BLM helicase suppresses recombination at G-quadruplex motifs in transcribed genes

• DOI: 10.1038/s41467-017-02760-1
• Publication Date: 2018-01-12T10:41:03Z
• Authors: Niek van Wietmars...; Sarra Merzouk; Nancy Halsema; Diana C. J. Spier...; Victor Guryev; Peter M. Lansdorp
• Keywords: Bloom syndrome; Sister chromatid exchange; RecQ helicase

Bloom syndrome is a cancer predisposition disorder caused by mutations in the BLM helicase gene. Cells from persons with exhibit striking genomic instability characterized excessive sister chromatid exchange events (SCEs). We applied single-cell DNA template strand sequencing (Strand-seq) to map locations of SCEs. Our results show that absence BLM, SCEs human and murine cells do not occur randomly throughout genome but are strikingly enriched at coding regions, specifically sites guanine quadruplex (G4) motifs transcribed genes. propose protects against suppressing recombination G4 structures, particularly regions genome.