2Z6I

Crystal Structure of S. pneumoniae Enoyl-Acyl Carrier Protein Reductase (FabK)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal structure of enoyl-acyl carrier protein reductase (FabK) from Streptococcus pneumoniae reveals the binding mode of an inhibitor.

Saito, J.Yamada, M.Watanabe, T.Iida, M.Kitagawa, H.Takahata, S.Ozawa, T.Takeuchi, Y.Ohsawa, F.

(2008) Protein Sci. 17: 691-699

  • DOI: 10.1110/ps.073288808
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Enoyl-acyl carrier protein (ACP) reductases are critical for bacterial type II fatty acid biosynthesis and thus are attractive targets for developing novel antibiotics. We determined the crystal structure of enoyl-ACP reductase (FabK) from Streptococ ...

    Enoyl-acyl carrier protein (ACP) reductases are critical for bacterial type II fatty acid biosynthesis and thus are attractive targets for developing novel antibiotics. We determined the crystal structure of enoyl-ACP reductase (FabK) from Streptococcus pneumoniae at 1.7 A resolution. There was one dimer per asymmetric unit. Each subunit formed a triose phosphate isomerase (TIM) barrel structure, and flavin mononucleotide (FMN) was bound as a cofactor in the active site. The overall structure was similar to the enoyl-ACP reductase (ER) of fungal fatty acid synthase and to 2-nitropropane dioxygenase (2-ND) from Pseudomonas aeruginosa, although there were some differences among these structures. We determined the crystal structure of FabK in complex with a phenylimidazole derivative inhibitor to envision the binding site interactions. The crystal structure reveals that the inhibitor binds to a hydrophobic pocket in the active site of FabK, and this is accompanied by induced-fit movements of two loop regions. The thiazole ring and part of the ureido moiety of the inhibitor are involved in a face-to-face pi-pi stacking interaction with the isoalloxazine ring of FMN. The side-chain conformation of the proposed catalytic residue, His144, changes upon complex formation. Lineweaver-Burk plots indicate that the inhibitor binds competitively with respect to NADH, and uncompetitively with respect to crotonoyl coenzyme A. We propose that the primary basis of the inhibitory activity is competition with NADH for binding to FabK, which is the first step of the two-step ping-pong catalytic mechanism.


    Organizational Affiliation

    Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., Kohoku-ku, Yokohama 222-8567, Japan. jun_saito@meiji.co.jp




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Trans-2-enoyl-ACP reductase II
A, B
332Streptococcus pneumoniaeMutation(s): 0 
Gene Names: fabK (fabK_1)
EC: 1.3.1.9, 1.13.12.16, 1.3.-.-
Find proteins for Q9FBC5 (Streptococcus pneumoniae)
Go to UniProtKB:  Q9FBC5
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMN
Query on FMN

Download SDF File 
Download CCD File 
A, B
FLAVIN MONONUCLEOTIDE
RIBOFLAVIN MONOPHOSPHATE
C17 H21 N4 O9 P
FVTCRASFADXXNN-SCRDCRAPSA-N
 Ligand Interaction
CA
Query on CA

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Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
MPD
Query on MPD

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Download CCD File 
A
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.202 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 50.386α = 90.00
b = 126.895β = 111.54
c = 53.335γ = 90.00
Software Package:
Software NamePurpose
CrystalCleardata scaling
REFMACrefinement
SOLVEphasing
CrystalCleardata reduction
BSSdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-04-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance