3HCC

Crystal Structure of hPNMT in Complex With anti-9-amino-5-(trifluromethyl) benzonorbornene and AdoHcy


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Molecular recognition of physiological substrate noradrenaline by the adrenaline-synthesizing enzyme PNMT and factors influencing its methyltransferase activity.

Drinkwater, N.Gee, C.L.Puri, M.Criscione, K.R.McLeish, M.J.Grunewald, G.L.Martin, J.L.

(2009) Biochem.J. 422: 463-471

  • DOI: 10.1042/BJ20090702
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Substrate specificity is critically important for enzyme catalysis. In the adrenaline-synthesizing enzyme PNMT (phenylethanolamine N-methyltransferase), minor changes in substituents can convert substrates into inhibitors. Here we report the crystal ...

    Substrate specificity is critically important for enzyme catalysis. In the adrenaline-synthesizing enzyme PNMT (phenylethanolamine N-methyltransferase), minor changes in substituents can convert substrates into inhibitors. Here we report the crystal structures of six human PNMT complexes, including the first structure of the enzyme in complex with its physiological ligand R-noradrenaline. Determining this structure required rapid soak methods because of the tendency for noradrenaline to oxidize. Comparison of the PNMT-noradrenaline complex with the previously determined PNMT-p-octopamine complex demonstrates that these two substrates form almost equivalent interactions with the enzyme and show that p-octopamine is a valid model substrate for PNMT. The crystal structures illustrate the adaptability of the PNMT substrate binding site in accepting multi-fused ring systems, such as substituted norbornene, as well as noradrenochrome, the oxidation product of noradrenaline. These results explain why only a subset of ligands recognized by PNMT are methylated by the enzyme; bulky substituents dictate the binding orientation of the ligand and can thereby place the acceptor amine too far from the donor methyl group for methylation to occur. We also show how the critical Glu(185) catalytic residue can be replaced by aspartic acid with a loss of only 10-fold in catalytic efficiency. This is because protein backbone movements place the Asp(185) carboxylate almost coincident with the carboxylate of Glu(185). Conversely, replacement of Glu(185) by glutamine reduces catalytic efficiency almost 300-fold, not only because of the loss of charge, but also because the variant residue does not adopt the same conformation as Glu(185).


    Organizational Affiliation

    Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, The University of Queensland, Brisbane, Queensland 4072, Australia.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phenylethanolamine N-methyltransferase
A, B
289Homo sapiensMutation(s): 0 
Gene Names: PNMT (PENT)
EC: 2.1.1.28
Find proteins for P11086 (Homo sapiens)
Go to Gene View: PNMT
Go to UniProtKB:  P11086
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAH
Query on SAH

Download SDF File 
Download CCD File 
A, B
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N
 Ligand Interaction
LT3
Query on LT3

Download SDF File 
Download CCD File 
A, B
(1S,4R,9S)-5-(trifluoromethyl)-1,2,3,4-tetrahydro-1,4-methanonaphthalen-9-amine
C12 H12 F3 N
HHIJEPNAHYLKPE-RNSXUZJQSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
LT3Ki: 10000 - 16000 nM (100) BINDINGDB
LT3Ki: 13000 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.205 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 94.720α = 90.00
b = 94.720β = 90.00
c = 186.210γ = 90.00
Software Package:
Software NamePurpose
d*TREKdata reduction
PHENIXrefinement
d*TREKdata scaling
CrystalCleardata collection
CNSphasing
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-08-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance