1C14

CRYSTAL STRUCTURE OF E COLI ENOYL REDUCTASE-NAD+-TRICLOSAN COMPLEX

• PDB DOI: https://doi.org/10.2210/pdb1C14/pdb

• Classification: OXIDOREDUCTASE
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1999-07-20 Released: 2000-07-20 
• Deposition Author(s): Qiu, X., Janson, C., Court, R., Smyth, M., Payne, D., Abdel-Meguid, S.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.263 
• R-Value Work: 0.199 
• R-Value Observed: 0.199 

Literature

Molecular basis for triclosan activity involves a flipping loop in the active site.

Qiu, X., Janson, C.A., Court, R.I., Smyth, M.G., Payne, D.J., Abdel-Meguid, S.S.

(1999) Protein Sci 8: 2529-2532

• PubMed: 10595560 
• DOI: https://doi.org/10.1110/ps.8.11.2529
• Primary Citation of Related Structures:  
  1C14


• PubMed Abstract: 
  

  The crystal structure of the Escherichia coli enoyl reductase-NAD+-triclosan complex has been determined at 2.5 A resolution. The Ile192-Ser198 loop is either disordered or in an open conformation in the previously reported structures of the enzyme. This loop adopts a closed conformation in our structure, forming van der Waals interactions with the inhibitor and hydrogen bonds with the bound NAD+ cofactor. The opening and closing of this flipping loop is likely an important factor in substrate or ligand recognition. The closed conformation of the loop appears to be a critical feature for the enhanced binding potency of triclosan, and a key component in future structure-based inhibitor design.

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Organizational Affiliation: 

Department of Structural Biology, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA. [e-mail]

Biological Assembly 1  

Global Symmetry: Dihedral - D2  (Explore in 3D)
Global Stoichiometry: Homo 4-mer - A4 

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

Macromolecule Content

• Total Structure Weight: 57.69 kDa 
• Atom Count: 4,161 
• Modelled Residue Count: 512 
• Deposited Residue Count: 524 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ENOYL REDUCTASE	A, B	262	Escherichia coli	Mutation(s): 0  EC: 1.3.1.9
UniProt
Find proteins for P0AEK4 (Escherichia coli (strain K12)) Explore P0AEK4  Go to UniProtKB:  P0AEK4

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NAD	C [auth A], E [auth B]	NICOTINAMIDE-ADENINE-DINUCLEOTIDE C21 H27 N7 O14 P2 BAWFJGJZGIEFAR-NNYOXOHSSA-N
TCL	D [auth A], F [auth B]	TRICLOSAN C12 H7 Cl3 O2 XEFQLINVKFYRCS-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
TCL	BindingDB:  1C14	Ki: 7.00e-3 (nM) from 1 assay(s)
		IC50: min: 5, max: 900 (nM) from 3 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.263 
• R-Value Work: 0.199 
• R-Value Observed: 0.199 
• Space Group: P 6₁ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 79	α = 90
b = 79	β = 90
c = 328.75	γ = 120

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
DENZO	data reduction
SCALEPACK	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2000-07-20 
Deposition Author(s): Qiu, X., Janson, C., Court, R., Smyth, M., Payne, D., Abdel-Meguid, S.

Revision History  

• Version 1.0: 2000-07-20
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance
• Version 1.3: 2024-02-07
  Changes: Data collection, Database references, Derived calculations