 |
PDBsum entry 3pc6
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
DNA binding protein
|
PDB id
|
|
|
|
3pc6
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
The structural basis for partitioning of the xrcc1/DNA ligase III-α Brct-Mediated dimer complexes.
|
|
|
Authors
|
|
M.J.Cuneo,
S.A.Gabel,
J.M.Krahn,
M.A.Ricker,
R.E.London.
|
|
|
Ref.
|
|
Nucleic Acids Res, 2011,
39,
7816-7827.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The ultimate step common to almost all DNA repair pathways is the ligation of
the nicked intermediate to form contiguous double-stranded DNA. In the mammalian
nucleotide and base excision repair pathways, the ligation step is carried out
by ligase III-α. For efficient ligation, ligase III-α is constitutively bound
to the scaffolding protein XRCC1 through interactions between the C-terminal
BRCT domains of each protein. Although structural data for the individual
domains has been available, no structure of the complex has been determined and
several alternative proposals for this interaction have been advanced.
Interpretation of the models is complicated by the formation of homodimers that,
depending on the model, may either contribute to, or compete with heterodimer
formation. We report here the structures of both homodimer complexes as well as
the heterodimer complex. Structural characterization of the heterodimer formed
from a longer XRCC1 BRCT domain construct, including residues comprising the
interdomain linker region, revealed an expanded heterodimer interface with the
ligase III-α BRCT domain. This enhanced linker-mediated binding interface plays
a significant role in the determination of heterodimer/homodimer selectivity.
These data provide fundamental insights into the structural basis of
BRCT-mediated dimerization, and resolve questions related to the organization of
this important repair complex.
|
|
|
|
|
|
|
