Identification of the polypyrimidine tract binding protein-associated splicing factor.p54(nrb) complex as a candidate DNA double-strand break rejoining factor.
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Bladen CL, Udayakumar D, Takeda Y, Dynan WS
Identification of the polypyrimidine tract binding protein-associated splicing factor.p54(nrb) complex as a candidate DNA double-strand break rejoining factor.
J Biol Chem. 2005 Feb 18;280(7):5205-10. Epub 2004 Dec 7.
- PubMed ID
- 15590677 [ View in PubMed]
- Abstract
The biological effects of ionizing radiation are attributable, in large part, to induction of DNA double-strand breaks. We report here the identification of a new protein factor that reconstitutes efficient double-strand break rejoining when it is added to a reaction containing the five other polypeptides known to participate in the human nonhomologous end-joining pathway. The factor is a stable heteromeric complex of polypyrimidine tract-binding protein-associated splicing factor (PSF) and a 54-kDa nuclear RNA-binding protein (p54(nrb)). These polypeptides, to which a variety of functions have previously been attributed, share extensive homology, including tandem RNA recognition motif domains. The PSF.p54(nrb) complex cooperates with Ku protein to form a functional preligation complex with substrate DNA. Based on structural comparison with related proteins, we propose a model where the four RNA recognition motif domains in the heteromeric PSF.p54(nrb) complex cooperate to align separate DNA molecules.