Crystallization and preliminary X-ray diffraction analysis of the human XRCC4-XLF complex.

Abstract

XRCC4 and XLF are key proteins in the repair of DNA double-strand breaks through nonhomologous end-joining. Together, they form a complex that stimulates the ligation of double-strand breaks. Owing to the suggested filamentous nature of this complex, structural studies via X-ray crystallography have proven difficult. Multiple truncations of the XLF and XRCC4 proteins were cocrystallized, but yielded low-resolution diffraction (~20 Å). However, a combination of microseeding, dehydration and heavy metals improved the diffraction of XRCC4(Δ157)-XLF(Δ224) crystals to 3.9 Å resolution. Although molecular replacement alone was unable to produce a solution, when combined with the anomalous signal from tantalum bromide clusters initial phasing was successfully obtained.

• Authors: Sara N Andres, Murray S Junop
• Journal: Acta crystallographica. Section F, Structural biology and crystallization communications (Acta Crystallogr Sect F Struct Biol Cryst Commun) Vol. 67 Issue Pt 11 Pg. 1399-402 (Nov 01 2011) ISSN: 1744-3091 [Electronic] England
• PMID: 22102241 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2011 International Union of Crystallography. All rights reserved.

Chemical References

• DNA-Binding Proteins
• NHEJ1 protein, human
• XRCC4 protein, human
• DNA Repair Enzymes

Topics

• Crystallization
• Crystallography, X-Ray
• DNA Repair Enzymes (chemistry, metabolism)
• DNA-Binding Proteins (chemistry, metabolism)
• Humans
• Protein Binding