1EX8

CRYSTAL STRUCTURE OF 6-HYDROXYMETHYL-7,8-DIHYDROPTERIN PYROPHOSPHOKINASE COMPLEXED WITH HP4A, THE TWO-SUBSTRATE-MIMICKING INHIBITOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.185 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Bisubstrate analogue inhibitors of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: synthesis and biochemical and crystallographic studies.

Shi, G.Blaszczyk, J.Ji, X.Yan, H.

(2001) J Med Chem 44: 1364-1371

  • DOI: 10.1021/jm0004493
  • Primary Citation of Related Structures:  
    1EX8

  • PubMed Abstract: 
  • 6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the transfer of pyrophosphate from ATP to 6-hydroxymethyl-7,8-dihydropterin (HP), leading to the biosynthesis of folate cofactors. Like other enzymes in the folate pathway, HPPK is an ideal target for the development of antimicrobial agents because the enzyme is essential for microorganisms but is absent from human and animals ...

    6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the transfer of pyrophosphate from ATP to 6-hydroxymethyl-7,8-dihydropterin (HP), leading to the biosynthesis of folate cofactors. Like other enzymes in the folate pathway, HPPK is an ideal target for the development of antimicrobial agents because the enzyme is essential for microorganisms but is absent from human and animals. Three bisubstrate analogues have been synthesized for HPPK and characterized by biochemical and X-ray crystallographic analyses. All three bisubstrate analogues consist of a pterin, an adenosine moiety, and a link composed of 2-4 phosphoryl groups. P(1)-(6-Hydroxymethylpterin)-P(2)-(5'-adenosyl)diphosphate (HP(2)A, 5) shows little affinity and inhibitory activity for E. coli HPPK. P(1)-(6-Hydroxymethylpterin)-P(3)-(5'-adenosyl)triphosphate (HP(3)A, 6) shows moderate affinity and inhibitory activity with K(d) = 4.25 microM in the presence of Mg(2+) and IC(50) = 1.27 microM. P(1)-(6-Hydroxymethylpterin)-P(4)-(5'-adenosyl)tetraphosphate (HP(4)A, 7) shows the highest affinity and inhibitory activity with K(d) = 0.47 microM in the presence of Mg(2+) and IC(50) = 0.44 microM. The affinity of MgHP(4)A for HPPK is approximately 116 and 76 times higher than that of MgADP and 6-hydroxymethylpterin, respectively. The crystal structure of HPPK in complex with 7 (HPPK.MgHP(4)A) has been determined at 1.85 A resolution with a crystallographic R factor of 0.185. The crystal structure shows that 7 occupies both HP- and ATP-binding sites and induces significant conformational changes in HPPK. The biochemical and structural studies of the bisubstrate analogues indicate that the bisubstrate analogue approach can produce more potent inhibitors for HPPK and the minimum length of the link for a bisubstrate analogue is approximately 7 A.


    Related Citations: 
    • Crystal Structure of 6-hydroxymethyl-7,8-dihydropterin Pyrophosphokinase, a Potential Target for the Development of Novel Antimicrobial Agents
      Xiao, B., Shi, G., Chen, X., Yan, H., Ji, X.
      (1999) Structure 7: 489

    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
6-HYDROXYMETHYL-7,8-DIHYDROPTERIN PYROPHOSPHOKINASEA158Escherichia coliMutation(s): 0 
EC: 2.7.6.3
Find proteins for P26281 (Escherichia coli (strain K12))
Explore P26281 
Go to UniProtKB:  P26281
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
A4P
Query on A4P

Download Ideal Coordinates CCD File 
D [auth A]6-(ADENOSINE TETRAPHOSPHATE-METHYL)-7,8-DIHYDROPTERIN
C17 H24 N10 O17 P4
ZKRKFZJAQKKHKL-SUGPNEFASA-N
 Ligand Interaction
CL
Query on CL

Download Ideal Coordinates CCD File 
C [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
B [auth A]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
A4PKd :  470   nM  PDBBind
A4PKd:  470   nM  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.185 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 38.053α = 90
b = 61.857β = 90
c = 67.106γ = 90
Software Package:
Software NamePurpose
AMoREphasing
SHELXL-97refinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2000-05-01 
  • Released Date: 2001-05-01 
  • Deposition Author(s): Blaszczyk, J., Ji, X.

Revision History  (Full details and data files)

  • Version 1.0: 2001-05-01
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance