The protein DCLRE1A (DNA cross-link repair 1A) is also referred to as SNM1A (sensitive to nitrogen mustard 1A). DCLRE1A is a 5’ to 3’ exonuclease that forms a complex with the Cockayne syndrome B (CSB) protein. In this complex, CSB modulates the exonuclease activity of DCLRE1A and coordinates the efficient assembly of DCLRE1A to sites of DNA damage.[8] In human cells, this complex is recruited to DNA inter-strand cross-links, a form of DNA damage. The complex then participates in the repair of the cross-linked DNA. DCLRE1A protein is thought to be recruited by CSB to facilitate cross-link unhooking following incision 5’ to the cross-link by another complex, the ERCC1/XPF nuclease complex.[8] Failure of the DCLRE1A/CSB complex to carry out its repair function may contribute to the degenerative pathologies and premature aging features of Cockayne syndrome.
