Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 89.6 kDa 
• Atom Count: 5,862 
• Modelled Residue Count: 661 
• Deposited Residue Count: 774 
• Unique protein chains: 1

 1KMO

Crystal structure of the Outer Membrane Transporter FecA

• PDB DOI:  https://doi.org/10.2210/pdb1KMO/pdb

• Classification: MEMBRANE PROTEIN
• Organism(s): Escherichia coli K-12
• Expression System: Escherichia coli
• Mutation(s): No 
• Membrane Protein: Yes  OPMPDBTMMemProtMDmpstruc


• Deposited: 2001-12-17 Released: 2002-03-06 
• Deposition Author(s): Ferguson, A.D., Chakraborty, R., Smith, B.S., Esser, L., van der Helm, D., Deisenhofer, J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.245 
• R-Value Work: 0.207 
• R-Value Observed: 0.207 

Literature

Structural basis of gating by the outer membrane transporter FecA.

Ferguson, A.D., Chakraborty, R., Smith, B.S., Esser, L., van der Helm, D., Deisenhofer, J.

(2002) Science 295: 1715-1719

• PubMed: 11872840 
• DOI: https://doi.org/10.1126/science.1067313
• Primary Citation of Related Structures:  
  1KMO, 1KMP


• PubMed Abstract: 
  

Siderophore-mediated acquisition systems facilitate iron uptake. We present the crystallographic structure of the integral outer membrane receptor FecA from Escherichia coli with and without ferric citrate at 2.5 and 2.0 angstrom resolution. FecA is composed of three distinct domains: the barrel, plug, and NH2-terminal extension. Binding of ferric citrate triggers a conformational change of the extracellular loops that close the external pocket of FecA. Ligand-induced allosteric transitions are propagated through the outer membrane by the plug domain, signaling the occupancy of the receptor in the periplasm. These data establish the structural basis of gating for receptors dependent on the cytoplasmic membrane protein TonB. By compiling available data for this family of receptors, we propose a mechanism for the energy-dependent transport of siderophores.

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Organizational Affiliation: 

Howard Hughes Medical Institute and Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Iron(III) dicitrate transport protein fecA	A	774	Escherichia coli K-12	Mutation(s): 0  Gene Names: fecA, b4291, JW4251 Membrane Entity: Yes
UniProt
Find proteins for P13036 (Escherichia coli (strain K12)) Explore P13036  Go to UniProtKB:  P13036

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
LDA	B [auth A], C [auth A], D [auth A], E [auth A], F [auth A], G [auth A], H [auth A], I [auth A], J [auth A], K [auth A], L [auth A], M [auth A], N [auth A], O [auth A], P [auth A], Q [auth A], R [auth A]	LAURYL DIMETHYLAMINE-N-OXIDE C14 H31 N O SYELZBGXAIXKHU-UHFFFAOYSA-N
HTO	S [auth A], T [auth A]	HEPTANE-1,2,3-TRIOL C7 H16 O3 HXYCHJFUBNTKQR-RNFRBKRXSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.245 
• R-Value Work: 0.207 
• R-Value Observed: 0.207 
• Space Group: P 2₁ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 117.083	α = 90
b = 88.086	β = 90
c = 94.578	γ = 90

Software Package:

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

Structure Validation

Entry History 

Deposition Data

• Released Date: 2002-03-06 
Deposition Author(s): Ferguson, A.D., Chakraborty, R., Smith, B.S., Esser, L., van der Helm, D., Deisenhofer, J.

Revision History  

• Version 1.0: 2002-03-06
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2017-10-11
  Changes: Refinement description