| Literature DB >> 11675489 |
Abstract
We have identified a human nuclease that specifically cleaves four-stranded DNA stabilized by G quartets (G4 DNA). This nuclease, GQN1 (G quartet nuclease 1), cuts within the single-stranded region 5' of the barrel formed by stacked G quartets. GQN1 does not cleave duplex or single-stranded DNA, Holliday junctions, or G4 RNA. Cleavage depends on DNA structure and not on flanking sequence. Activity is elevated in but not restricted to B cells, making GQN1 a strong candidate for function in immunoglobulin heavy chain class switch recombination. Identification of a mammalian nuclease that specifically cleaves G4 DNA provides further support for the notion that DNA structures stabilized by G quartets form in vivo and function in regulated recombination and genomic evolution.Entities:
Mesh:
Substances:
Year: 2001 PMID: 11675489 PMCID: PMC60073 DOI: 10.1073/pnas.231479198
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205