3HCC

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

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.208 

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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:  
    3HCF, 3HCA, 3HCB, 3HCC, 3HCD, 3HCE

  • 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: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Phenylethanolamine N-methyltransferaseA, B289Homo sapiensMutation(s): 0 
Gene Names: PNMT, PENT
EC: 2.1.1.28
Find proteins for P11086 (Homo sapiens)
Explore P11086 
Go to UniProtKB:  P11086
NIH Common Fund Data Resources
PHAROS  P11086
GTEx  ENSG00000141744
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAH
Query on SAH
Download CCD File 
A, B
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N		 Ligand Interaction
LT3
Query on LT3
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:  16000   nM  BindingDB
SAHKi:  62300   nM  BindingDB
SAHKi:  29000   nM  BindingDB
LT3Ki:  13000   nM  BindingDB
LT3Ki:  14000   nM  BindingDB
LT3Ki:  13000   nM  Binding MOAD
LT3Ki:  13000   nM  BindingDB
LT3Ki:  10000   nM  BindingDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.208 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 94.72α = 90
b = 94.72β = 90
c = 186.21γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
CrystalCleardata collection
d*TREKdata reduction
d*TREKdata scaling
CNSphasing

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

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