Structural characterization of filaments formed by human Xrcc4-Cernunnos/XLF complex involved in nonhomologous DNA end-joining.

ABSTRACT: Cernunnos/XLF is a core protein of the nonhomologous DNA end-joining (NHEJ) pathway that processes the majority of DNA double-strand breaks in mammals. Cernunnos stimulates the final ligation step catalyzed by the complex between DNA ligase IV and Xrcc4 (X4). Here we present the crystal structure of the X4(1-157)-Cernunnos(1-224) complex at 5.5-Å resolution and identify the relative positions of the two factors and their binding sites. The X-ray structure reveals a filament arrangement for X4(1-157) and Cernunnos(1-224) homodimers mediated by repeated interactions through their N-terminal head domains. A filament arrangement of the X4-Cernunnos complex was confirmed by transmission electron microscopy analyses both with truncated and full-length proteins. We further modeled the interface a

SUBMITTER: Ropars V 

PROVIDER: S-EPMC3150875 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature