5OMD image
Entry Detail
PDB ID:
5OMD
Keywords:
Title:
Crystal structure of S. cerevisiae Ddc2 N-terminal coiled-coil domain
Biological Source:
PDB Version:
Deposition Date:
2017-07-28
Release Date:
2017-10-25
Method Details:
Experimental Method:
Resolution:
2.10 Å
R-Value Free:
0.26
R-Value Work:
0.22
R-Value Observed:
0.23
Space Group:
P 2 2 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:DNA damage checkpoint protein LCD1
Chain IDs:A
Chain Length:66
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
Primary Citation
Structural Basis of Mec1-Ddc2-RPA Assembly and Activation on Single-Stranded DNA at Sites of Damage.
Mol. Cell 68 431 445.e5 (2017)
PMID: 29033322 DOI: 10.1016/j.molcel.2017.09.019

Abstact

Mec1-Ddc2 (ATR-ATRIP) is a key DNA-damage-sensing kinase that is recruited through the single-stranded (ss) DNA-binding replication protein A (RPA) to initiate the DNA damage checkpoint response. Activation of ATR-ATRIP in the absence of DNA damage is lethal. Therefore, it is important that damage-specific recruitment precedes kinase activation, which is achieved at least in part by Mec1-Ddc2 homodimerization. Here, we report a structural, biochemical, and functional characterization of the yeast Mec1-Ddc2-RPA assembly. High-resolution co-crystal structures of Ddc2-Rfa1 and Ddc2-Rfa1-t11 (K45E mutant) N termini and of the Ddc2 coiled-coil domain (CCD) provide insight into Mec1-Ddc2 homodimerization and damage-site targeting. Based on our structural and functional findings, we present a Mec1-Ddc2-RPA-ssDNA composite structural model. By way of validation, we show that RPA-dependent recruitment of Mec1-Ddc2 is crucial for maintaining its homodimeric state at ssDNA and that Ddc2's recruitment domain and CCD are important for Mec1-dependent survival of UV-light-induced DNA damage.

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