1Y98

Structure of the BRCT repeats of BRCA1 bound to a CtIP phosphopeptide.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.234 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Basis for Cell Cycle Checkpoint Control by the BRCA1-CtIP Complex.

Varma, A.K.Brown, R.S.Birrane, G.Ladias, J.A.A.

(2005) Biochemistry 44: 10941-10946

  • DOI: 10.1021/bi0509651

  • PubMed Abstract: 
  • The breast and ovarian tumor suppressor BRCA1 has important functions in cell cycle checkpoint control and DNA repair. Two tandem BRCA1 C-terminal (BRCT) domains are essential for the tumor suppression activity of BRCA1 and interact in a phosphorylat ...

    The breast and ovarian tumor suppressor BRCA1 has important functions in cell cycle checkpoint control and DNA repair. Two tandem BRCA1 C-terminal (BRCT) domains are essential for the tumor suppression activity of BRCA1 and interact in a phosphorylation-dependent manner with proteins involved in DNA damage-induced checkpoint control, including the DNA helicase BACH1 and the CtBP-interacting protein (CtIP). The crystal structure of the BRCA1 BRCT repeats bound to the PTRVSpSPVFGAT phosphopeptide corresponding to residues 322-333 of human CtIP was determined at 2.5 A resolution. The peptide binds to a cleft formed by the interface of the two BRCTs in a two-pronged manner, with phospho-Ser327 and Phe330 anchoring the peptide through extensive contacts with BRCA1 residues. Several hydrogen bonds and salt bridges that stabilize the BRCA1-BACH1 complex are missing in the BRCA1-CtIP interaction, offering a structural basis for the approximately 5-fold lower affinity of BRCA1 for CtIP compared to that of BACH1, as determined by isothermal titration calorimetry. Importantly, the side chain of Arg1775 in the cancer-associated BRCA1 mutation M1775R sterically clashes with the phenyl ring of CtIP Phe330, disrupting the BRCA1-CtIP interaction. These results provide new insights into the molecular mechanisms underlying the dynamic selection of target proteins involved in DNA repair and cell cycle control by BRCA1 and reveal how certain cancer-associated mutations affect these interactions.


    Organizational Affiliation

    Molecular Medicine Laboratory and Macromolecular Crystallography Unit, Division of Experimental Medicine, Harvard Institutes of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Breast cancer type 1 susceptibility protein
A
214Homo sapiensMutation(s): 0 
Gene Names: BRCA1 (RNF53)
EC: 2.3.2.27
Find proteins for P38398 (Homo sapiens)
Go to Gene View: BRCA1
Go to UniProtKB:  P38398
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
CtIP PHOSPHORYLATED PEPTIDE
B
12N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CO
Query on CO

Download SDF File 
Download CCD File 
A
COBALT (II) ION
Co
XLJKHNWPARRRJB-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
B
L-PEPTIDE LINKINGC3 H8 N O6 PSER
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.234 
  • Space Group: P 61 2 2
Unit Cell:
Length (Å)Angle (°)
a = 113.118α = 90.00
b = 113.118β = 90.00
c = 121.876γ = 120.00
Software Package:
Software NamePurpose
PHASERphasing
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-08-30
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance