1XVA

METHYLTRANSFERASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of glycine N-methyltransferase from rat liver.

Fu, Z.Hu, Y.Konishi, K.Takata, Y.Ogawa, H.Gomi, T.Fujioka, M.Takusagawa, F.

(1996) Biochemistry 35: 11985-11993

  • DOI: 10.1021/bi961068n

  • PubMed Abstract: 
  • Glycine N-methyltransferase (GNMT) from rat liver is a tetrameric enzyme with 292 amino acid residues in each identical subunit and catalyzes the S-adenosylmethionine (AdoMet) dependent methylation of glycine to form sarcosine. The crystal structure ...

    Glycine N-methyltransferase (GNMT) from rat liver is a tetrameric enzyme with 292 amino acid residues in each identical subunit and catalyzes the S-adenosylmethionine (AdoMet) dependent methylation of glycine to form sarcosine. The crystal structure of GNMT complexed with AdoMet and acetate, a competitive inhibitor of glycine, has been determined at 2.2 A resolution. The subunit of GNMT forms a spherical shape with an extended N-terminal region which corks the entrance of active site of the adjacent subunit. The active site is located in the near center of the spherical subunit. As a result, the AdoMet and acetate in the active site are completely surrounded by amino acid residues. Careful examination of the structure reveals several characteristics of GNMT. (1) Although the structure of the AdoMet binding domain of the GNMT is very similar to those of other methyltransferases recently determined by X-ray diffraction method, an additional domain found only in GNMT encloses the active site to form a molecular basket, and consequently the structure of GNMT looks quite different from those of other methyltransferases. (2) This unique molecular structure can explain why GNMT can capture folate and polycyclic aromatic hydrocarbons. (3) The unique N-terminal conformation and the subunit structure can explain why GNMT exhibits positive cooperativity in binding AdoMet. From the structural features of GNMT, we propose that the enzyme might be able to capture yet unidentified molecules in the cytosol and thus participates in various biological processes including detoxification of polycyclic aromatic hydrocarbons. In the active site, acetate binds near the S-CH3 moiety of AdoMet. Simple modeling indicates that the amino group of the substrate glycine can be placed close to the methyl group of AdoMet within 3.0 A and form a hydrogen bond with the carboxyl group of Glu15 of the adjacent subunit. On the basis of the ternary complex structure, the mechanism of the methyl transfer in GNMT has been proposed.


    Organizational Affiliation

    Department of Biochemistry, University of Kansas, Lawrence 66045, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GLYCINE N-METHYLTRANSFERASE
A, B
292Rattus norvegicusMutation(s): 0 
Gene Names: Gnmt
EC: 2.1.1.20
Find proteins for P13255 (Rattus norvegicus)
Go to UniProtKB:  P13255
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

Download SDF File 
Download CCD File 
A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
SAM
Query on SAM

Download SDF File 
Download CCD File 
A, B
S-ADENOSYLMETHIONINE
C15 H22 N6 O5 S
MEFKEPWMEQBLKI-FCKMPRQPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.196 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 86.400α = 90.00
b = 175.700β = 90.00
c = 45.500γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORphasing
KUAVSTdata reduction
KUMDSdata reduction
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-01-27
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance