1O9T

Methionine adenosyltransferase complexed with both substrates ATP and methionine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.288 
  • R-Value Work: 0.265 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structures of Methionine Adenosyltransferase Complexed with Substrates and Products Reveal the Methionine-ATP Recognition and Give Insights Into the Catalytic Mechanism

Gonzalez, B.Pajares, M.A.Hermoso, J.A.Guillerm, D.Guillerm, G.Sanz-Aparicio, J.

(2003) J.Mol.Biol. 331: 407

  • Primary Citation of Related Structures:  1O90, 1O92, 1O93

  • PubMed Abstract: 
  • Methionine adenosyltransferases (MATs) are a family of enzymes in charge of synthesising S-adenosylmethionine (SAM), the most important methyl donor present in living organisms. These enzymes use methionine and ATP as reaction substrates, which react ...

    Methionine adenosyltransferases (MATs) are a family of enzymes in charge of synthesising S-adenosylmethionine (SAM), the most important methyl donor present in living organisms. These enzymes use methionine and ATP as reaction substrates, which react in a S(N)2 fashion where the sulphur atom from methionine attacks C5' from ATP while triphosphate chain is cleaved. A MAT liver specific isoenzyme has been detected, which exists in two distinct oligomeric forms, a dimer (MAT III) and a tetramer (MAT I). Our previously reported crystal structure of MAT I complexed with an inhibitor led to the identification of the methionine-binding site. We present here the results obtained from the complex of MAT I with a competitive inhibitor of methionine, (2S,4S)-amino-4,5-epoxypentanoic acid (AEP), which presents the same features at the methionine binding site reported before. We have also analysed several complexes of this enzyme with methionine and ATP and analogues of them, in order to characterise the interaction that is produced between both substrates. The crystal structures of the complexes reveal how the substrates recognise each other at the active site of the enzyme, and suggest a putative binding site for the product SAM. The residues involved in the interactions of substrates and products with MAT have been identified, and the results agree with all the previous data concerning mutagenesis experiments and crystallographic work. Moreover, all the information provided from the analysis of the complexes has allowed us to postulate a catalytic mechanism for this family of enzymes. In particular, we propose a key role for Lys182 in the correct positioning of the substrates, and Asp135(*), in stabilising the sulphonium group formed in the product (SAM).


    Related Citations: 
    • The Crystal Structure of Tetrameric Methionine Adenosyltransferase Fom Rat Liver Reveals the Methionine Binding Site
      Gonzalez, B.,Pajares, M.A.,Hermoso, J.A.,Alvarez, L.,Garrido, F.,Sufrin, J.R.,Sanz-Aparicio, J.
      (2000) J.Mol.Biol. 300: 363


    Organizational Affiliation

    Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física "Rocasolano", CSIC, Serrano 119, 28006 Madrid, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
S-ADENOSYLMETHIONINE SYNTHETASE
A, B
396Rattus norvegicusGene Names: Mat1a (Ams1)
EC: 2.5.1.6
Find proteins for P13444 (Rattus norvegicus)
Go to UniProtKB:  P13444
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

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A, B
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
ATP
Query on ATP

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B
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
PO4
Query on PO4

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A, B
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
MG
Query on MG

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A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
MET
Query on MET

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A
METHIONINE
C5 H11 N O2 S
FFEARJCKVFRZRR-BYPYZUCNSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.288 
  • R-Value Work: 0.265 
  • Space Group: P 41 2 2
Unit Cell:
Length (Å)Angle (°)
a = 114.990α = 90.00
b = 114.990β = 90.00
c = 160.340γ = 90.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
X-PLORphasing
SCALAdata scaling
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-08-07
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance