1N12

Crystal structure of the PapE (N-terminal-deleted) pilus subunit bound to a peptide corresponding to the N-terminal extension of the PapK pilus subunit (residues 1-11) from uropathogenic E. coli

• PDB DOI: https://doi.org/10.2210/pdb1N12/pdb

• Classification: CHAPERONE
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2002-10-16 Released: 2002-12-11 
• Deposition Author(s): Sauer, F.G., Pinkner, J.S., Waksman, G., Hultgren, S.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.87 Å
• R-Value Free: 0.249 
• R-Value Work: 0.208 
• R-Value Observed: 0.208 

Literature

Chaperone priming of pilus subunits facilitates a topological transition that drives fiber formation

Sauer, F.G., Pinkner, J.S., Waksman, G., Hultgren, S.J.

(2002) Cell 111: 543-551

• PubMed: 12437927 
• DOI: https://doi.org/10.1016/s0092-8674(02)01050-4
• Primary Citation of Related Structures:  
  1N0L, 1N12


• PubMed Abstract: 
  

  Periplasmic chaperones direct the assembly of adhesive, multi-subunit pilus fibers that play critical roles in bacterial pathogenesis. Pilus assembly occurs via a donor strand exchange mechanism in which the N-terminal extension of one subunit replaces the chaperone G(1) strand that transiently occupies a groove in the neighboring subunit. Here, we show that the chaperone primes the subunit for assembly by holding the groove in an open, activated conformation. During donor strand exchange, the subunit undergoes a topological transition that triggers the closure of the groove and seals the N-terminal extension in place. It is this topological transition, made possible only by the priming action of the chaperone that drives subunit assembly into the fiber.

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Organizational Affiliation: 

Department of Molecular Microbiology, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63105, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

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

Biological Assembly 2  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

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

Macromolecule Content

• Total Structure Weight: 32.08 kDa 
• Atom Count: 2,395 
• Modelled Residue Count: 296 
• Deposited Residue Count: 298 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
mature Fimbrial protein PapE	A, C	138	Escherichia coli	Mutation(s): 3
UniProt
Find proteins for P08407 (Escherichia coli) Explore P08407  Go to UniProtKB:  P08407

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Peptide corresponding to the N-terminal extension of protein PapK	B, D	11	N/A	Mutation(s): 0
UniProt
Find proteins for P42191 (Escherichia coli) Explore P42191  Go to UniProtKB:  P42191

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A, C	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.87 Å
• R-Value Free: 0.249 
• R-Value Work: 0.208 
• R-Value Observed: 0.208 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 25.254	α = 90
b = 91.922	β = 99.26
c = 51.244	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
SCALEPACK	data scaling
CNS	refinement
HKL-2000	data reduction
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2002-12-11 
Deposition Author(s): Sauer, F.G., Pinkner, J.S., Waksman, G., Hultgren, S.J.

Revision History  

• Version 1.0: 2002-12-11
  Type: Initial release
  
• Version 1.1: 2008-04-28
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-10-09
  Changes: Data collection, Database references, Derived calculations, Structure summary