the subunits' truncated immunoglobulin-like fold. Pilus assembly proceeds through a "donor-strand exchange" (DSE) mechanism whereby this complementary beta strand is replaced by the N-terminal extension (Nte) of an incoming pilus subunit. Using X-ray crystallography and real-time electrospray ionization mass spectrometry (ESI-MS), we demonstrate that DSE requires the formation of a transient ternary complex between the chaperone-subunit complex and the Nte of the next subunit to be assembled. The process is crucially dependent on an initiation site (the P5 pocket) needed to recruit the incoming Nte. The data also suggest a capping reaction displacing DSE toward product formation. These results support a zip-in-zip-out mechanism for DSE and a catalytic role for the usher, the molecular platform at which pili are assembled.

    Organizational Affiliation: 

    Institute of Structural Molecular Biology at UCL/Birkbeck, Malet Street, London WC1E 7HX, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SAFA PILUS SUBUNIT
A
127Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 0 
Gene Names: safA
Find proteins for Q8ZRK4 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  Q8ZRK4
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
PUTATIVE FIMBRIAE ASSEMBLY CHAPERONE
B
221Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 0 
Gene Names: safB
Find proteins for Q8ZRK3 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  Q8ZRK3
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4
Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 114.388α = 90.00
b = 40.595β = 95.82
c = 72.039γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
PHASERphasing
MOSFLMdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots


View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-06-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.2: 2019-10-09
    Type: Data collection, Experimental preparation, Other