3ROD

Methyltransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.72 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.208 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural basis of substrate recognition in human nicotinamide N-methyltransferase.

Peng, Y.Sartini, D.Pozzi, V.Wilk, D.Emanuelli, M.Yee, V.C.

(2011) Biochemistry 50: 7800-7808

  • DOI: 10.1021/bi2007614
  • Primary Citation of Related Structures:  
    3ROD

  • PubMed Abstract: 
  • Nicotinamide N-methyltransferase (NNMT) catalyzes the N-methylation of nicotinamide, pyridines, and other analogues using S-adenosyl-l-methionine as donor. NNMT plays a significant role in the regulation of metabolic pathways and is expressed at markedly high levels in several kinds of cancers, presenting it as a potential molecular target for cancer therapy ...

    Nicotinamide N-methyltransferase (NNMT) catalyzes the N-methylation of nicotinamide, pyridines, and other analogues using S-adenosyl-l-methionine as donor. NNMT plays a significant role in the regulation of metabolic pathways and is expressed at markedly high levels in several kinds of cancers, presenting it as a potential molecular target for cancer therapy. We have determined the crystal structure of human NNMT as a ternary complex bound to both the demethylated donor S-adenosyl-l-homocysteine and the acceptor substrate nicotinamide, to 2.7 Å resolution. These studies reveal the structural basis for nicotinamide binding and highlight several residues in the active site which may play roles in nicotinamide recognition and NNMT catalysis. The functional importance of these residues was probed by mutagenesis. Of three residues near the nicotinamide's amide group, substitution of S201 and S213 had no effect on enzyme activity while replacement of D197 dramatically decreased activity. Substitutions of Y20, whose side chain hydroxyl interacts with both the nicotinamide aromatic ring and AdoHcy carboxylate, also compromised activity. Enzyme kinetics analysis revealed k(cat)/K(m) decreases of 2-3 orders of magnitude for the D197A and Y20A mutants, confirming the functional importance of these active site residues. The mutants exhibited substantially increased K(m) for both NCA and AdoMet and modestly decreased k(cat). MD simulations revealed long-range conformational effects which provide an explanation for the large increase in K(m)(AdoMet) for the D197A mutant, which interacts directly only with nicotinamide in the ternary complex crystal structure.


    Organizational Affiliation

    Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Nicotinamide N-methyltransferaseA, B, C, D283Homo sapiensMutation(s): 3 
Gene Names: NNMT
EC: 2.1.1.1
Find proteins for P40261 (Homo sapiens)
Explore P40261 
Go to UniProtKB:  P40261
NIH Common Fund Data Resources
PHAROS:  P40261
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.72 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.208 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.663α = 106.57
b = 61.793β = 103.98
c = 74.342γ = 104.14
Software Package:
Software NamePurpose
MOLREPphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2011-04-25 
  • Released Date: 2011-09-07 
  • Deposition Author(s): Peng, Y., Yee, V.C.

Revision History  (Full details and data files)

  • Version 1.0: 2011-09-07
    Type: Initial release
  • Version 1.1: 2011-09-21
    Changes: Database references