1HQ2

CRYSTAL STRUCTURE OF A TERNARY COMPLEX OF E.COLI HPPK(R82A) WITH MGAMPCPP AND 6-HYDROXYMETHYL-7,8-DIHYDROPTERIN AT 1.25 ANGSTROM RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.25 Å
  • R-Value Free: 0.132 
  • R-Value Work: 0.107 
  • R-Value Observed: 0.097 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Dynamic Roles of Arginine Residues 82 and 92 of Escherichia coli 6-Hydroxymethyl-7,8-dihydropterin Pyrophosphokinase: Crystallographic Studies

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

(2003) Biochemistry 42: 1573-1580

  • DOI: 10.1021/bi0267994
  • Primary Citation of Related Structures:  
    3IP0, 1G4C, 1F9H, 1HQ2, 1IM6, 1KBR

  • PubMed Abstract: 
  • 6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin (HP), the first reaction in the folate biosynthetic pathway. Arginine residues 82 and 92, strictly conserve ...

    6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin (HP), the first reaction in the folate biosynthetic pathway. Arginine residues 82 and 92, strictly conserved in 35 HPPK sequences, play dynamic roles in the catalytic cycle of the enzyme. At 0.89-A resolution, two distinct conformations are observed for each of the two residues in the crystal structure of the wild-type HPPK in complex with two HP variants, two Mg(2+) ions, and an ATP analogue. Structural information suggests that R92 first binds to the alpha-phosphate group of ATP and then shifts to interact with the beta-phosphate as R82, which initially does not bind to ATP, moves in and binds to alpha-phosphate when the pyrophosphoryl transfer is about to occur. The dynamic roles of R82 and R92 are further elucidated by five more crystal structures of two mutant proteins, R82A and R92A, with and without bound ligands. Two oxidized forms of HP are observed with an occupancy ratio of 0.50:0.50 in the 0.89-A structure. The oxidation of HP has significant impact on its binding to the protein as well as the conformation of nearby residue W89.


    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
    • Catalytic Center Assembly of HPPK as Revealed by the Crystal Structure of a Ternary Complex at 1.25 A Resolution
      Blaszczyk, J., Shi, G., Yan, H., Ji, X.
      (2000) Structure 8: 1049

    Organizational Affiliation

    Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, Maryland 21702, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
6-HYDROXYMETHYL-7,8-DIHYDROPTERIN PYROPHOSPHOKINASEA158Escherichia coliMutation(s): 1 
EC: 2.7.6.3
Find proteins for P26281 (Escherichia coli (strain K12))
Explore P26281 
Go to UniProtKB:  P26281
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
APC
Query on APC

Download CCD File 
A
DIPHOSPHOMETHYLPHOSPHONIC ACID ADENOSYL ESTER
C11 H18 N5 O12 P3
CAWZRIXWFRFUQB-IOSLPCCCSA-N
 Ligand Interaction
PH2
Query on PH2

Download CCD File 
A
2-AMINO-6-HYDROXYMETHYL-7,8-DIHYDRO-3H-PTERIDIN-4-ONE
C7 H9 N5 O2
CQQNNQTXUGLUEV-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download CCD File 
A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
MG
Query on MG

Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.25 Å
  • R-Value Free: 0.132 
  • R-Value Work: 0.107 
  • R-Value Observed: 0.097 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 73.372α = 90
b = 37.843β = 117.18
c = 58.018γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
SHELXL-97refinement

Structure Validation

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Entry History 

Deposition Data

  • Deposited Date: 2000-12-13 
  • Released Date: 2003-04-15 
  • Deposition Author(s): Blaszczyk, J., Ji, X.

Revision History 

  • Version 1.0: 2003-04-15
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance