2I3G

Crystal structure of N-Acetyl-gamma-Glutamyl-Phosphate Reductase (Rv1652) from Mycobacterium tuberculosis in complex with NADP+.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.163 

Starting Model: experimental
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Literature

Crystal Structure of N-acetyl-gamma-glutamyl-phosphate Reductase from Mycobacterium tuberculosis in Complex with NADP(+).

Cherney, L.T.Cherney, M.M.Garen, C.R.Niu, C.Moradian, F.James, M.N.G.

(2007) J Mol Biol 367: 1357-1369

  • DOI: https://doi.org/10.1016/j.jmb.2007.01.033
  • Primary Citation of Related Structures:  
    2I3A, 2I3G, 2NQT

  • PubMed Abstract: 

    The enzyme N-acetyl-gamma-glutamyl-phosphate reductase (AGPR) catalyzes the nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reductive dephosphorylation of N-acetyl-gamma-glutamyl-phosphate to N-acetylglutamate-gamma-semialdehyde. This reaction is part of the arginine biosynthetic pathway that is essential for some microorganisms and plants, in particular, for Mycobacterium tuberculosis (Mtb). The structures of apo MtbAGPR in the space groups P2(1)2(1)2(1) and C2 and the structure of MtbAGPR bound to the cofactor NADP(+) have been solved and analyzed. Each MtbAGPR subunit consists of alpha/beta and alpha+beta domains; NADP(+) is bound in the cleft between them. The hydrogen bonds and hydrophobic contacts between the enzyme and cofactor have been examined. Comparison of the apo and the bound enzyme structures has revealed a conformational change in MtbAGPR upon NADP(+) binding. Namely, a loop (Leu88 to His92) moves more than 5 A to confine sterically the cofactor's adenine moiety in a hydrophobic pocket. To identify the catalytically important residues in MtbAGPR, a docking of the substrate to the enzyme has been performed using the present structure of the MtbAGPR/NADP(+) complex. It reveals that residues His217 and His219 could form hydrogen bonds with the docked substrate. In addition, an ion pair could form between the substrate phosphate group and the guanidinium group of Arg114. These interactions optimally place and orient the substrate for subsequent nucleophilic attack by Cys158 on the substrate gamma-carboxyl group. His219 is the most probable general base to accept a proton from Cys158 and an adjacent ion pair interaction with the side-chain carboxyl group of Glu222 could help to stabilize the resulting positive charge on His219. For this catalytic triad to function efficiently it requires a small conformational change of the order of 1 A in the loop containing His217 and His219; this could easily result from the substrate binding.


  • Organizational Affiliation

    Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
N-acetyl-gamma-glutamyl-phosphate reductase
A, B
352Mycobacterium tuberculosis H37RvMutation(s): 0 
Gene Names: argC
EC: 1.2.1.38
UniProt
Find proteins for P9WPZ9 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WPZ9 
Go to UniProtKB:  P9WPZ9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP9WPZ9
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.163 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 141.456α = 90
b = 78.214β = 127.46
c = 88.034γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2006-09-05
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Source and taxonomy, Version format compliance
  • Version 1.3: 2023-08-30
    Changes: Data collection, Database references, Derived calculations, Refinement description