2C7O

HhaI DNA methyltransferase complex with 13mer oligonucleotide containing 2-aminopurine adjacent to the target base (PCGC:GMGC) and SAH


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Time-Resolved Fluorescence of 2-Aminopurine as a Probe of Base Flipping in M.HhaI-DNA Complexes.

Neely, R.K.Daujotyte, D.Grazulis, S.Magennis, S.W.Dryden, D.T.F.Klimasauskas, S.Jones, A.C.

(2005) Nucleic Acids Res 33: 6953

  • DOI: 10.1093/nar/gki995
  • Primary Citation of Related Structures:  
    2C7R, 2C7Q, 2C7P, 2C7O

  • PubMed Abstract: 
  • DNA base flipping is an important mechanism in molecular enzymology, but its study is limited by the lack of an accessible and reliable diagnostic technique. A series of crystalline complexes of a DNA methyltransferase, M.HhaI, and its cognate DNA, in which a fluorescent nucleobase analogue, 2-aminopurine (AP), occupies defined positions with respect the target flipped base, have been prepared and their structures determined at higher than 2 A resolution ...

    DNA base flipping is an important mechanism in molecular enzymology, but its study is limited by the lack of an accessible and reliable diagnostic technique. A series of crystalline complexes of a DNA methyltransferase, M.HhaI, and its cognate DNA, in which a fluorescent nucleobase analogue, 2-aminopurine (AP), occupies defined positions with respect the target flipped base, have been prepared and their structures determined at higher than 2 A resolution. From time-resolved fluorescence measurements of these single crystals, we have established that the fluorescence decay function of AP shows a pronounced, characteristic response to base flipping: the loss of the very short (approximately 100 ps) decay component and the large increase in the amplitude of the long (approximately 10 ns) component. When AP is positioned at sites other than the target site, this response is not seen. Most significantly, we have shown that the same clear response is apparent when M.HhaI complexes with DNA in solution, giving an unambiguous signal of base flipping. Analysis of the AP fluorescence decay function reveals conformational heterogeneity in the DNA-enzyme complexes that cannot be discerned from the present X-ray structures.


    Organizational Affiliation

    School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK.



Macromolecules

Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MODIFICATION METHYLASE HHAIA327Haemophilus haemolyticusMutation(s): 0 
EC: 2.1.1.37
Find proteins for P05102 (Haemophilus parahaemolyticus)
Explore P05102 
Go to UniProtKB:  P05102
Protein Feature View
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  • Reference Sequence
  • Find similar nucleic acids by:  Sequence   |   Structure
  • Entity ID: 2
    MoleculeChainsLengthOrganismImage
    5'-D(*T*GP*GP*AP*TP*GP*(5CM)*GP*CP*TP*GP*AP *C)-3'C13synthetic construct
    • Find similar nucleic acids by:  Sequence   |   Structure
    • Entity ID: 3
      MoleculeChainsLengthOrganismImage
      5'-D(*T*GP*TP*CP*AP*(2PR)*CP*GP*CP*AP*TP*CP *C)-3'D13synthetic construct
      Small Molecules
      Ligands 2 Unique
      IDChainsName / Formula / InChI Key2D Diagram3D Interactions
      SAH
      Query on SAH

      Download CCD File 
      A
      S-ADENOSYL-L-HOMOCYSTEINE
      C14 H20 N6 O5 S
      ZJUKTBDSGOFHSH-WFMPWKQPSA-N
       Ligand Interaction
      SO4
      Query on SO4

      Download CCD File 
      A
      SULFATE ION
      O4 S
      QAOWNCQODCNURD-UHFFFAOYSA-L
       Ligand Interaction
      Experimental Data & Validation

      Experimental Data

      • Method: X-RAY DIFFRACTION
      • Resolution: 1.90 Å
      • R-Value Free: 0.215 
      • R-Value Work: 0.194 
      • R-Value Observed: 0.194 
      • Space Group: H 3 2
      Unit Cell:
      Length ( Å )Angle ( ˚ )
      a = 95.18α = 90
      b = 95.18β = 90
      c = 312.547γ = 120
      Software Package:
      Software NamePurpose
      CNSrefinement
      DENZOdata reduction
      SCALEPACKdata scaling
      AMoREphasing

      Structure Validation

      View Full Validation Report



      Entry History 

      Deposition Data

      Revision History 

      • Version 1.0: 2005-12-14
        Type: Initial release
      • Version 1.1: 2014-01-29
        Changes: Atomic model, Derived calculations, Non-polymer description, Other, Refinement description, Source and taxonomy, Structure summary, Version format compliance
      • Version 1.2: 2019-07-24
        Changes: Data collection, Derived calculations