5HF7

TDG enzyme-substrate complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.54 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.187 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural basis of damage recognition by thymine DNA glycosylase: Key roles for N-terminal residues.

Coey, C.T.Malik, S.S.Pidugu, L.S.Varney, K.M.Pozharski, E.Drohat, A.C.

(2016) Nucleic Acids Res 44: 10248-10258

  • DOI: 10.1093/nar/gkw768
  • Primary Citation of Related Structures:  
    5JXY, 5HF7, 5FF8

  • PubMed Abstract: 
  • Thymine DNA Glycosylase (TDG) is a base excision repair enzyme functioning in DNA repair and epigenetic regulation. TDG removes thymine from mutagenic G·T mispairs arising from deamination of 5-methylcytosine (mC), and it processes other deamination-derived lesions including uracil (U) ...

    Thymine DNA Glycosylase (TDG) is a base excision repair enzyme functioning in DNA repair and epigenetic regulation. TDG removes thymine from mutagenic G·T mispairs arising from deamination of 5-methylcytosine (mC), and it processes other deamination-derived lesions including uracil (U). Essential for DNA demethylation, TDG excises 5-formylcytosine and 5-carboxylcytosine, derivatives of mC generated by Tet (ten-eleven translocation) enzymes. Here, we report structural and functional studies of TDG 82-308 , a new construct containing 29 more N-terminal residues than TDG 111-308 , the construct used for previous structures of DNA-bound TDG. Crystal structures and NMR experiments demonstrate that most of these N-terminal residues are disordered, for substrate- or product-bound TDG 82-308 Nevertheless, G·T substrate affinity and glycosylase activity of TDG 82-308 greatly exceeds that of TDG 111-308 and is equivalent to full-length TDG. We report the first high-resolution structures of TDG in an enzyme-substrate complex, for G·U bound to TDG 82-308 (1.54 Å) and TDG 111-308 (1.71 Å), revealing new enzyme-substrate contacts, direct and water-mediated. We also report a structure of the TDG 82-308 product complex (1.70 Å). TDG 82-308 forms unique enzyme-DNA interactions, supporting its value for structure-function studies. The results advance understanding of how TDG recognizes and removes modified bases from DNA, particularly those resulting from deamination.


    Organizational Affiliation

    University of Maryland Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD 21201, USA.



Macromolecules

Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
G/T mismatch-specific thymine DNA glycosylaseA227Homo sapiensMutation(s): 0 
Gene Names: TDG
EC: 3.2.2.29
UniProt & NIH Common Fund Data Resources
Find proteins for Q13569 (Homo sapiens)
Explore Q13569 
Go to UniProtKB:  Q13569
PHAROS:  Q13569
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsLengthOrganismImage
DNA (28-MER)B [auth C]28unidentified
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsLengthOrganismImage
DNA (28-MER)C [auth D]28unidentified
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.54 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.187 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 97.03α = 90
b = 52.75β = 95.18
c = 81.34γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
XDSdata reduction
Aimlessdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM072711

Revision History  (Full details and data files)

  • Version 1.0: 2016-09-28
    Type: Initial release
  • Version 1.1: 2016-12-14
    Changes: Database references
  • Version 1.2: 2017-09-20
    Changes: Author supporting evidence
  • Version 1.3: 2019-12-25
    Changes: Author supporting evidence