Structural and substrate-binding studies of pantothenate synthenate (PS)provide insights into homotropic inhibition by pantoate in PS's

Experimental Data Snapshot

  • Resolution: 1.67 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.191 

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X-ray crystallographic and NMR studies of pantothenate synthetase provide insights into the mechanism of homotropic inhibition by pantoate

Chakrabarti, K.S.Thakur, K.G.Gopal, B.Sarma, S.P.

(2010) FEBS J 277: 697-712

  • DOI: https://doi.org/10.1111/j.1742-4658.2009.07515.x
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The structural basis for the homotropic inhibition of pantothenate synthetase by the substrate pantoate was investigated by X-ray crystallography and high-resolution NMR spectroscopic methods. The tertiary structure of the dimeric N-terminal domain of Escherichia coli pantothenate synthetase, determined by X-ray crystallography to a resolution of 1.7 A, showed a second molecule of pantoate bound in the ATP-binding pocket. Pantoate binding to the ATP-binding site induced large changes in structure, mainly for backbone and side chain atoms of residues in the ATP binding HXGH(34-37) motif. Sequence-specific NMR resonance assignments and solution secondary structure of the dimeric N-terminal domain, obtained using samples enriched in (2)H, (13)C, and (15)N, indicated that the secondary structural elements were conserved in solution. Nitrogen-15 edited two-dimensional solution NMR chemical shift mapping experiments revealed that pantoate, at 10 mm, bound at these two independent sites. The solution NMR studies unambiguously demonstrated that ATP stoichiometrically displaced pantoate from the ATP-binding site. All NMR and X-ray studies were conducted at substrate concentrations used for enzymatic characterization of pantothenate synthetase from different sources [Jonczyk R & Genschel U (2006) J Biol Chem 281, 37435-37446]. As pantoate binding to its canonical site is structurally conserved, these results demonstrate that the observed homotropic effects of pantoate on pantothenate biosynthesis are caused by competitive binding of this substrate to the ATP-binding site. The results presented here have implications for the design and development of potential antibacterial and herbicidal agents.

  • Organizational Affiliation

    Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Pantothenate synthetase
A, B
176Escherichia coli K-12Mutation(s): 1 
Gene Names: panC
Find proteins for P31663 (Escherichia coli (strain K12))
Explore P31663 
Go to UniProtKB:  P31663
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP31663
Sequence Annotations
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
PAF PDBBind:  3GUZ Kd: 4.20e+4 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 1.67 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.191 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.89α = 90
b = 77.5β = 90
c = 78.85γ = 90
Software Package:
Software NamePurpose
MAR345dtbdata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-02-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2021-11-10
    Changes: Database references, Derived calculations
  • Version 1.3: 2024-05-29
    Changes: Data collection