Building a Structural Understanding of DNA Damage Repair a Mass Shift Analysis of DNA Ligase IV Regulation

摘要

The mass-shift analysis of scaffolding protein XRCC4 and of the BRCT domain of DNA Ligase IV showed a global stabilization of the stalk of XRCC4 while in complex with BRCT. Furthermore, the C-terminal region (CTR) of XRCC4 may be involved in the stabilization of the BRCT domains in the complex. The phosphorylation of the CTR regulates XRCC4 interactions with other proteins and DNA and could be involved in the regulation of this interaction. Analysis of XRCC4-XLF interactions confirmed the interaction seen in the X-ray structure. Moreover this experiment showed a modification of the stalk regions of both proteins which become less floppy in the complex. Additionally, the binding of short double stranded DNA to XRCC4-XLF complex seems to promote assembly of the complex.