Experimental Data Snapshot

  • Resolution: 2.60 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.214 

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Differential binding of S-adenosylmethionine S-adenosylhomocysteine and Sinefungin to the adenine-specific DNA methyltransferase M.TaqI.

Schluckebier, G.Kozak, M.Bleimling, N.Weinhold, E.Saenger, W.

(1997) J Mol Biol 265: 56-67

  • DOI: https://doi.org/10.1006/jmbi.1996.0711
  • Primary Citation of Related Structures:  
    1AQI, 1AQJ, 2ADM

  • PubMed Abstract: 

    The crystal structures of the binary complexes of the DNA methyltransferase M.TaqI with the inhibitor Sinefungin and the reaction product S-adenosyl-L-homocysteine were determined, both at 2.6 A resolution. Structural comparison of these binary complexes with the complex formed by M.TaqI and the cofactor S-adenosyl-L-methionine suggests that the key element for molecular recognition of these ligands is the binding of their adenosine part in a pocket, and discrimination between cofactor, reaction product and inhibitor is mediated by different conformations of these molecules; the methionine part of S-adenosyl-L-methionine is located in the binding cleft, whereas the amino acid moieties of Sinefungin and S-adenosyl-L-homocysteine are in a different orientation and interact with the active site amino acid residues 105NPPY108. Dissociation constants for the complexes of M.TaqI with the three ligands were determined spectrofluorometrically. Sinefungin binds more strongly than S-adenosyl-L-homocysteine or S-adenosyl-L-methionine, with KD=0.34 microM, 2.4 microM and 2.0 microM, respectively.

  • Organizational Affiliation

    Institut für Kristallographie Freie Universität Berlin, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
421Thermus aquaticusMutation(s): 0 
Gene Names: TAQ
Find proteins for P14385 (Thermus aquaticus)
Explore P14385 
Go to UniProtKB:  P14385
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP14385
Sequence Annotations
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
SAM PDBBind:  2ADM Kd: 2000 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.60 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.214 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 130.66α = 90
b = 141.83β = 90
c = 53.15γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
DENZOdata reduction

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-01-27
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-02-14
    Changes: Data collection, Database references, Derived calculations, Other