Delineation of the Xrcc4-interacting region in the globular head domain of cernunnos/XLF.
In mammals, the majority of DNA double-strand breaks are processed by the nonhomologous end-joining (NHEJ) pathway, composed of seven factors: Ku70, Ku80, DNA-PKcs, Artemis, Xrcc4 (X4), DNA-ligase IV (L4), and Cernunnos/XLF. Cernunnos is part of the ligation complex, constituted by X4 and L4. To improve our knowledge on the structure and function of Cernunnos, we performed a systematic mutagenesis study on positions selected from an analysis of the recent three-dimensional structures of this factor. Ten of 27 screened mutants were nonfunctional in several DNA repair assays. Outside amino acids critical for the expression and stability of Cernunnos, we identified three amino acids (Arg(64), Leu(65), and Leu(115)) essential for the interaction with X4 and the proper function of Cernunnos. Docking the crystal structures of the two factors further validated this probable interaction surface of Cernunnos with X4.
Malivert
Laurent
L
INSERM, Hôpital Necker-Enfants Malades U768, Unité de Développement Normal et Pathologique du Système Immunitaire, Paris, France.
Ropars
Virginie
V
Nunez
Marcela
M
Drevet
Pascal
P
Miron
Simona
S
Faure
Guilhem
G
Guerois
Raphael
R
Mornon
Jean-Paul
JP
Revy
Patrick
P
Charbonnier
Jean-Baptiste
JB
Callebaut
Isabelle
I
de Villartay
Jean-Pierre
JP
D000596:Amino Acids; D001665:Binding Sites; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D017434:Protein Structure, Tertiary
D000596:Amino Acids; D004268:DNA-Binding Proteins; C508551:NHEJ1 protein, human; C101467:XRCC4 protein, human; D045643:DNA Repair Enzymes