PDBsum entry: 2ing

DNA binding protein

PDB id: 2ing

Contents

Protein chain

208 a.a. *

Ligands

SO4 ×2

Metals

_CO

* Residue conservation analysis

PDB id:

2ing

Name:

DNA binding protein

Title:

X-ray structure of the brca1 brct mutant m1775k

Structure:

Breast cancer type 1 susceptibility protein. Chain: x. Fragment: brct1, brct2. Synonym: ring finger protein 53. Engineered: yes. Mutation: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: brca1, rnf53. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

Resolution:

3.60Å R-factor: 0.251 R-free: 0.302

Authors:

G.Birrane,A.Soni,J.A.A.Ladias

Key ref:

M.Tischkowitz et al. (2008). Pathogenicity of the BRCA1 missense variant M1775K is determined by the disruption of the BRCT phosphopeptide-binding pocket: a multi-modal approach. Eur J Hum Genet, 16, 820-832. PubMed id: 18285836 DOI: 10.1038/ejhg.2008.13

Date:

07-Oct-06 Release date: 04-Sep-07

Protein chain

P38398  (BRCA1_HUMAN) -  Breast cancer type 1 susceptibility protein

Seq: 1863 a.a.

Struc: 208 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 

• Cellular component: intracellular (2 terms)
• Biological process: DNA repair (1 term)
• Biochemical function: DNA binding (2 terms)

DOI no: 10.1038/ejhg.2008.13

Eur J Hum Genet 16:820-832 (2008)

PubMed id: 18285836

Pathogenicity of the BRCA1 missense variant M1775K is determined by the disruption of the BRCT phosphopeptide-binding pocket: a multi-modal approach.

M.Tischkowitz, N.Hamel, M.A.Carvalho, G.Birrane, A.Soni, E.H.van Beers, S.A.Joosse, N.Wong, D.Novak, L.A.Quenneville, S.A.Grist, P.M.Nederlof, D.E.Goldgar, S.V.Tavtigian, A.N.Monteiro, J.A.Ladias, W.D.Foulkes.

ABSTRACT

A number of germ-line mutations in the BRCA1 gene confer susceptibility to breast and ovarian cancer. However, it remains difficult to determine whether many single amino-acid (missense) changes in the BRCA1 protein that are frequently detected in the clinical setting are pathologic or not. Here, we used a combination of functional, crystallographic, biophysical, molecular and evolutionary techniques, and classical genetic segregation analysis to demonstrate that the BRCA1 missense variant M1775K is pathogenic. Functional assays in yeast and mammalian cells showed that the BRCA1 BRCT domains carrying the amino-acid change M1775K displayed markedly reduced transcriptional activity, indicating that this variant represents a deleterious mutation. Importantly, the M1775K mutation disrupted the phosphopeptide-binding pocket of the BRCA1 BRCT domains, thereby inhibiting the BRCA1 interaction with the proteins BRIP1 and CtIP, which are involved in DNA damage-induced checkpoint control. These results indicate that the integrity of the BRCT phosphopeptide-binding pocket is critical for the tumor suppression function of BRCA1. Moreover, this study demonstrates that multiple lines of evidence obtained from a combination of functional, structural, molecular and evolutionary techniques, and classical genetic segregation analysis are required to confirm the pathogenicity of rare variants of disease-susceptibility genes and obtain important insights into the underlying pathogenetic mechanisms.