1RR6

Structure of human purine nucleoside phosphorylase in complex with Immucillin-H and phosphate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.243 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Plasmodium falciparum purine nucleoside phosphorylase: crystal structures, immucillin inhibitors, and dual catalytic function.

Shi, W.Ting, L.M.Kicska, G.A.Lewandowicz, A.Tyler, P.C.Evans, G.B.Furneaux, R.H.Kim, K.Almo, S.C.Schramm, V.L.

(2004) J.Biol.Chem. 279: 18103-18106

  • DOI: 10.1074/jbc.C400068200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Purine nucleoside phosphorylase from Plasmodium falciparum (PfPNP) is an anti-malarial target based on the activity of Immucillins. The crystal structure of PfPNP.Immucillin-H (ImmH).SO(4) reveals a homohexamer with ImmH and SO(4) bound at each catal ...

    Purine nucleoside phosphorylase from Plasmodium falciparum (PfPNP) is an anti-malarial target based on the activity of Immucillins. The crystal structure of PfPNP.Immucillin-H (ImmH).SO(4) reveals a homohexamer with ImmH and SO(4) bound at each catalytic site. A solvent-filled cavity close to the 5'-hydroxyl group of ImmH suggested that PfPNP can accept additional functional groups at the 5'-carbon. Assays established 5'-methylthioinosine (MTI) as a substrate for PfPNP. MTI is not found in human metabolism. These properties of PfPNP suggest unusual purine pathways in P. falciparum and provide structural and mechanistic foundations for the design of malaria-specific transition state analogue inhibitors. 5'-Methylthio-Immucillin-H (MT-ImmH) was designed to resemble the transition state of PfPNP and binds to PfPNP and human-PNP with K(d) values of 2.7 and 303 nm, respectively, to give a discrimination factor of 112. MT-ImmH is the first inhibitor that favors PfPNP inhibition. The structure of PfPNP.MT-ImmH.SO(4) shows that the hydrophobic methylthio group inserts into a hydrophobic region adjacent to the more hydrophilic 5'-hydroxyl binding site of ImmH. The catalytic features of PfPNP indicate a dual cellular function in purine salvage and polyamine metabolism. Combined metabolic functions in a single enzyme strengthen the rationale for targeting PfPNP in anti-malarial action.


    Organizational Affiliation

    Department of Biochemistry, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Purine nucleoside phosphorylase
A
289Homo sapiensMutation(s): 0 
Gene Names: PNP (NP)
EC: 2.4.2.1
Find proteins for P00491 (Homo sapiens)
Go to Gene View: PNP
Go to UniProtKB:  P00491
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
A
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
IMH
Query on IMH

Download SDF File 
Download CCD File 
A
1,4-DIDEOXY-4-AZA-1-(S)-(9-DEAZAHYPOXANTHIN-9-YL)-D-RIBITOL
C11 H14 N4 O4
IWKXDMQDITUYRK-KUBHLMPHSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
IMHKd: 0.056 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.243 
  • Space Group: H 3 2
Unit Cell:
Length (Å)Angle (°)
a = 142.351α = 90.00
b = 142.351β = 90.00
c = 167.665γ = 120.00
Software Package:
Software NamePurpose
CNSphasing
SCALEPACKdata scaling
AMoREphasing
CNSrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-02-22
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance