2RJZ

Crystal structure of the type 4 fimbrial biogenesis protein PilO from Pseudomonas aeruginosa


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Periplasmic domains of Pseudomonas aeruginosa PilN and PilO form a stable heterodimeric complex.

Sampaleanu, L.M.Bonanno, J.B.Ayers, M.Koo, J.Tammam, S.Burley, S.K.Almo, S.C.Burrows, L.L.Howell, P.L.

(2009) J.Mol.Biol. 394: 143-159

  • DOI: 10.1016/j.jmb.2009.09.037

  • PubMed Abstract: 
  • Type IV pili (T4P) are bacterial virulence factors responsible for attachment to surfaces and for twitching motility, a motion that involves a succession of pilus extension and retraction cycles. In the opportunistic pathogen Pseudomonas aeruginosa, ...

    Type IV pili (T4P) are bacterial virulence factors responsible for attachment to surfaces and for twitching motility, a motion that involves a succession of pilus extension and retraction cycles. In the opportunistic pathogen Pseudomonas aeruginosa, the PilM/N/O/P proteins are essential for T4P biogenesis, and genetic and biochemical analyses strongly suggest that they form an inner-membrane complex. Here, we show through co-expression and biochemical analysis that the periplasmic domains of PilN and PilO interact to form a heterodimer. The structure of residues 69-201 of the periplasmic domain of PilO was determined to 2.2 A resolution and reveals the presence of a homodimer in the asymmetric unit. Each monomer consists of two N-terminal coiled coils and a C-terminal ferredoxin-like domain. This structure was used to generate homology models of PilN and the PilN/O heterodimer. Our structural analysis suggests that in vivo PilN/O heterodimerization would require changes in the orientation of the first N-terminal coiled coil, which leads to two alternative models for the role of the transmembrane domains in the PilN/O interaction. Analysis of PilN/O orthologues in the type II secretion system EpsL/M revealed significant similarities in their secondary structures and the tertiary structures of PilO and EpsM, although the way these proteins interact to form inner-membrane complexes appears to be different in T4P and type II secretion. Our analysis suggests that PilN interacts directly, via its N-terminal tail, with the cytoplasmic protein PilM. This work shows a direct interaction between the periplasmic domains of PilN and PilO, with PilO playing a key role in the proper folding of PilN. Our results suggest that PilN/O heterodimers form the foundation of the inner-membrane PilM/N/O/P complex, which is critical for the assembly of a functional T4P complex.


    Organizational Affiliation

    Program in Molecular Structure and Function, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PilO protein
A, B
147Pseudomonas aeruginosaMutation(s): 0 
Gene Names: pilO
Find proteins for Q51353 (Pseudomonas aeruginosa)
Go to UniProtKB:  Q51353
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: 2.2 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.193 
  • Space Group: P 64
Unit Cell:
Length (Å)Angle (°)
a = 70.471α = 90.00
b = 70.471β = 90.00
c = 116.876γ = 120.00
Software Package:
Software NamePurpose
MAR345data collection
SCALAdata scaling
DENZOdata reduction
SHELXCDphasing
REFMACrefinement
PDB_EXTRACTdata extraction
SHELXEmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-11-06
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance
  • Version 1.2: 2017-10-25
    Type: Refinement description
  • Version 1.3: 2018-11-14
    Type: Data collection, Structure summary