1ENZ

CRYSTAL STRUCTURE AND FUNCTION OF THE ISONIAZID TARGET OF MYCOBACTERIUM TUBERCULOSIS

• PDB DOI: https://doi.org/10.2210/pdb1ENZ/pdb

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


• Deposited: 1995-01-27 Released: 1996-01-29 
• Deposition Author(s): Dessen, A., Quemard, A., Blanchard, J.S., Jacobs Jr., W.R., Sacchettini, J.C., TB Structural Genomics Consortium (TBSGC)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.70 Å
• R-Value Work: 0.193 
• R-Value Observed: 0.193 

Literature

Crystal structure and function of the isoniazid target of Mycobacterium tuberculosis.

Dessen, A., Quemard, A., Blanchard, J.S., Jacobs Jr., W.R., Sacchettini, J.C.

(1995) Science 267: 1638-1641

• PubMed: 7886450 
• DOI: https://doi.org/10.1126/science.7886450
• Primary Citation of Related Structures:  
  1ENY, 1ENZ


• PubMed Abstract: 
  

  Resistance to isoniazid in Mycobacterium tuberculosis can be mediated by substitution of alanine for serine 94 in the InhA protein, the drug's primary target. InhA was shown to catalyze the beta-nicotinamide adenine dinucleotide (NADH)-specific reduction of 2-trans-enoyl-acyl carrier protein, an essential step in fatty acid elongation. Kinetic analyses suggested that isoniazid resistance is due to a decreased affinity of the mutant protein for NADH. The three-dimensional structures of wild-type and mutant InhA, refined to 2.2 and 2.7 angstroms, respectively, revealed that drug resistance is directly related to a perturbation in the hydrogen-bonding network that stabilizes NADH binding.

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Organizational Affiliation: 

Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

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

Biological Assembly 2  

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

Biological assembly 2 generated by PISA,PQS (software)

Macromolecule Content

• Total Structure Weight: 29.04 kDa 
• Atom Count: 2,085 
• Modelled Residue Count: 268 
• Deposited Residue Count: 268 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ENOYL-ACYL CARRIER PROTEIN (ACP) REDUCTASE	A	268	Mycobacterium tuberculosis	Mutation(s): 0  EC: 1.3.1.9
UniProt
Find proteins for P9WGR1 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)) Explore P9WGR1  Go to UniProtKB:  P9WGR1

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NAD	B [auth A]	NICOTINAMIDE-ADENINE-DINUCLEOTIDE C21 H27 N7 O14 P2 BAWFJGJZGIEFAR-NNYOXOHSSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.70 Å
• R-Value Work: 0.193 
• R-Value Observed: 0.193 
• Space Group: P 6₂ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 100.14	α = 90
b = 100.14	β = 90
c = 139.95	γ = 120

Software Package:

Software Name	Purpose
X-PLOR	model building
TNT	refinement
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1996-01-29 
Deposition Author(s): Dessen, A., Quemard, A., Blanchard, J.S., Jacobs Jr., W.R., Sacchettini, J.C., TB Structural Genomics Consortium (TBSGC)

Revision History  

• Version 1.0: 1996-01-29
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance
• Version 1.3: 2019-07-17
  Changes: Data collection, Other, Refinement description
• Version 1.4: 2019-08-14
  Changes: Data collection, Refinement description
• Version 1.5: 2024-02-07
  Changes: Data collection, Database references, Derived calculations