4PAR

The 5-Hydroxymethylcytosine-Specific Restriction Enzyme AbaSI in a Complex with Product-like DNA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.89 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structure of 5-hydroxymethylcytosine-specific restriction enzyme, AbaSI, in complex with DNA.

Horton, J.R.Borgaro, J.G.Griggs, R.M.Quimby, A.Guan, S.Zhang, X.Wilson, G.G.Zheng, Y.Zhu, Z.Cheng, X.

(2014) Nucleic Acids Res 42: 7947-7959

  • DOI: 10.1093/nar/gku497
  • Primary Citation of Related Structures:  
    4PBA, 4PBB, 4PAR

  • PubMed Abstract: 
  • AbaSI, a member of the PvuRts1I-family of modification-dependent restriction endonucleases, cleaves deoxyribonucleic acid (DNA) containing 5-hydroxymethylctosine (5hmC) and glucosylated 5hmC (g5hmC), but not DNA containing unmodified cytosine. AbaSI has been used as a tool for mapping the genomic locations of 5hmC, an important epigenetic modification in the DNA of higher organisms ...

    AbaSI, a member of the PvuRts1I-family of modification-dependent restriction endonucleases, cleaves deoxyribonucleic acid (DNA) containing 5-hydroxymethylctosine (5hmC) and glucosylated 5hmC (g5hmC), but not DNA containing unmodified cytosine. AbaSI has been used as a tool for mapping the genomic locations of 5hmC, an important epigenetic modification in the DNA of higher organisms. Here we report the crystal structures of AbaSI in the presence and absence of DNA. These structures provide considerable, although incomplete, insight into how this enzyme acts. AbaSI appears to be mainly a homodimer in solution, but interacts with DNA in our structures as a homotetramer. Each AbaSI subunit comprises an N-terminal, Vsr-like, cleavage domain containing a single catalytic site, and a C-terminal, SRA-like, 5hmC-binding domain. Two N-terminal helices mediate most of the homodimer interface. Dimerization brings together the two catalytic sites required for double-strand cleavage, and separates the 5hmC binding-domains by ∼70 Å, consistent with the known activity of AbaSI which cleaves DNA optimally between symmetrically modified cytosines ∼22 bp apart. The eukaryotic SET and RING-associated (SRA) domains bind to DNA containing 5-methylcytosine (5mC) in the hemi-methylated CpG sequence. They make contacts in both the major and minor DNA grooves, and flip the modified cytosine out of the helix into a conserved binding pocket. In contrast, the SRA-like domain of AbaSI, which has no sequence specificity, contacts only the minor DNA groove, and in our current structures the 5hmC remains intra-helical. A conserved, binding pocket is nevertheless present in this domain, suitable for accommodating 5hmC and g5hmC. We consider it likely, therefore, that base-flipping is part of the recognition and cleavage mechanism of AbaSI, but that our structures represent an earlier, pre-flipped stage, prior to actual recognition.


    Related Citations: 
    • High-resolution enzymatic mapping of genomic 5-hydroxymethylcytosine in mouse embryonic stem cells.
      Sun, Z., Terragni, J., Jolyon, T., Borgaro, J.G., Liu, Y., Yu, L., Guan, S., Wang, H., Sun, D., Cheng, X., Zhu, Z., Pradhan, S., Zheng, Y.
      (2013) Cell Rep 3: 567
    • Characterization of the 5-hydroxymethylcytosine-specific DNA restriction endonucleases.
      Borgaro, J.G., Zhu, Z.
      (2013) Nucleic Acids Res 41: 4198
    • Comparative characterization of the PvuRts1I family of restriction enzymes and their application in mapping genomic 5-hydroxymethylcytosine.
      Wang, H., Guan, S., Quimby, A., Cohen-Karni, D., Pradhan, S., Wilson, G., Roberts, R.J., Zhu, Z., Zheng, Y.
      (2011) Nucleic Acids Res 39: 9294

    Organizational Affiliation

    Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA xcheng@emory.edu.



Macromolecules

Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Uncharacterized protein AbaSIF [auth A], E [auth B], G [auth C], H [auth D]321Acinetobacter baumannii SDFMutation(s): 3 
Gene Names: ABSDF3356
Find proteins for B0VN39 (Acinetobacter baumannii (strain SDF))
Explore B0VN39 
Go to UniProtKB:  B0VN39
Protein Feature View
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  • Reference Sequence
  • Find similar nucleic acids by:  Sequence   |   Structure
  • Entity ID: 1
    MoleculeChainsLengthOrganismImage
    DNA 18-MERA [auth E], C [auth F]18Tequatrovirus
    • Find similar nucleic acids by:  Sequence   |   Structure
    • Entity ID: 2
      MoleculeChainsLengthOrganismImage
      DNA 14-MERB [auth G], D [auth H]14Tequatrovirus
      Small Molecules
      Ligands 1 Unique
      IDChainsName / Formula / InChI Key2D Diagram3D Interactions
      EDO
      Query on EDO

      Download Ideal Coordinates CCD File 
      I [auth C]1,2-ETHANEDIOL
      C2 H6 O2
      LYCAIKOWRPUZTN-UHFFFAOYSA-N
       Ligand Interaction
      Experimental Data & Validation

      Experimental Data

      • Method: X-RAY DIFFRACTION
      • Resolution: 2.89 Å
      • R-Value Free: 0.249 
      • R-Value Work: 0.190 
      • R-Value Observed: 0.193 
      • Space Group: P 1 21 1
      Unit Cell:
      Length ( Å )Angle ( ˚ )
      a = 54.826α = 90
      b = 144.704β = 94.57
      c = 105.033γ = 90
      Software Package:
      Software NamePurpose
      PHENIXrefinement

      Structure Validation

      View Full Validation Report



      Entry History & Funding Information

      Deposition Data


      Funding OrganizationLocationGrant Number
      National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM049245-20

      Revision History  (Full details and data files)

      • Version 1.0: 2014-06-25
        Type: Initial release
      • Version 1.1: 2014-08-06
        Changes: Database references
      • Version 1.2: 2014-10-01
        Changes: Database references
      • Version 1.3: 2017-09-20
        Changes: Author supporting evidence, Database references, Derived calculations, Other, Source and taxonomy, Structure summary
      • Version 1.4: 2019-12-25
        Changes: Author supporting evidence