6GO4

TdT chimera (Loop1 of pol mu) - binary complex with ddCTP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.96 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.203 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural evidence for an intransbase selection mechanism involving Loop1 in polymerase mu at an NHEJ double-strand break junction.

Loc'h, J.Gerodimos, C.A.Rosario, S.Tekpinar, M.Lieber, M.R.Delarue, M.

(2019) J Biol Chem 294: 10579-10595

  • DOI: 10.1074/jbc.RA119.008739
  • Primary Citation of Related Structures:  
    6GO7, 6GO6, 6GO3, 6GO5, 6GO4

  • PubMed Abstract: 
  • Eukaryotic DNA polymerase (Pol) X family members such as Pol μ and terminal deoxynucleotidyl transferase (TdT) are important components for the nonhomologous DNA end-joining (NHEJ) pathway. TdT participates in a specialized version of NHEJ, V(D)J recombination ...

    Eukaryotic DNA polymerase (Pol) X family members such as Pol μ and terminal deoxynucleotidyl transferase (TdT) are important components for the nonhomologous DNA end-joining (NHEJ) pathway. TdT participates in a specialized version of NHEJ, V(D)J recombination. It has primarily nontemplated polymerase activity but can take instructions across strands from the downstream dsDNA, and both activities are highly dependent on a structural element called Loop1. However, it is unclear whether Pol μ follows the same mechanism, because the structure of its Loop1 is disordered in available structures. Here, we used a chimeric TdT harboring Loop1 of Pol μ that recapitulated the functional properties of Pol μ in ligation experiments. We solved three crystal structures of this TdT chimera bound to several DNA substrates at 1.96-2.55 Å resolutions, including a full DNA double-strand break (DSB) synapsis. We then modeled the full Pol μ sequence in the context of one these complexes. The atomic structure of an NHEJ junction with a Pol X construct that mimics Pol μ in a reconstituted system explained the distinctive properties of Pol μ compared with TdT. The structure suggested a mechanism of base selection relying on Loop1 and taking instructions via the in trans templating base independently of the primer strand. We conclude that our atomic-level structural observations represent a paradigm shift for the mechanism of base selection in the Pol X family of DNA polymerases.


    Organizational Affiliation

    From the Unité de Dynamique Structurale des Macromolécules, Institut Pasteur, UMR 3528 du CNRS, 25 Rue du Dr. Roux, 75015 Paris, France and marc.delarue@pasteur.fr.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DNA nucleotidylexotransferase,DNA-directed DNA/RNA polymerase mu,DNA nucleotidylexotransferaseA401Mus musculusMutation(s): 0 
Gene Names: DnttTdtPolmpolmu
EC: 2.7.7.31 (PDB Primary Data), 2.7.7.7 (PDB Primary Data), 3.1.11 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for P09838 (Mus musculus)
Explore P09838 
Go to UniProtKB:  P09838
IMPC:  MGI:98659
Find proteins for Q9JIW4 (Mus musculus)
Explore Q9JIW4 
Go to UniProtKB:  Q9JIW4
IMPC:  MGI:1860191
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DCT
Query on DCT

Download Ideal Coordinates CCD File 
D [auth A]2',3'-DIDEOXYCYTIDINE 5'-TRIPHOSPHATE
C9 H16 N3 O12 P3
ARLKCWCREKRROD-POYBYMJQSA-N
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
C [auth A]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
NA
Query on NA

Download Ideal Coordinates CCD File 
B [auth A]SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.96 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.203 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.97α = 90
b = 85.62β = 90
c = 114.91γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
XDSdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
FranceFondation ARC pour la recherche sur le cancer

Revision History  (Full details and data files)

  • Version 1.0: 2019-06-05
    Type: Initial release
  • Version 1.1: 2019-12-25
    Changes: Database references