7FC8

Crystal structure of the Apo enoyl-ACP-reductase (FabI) from Moraxella catarrhalis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.38 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.203 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Biochemical and structural basis for Moraxella catarrhalis enoyl-acyl carrier protein reductase (FabI) inhibition by triclosan and estradiol.

Katiki, M.Neetu, N.Pratap, S.Kumar, P.

(2022) Biochimie 198: 8-22

  • DOI: https://doi.org/10.1016/j.biochi.2022.02.008
  • Primary Citation of Related Structures:  
    7F44, 7FC8, 7FCM

  • PubMed Abstract: 

    The enoyl-acyl carrier protein reductase (ENR) is an established drug target and catalyzes the last reduction step of the fatty acid elongation cycle. Here, we report the crystal structures of FabI from Moraxella catarrhalis (McFabI) in the apo form, binary complex with NAD+ and ternary complex with NAD  +  -triclosan (TCL) determined at 2.36, 2.12 and 2.22 Å resolutions, respectively. The comparative study of these three structures revealed three different conformational states for the substrate-binding loop (SBL), including an unstructured intermediate, a structured intermediate and a closed conformation in the apo, binary and ternary complex forms, respectively; indicating the flexibility of SBL during the ligand binding. Virtual screening has suggested that estradiol cypionate may be a potential inhibitor of McFabI. Subsequently, estradiol (EST), the natural form of estradiol cypionate, was assessed for its FabI-binding and -inhibition properties. In vitro studies demonstrated that TCL and EST bind to McFabI with high affinity (K D  = 0.038 ± 0.004 and 5 ± 0.06 μM respectively) and inhibit its activity (K i  = 62.93 ± 3.95 nM and 25.97 ± 1.93 μM respectively) and suppress the growth of M. catarrhalis. These findings reveal that TCL and EST inhibit the McFabI activity and thereby affect cell growth. This study suggests that estradiol may be exploited as a novel scaffold for the designing and development of more potential FabI inhibitors.


  • Organizational Affiliation

    Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Enoyl-[acyl-carrier-protein] reductase [NADH]287Moraxella catarrhalis BBH18Mutation(s): 1 
Gene Names: fabIMCR_1078
EC: 1.3.1.9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download Ideal Coordinates CCD File 
B [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.38 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.203 
  • Space Group: P 42 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 74.982α = 90
b = 74.982β = 90
c = 101.461γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing
PDB_EXTRACTdata extraction

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Department of Biotechnology (DBT, India)IndiaBIC/12(29)/2013

Revision History  (Full details and data files)

  • Version 1.0: 2022-07-20
    Type: Initial release
  • Version 1.1: 2023-11-29
    Changes: Data collection, Refinement description
  • Version 1.2: 2024-01-31
    Changes: Database references