3TD8

Structural Analysis of Pneumocystis carinii Dihydrofolate Reductase Complex with NADPH and 2,4-diamino-5-methyl-6-[2'-(4-carboxy-1-pentynyl)-5'-methoxybenzyl]pyrido[2,3-d]pyrimidine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural analysis of Pneumocystis cariniidihydrofolate reductase complexed with NADPH and 2,4-diamino-6-[2-(5-carboxypent-1-yn-1-yl)-5-methoxybenzyl]-5-methylpyrido[2,3-d]pyrimidine.

Cody, V.Pace, J.Stewart, E.

(2012) Acta Crystallogr.,Sect.F 68: 418-423

  • DOI: 10.1107/S1744309112008688

  • PubMed Abstract: 
  • Structural data are reported for 2,4-diamino-6-[2-(5-carboxypent-1-yn-1-yl)-5-methoxybenzyl]-5-methylpyrido[2,3-d]pyrimidine (PY1014) complexed with Pneumocystis carinii dihydrofolate reductase (pcDHFR) refined to 1.8 Å resolution. These data reveal ...

    Structural data are reported for 2,4-diamino-6-[2-(5-carboxypent-1-yn-1-yl)-5-methoxybenzyl]-5-methylpyrido[2,3-d]pyrimidine (PY1014) complexed with Pneumocystis carinii dihydrofolate reductase (pcDHFR) refined to 1.8 Å resolution. These data reveal that the carboxylate of the ω-carboxyalkynyl side chain of PY1014, the most pcDHFR-selective analog in this series, forms ionic interactions with the conserved Arg75 in the substrate-binding pocket of pcDHFR. The reversal of the 2',5'-substitution pattern of this analog compared with the highly selective diaminopyrimidine analog PY1011 (i.e. the 5'-pentynylcarboxy-5'-methoxy pattern of PY1014 versus the 3',4'-dimethoxy-5'-pentynylcarboxy pattern of PY1011) is necessary to achieve optimal interaction with Arg75 as observed in other structures. The larger diaminopyrido[2,3-d]pyrimidine ring of PY1014 places the 5'-methoxy group closer to Leu25 and Ser64 than does the diaminopyrimidine ring of PY1011. The 5'-methoxy O atom forms a hydrogen bond to the amide of Leu25 (O···N, 2.7 Å) and the 5'-methoxy methyl group makes a hydrophobic contact of 3.1 Å with C(β) of Ser64. Although the IC(50) values of PY1014 and PY1011 are similar, inhibition data show that the selectivity of PY1011 for pcDHFR is significantly greater. The greater selectivity for pcDHFR compared with mammalian DHFR of these inhibitors is also influenced by the enhanced hydrophobic interactions of the side-chain methylene atoms with Phe69 of pcDHFR compared with Asn64 of mammalian DHFR.


    Organizational Affiliation

    Structural Biology Department, Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA. cody@hwi.buffalo.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Dihydrofolate reductase
A
206Pneumocystis cariniiMutation(s): 0 
EC: 1.5.1.3
Find proteins for P16184 (Pneumocystis carinii)
Go to UniProtKB:  P16184
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
D2R
Query on D2R

Download SDF File 
Download CCD File 
A
6-{2-[(2,4-diamino-5-methylpyrido[2,3-d]pyrimidin-6-yl)methyl]-4-methoxyphenyl}hex-5-ynoic acid
2,4-Diamino--5-methyl-6-[2'-(4-carboxy-1-pentynyl)-5'-methoxybenzyl]pyrido[2,3-d]pyrimidine
C22 H23 N5 O3
MAWHZPJVFGJFTF-UHFFFAOYSA-N
 Ligand Interaction
NDP
Query on NDP

Download SDF File 
Download CCD File 
A
NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H30 N7 O17 P3
ACFIXJIJDZMPPO-NNYOXOHSSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
D2RIC50: 1.2 nM (100) BINDINGDB
D2RIC50: 1.2 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.197 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 36.123α = 90.00
b = 42.630β = 95.20
c = 59.894γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
SCALAdata scaling
DENZOdata reduction
REFMACrefinement
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-04-11
    Type: Initial release
  • Version 1.1: 2012-05-02
    Type: Database references