Repair of an interstrand DNA cross-link initiated by ERCC1-XPF repair/recombination nuclease.
Interstrand DNA cross-link damage is a severe challenge to genomic integrity. Nucleotide excision repair plays some role in the repair of DNA cross-links caused by psoralens and other agents. However, in mammalian cells there is evidence that the ERCC1-XPF nuclease has a specialized additional function during interstrand DNA cross-link repair, beyond its role in nucleotide excision repair. We placed a psoralen monoadduct or interstrand cross-link in a duplex, 4-6 bases from a junction with unpaired DNA. ERCC1-XPF endonucleolytically cleaved within the duplex on either side of the adduct, on the strand having an unpaired 3' tail. Cross-links that were cleaved only on the 5' side were purified and reincubated with ERCC1-XPF. A second cleavage was then observed on the 3' side. Relevant partially unwound structures near a cross-link may be expected to arise frequently, for example at stalled DNA replication forks. The results show that the single enzyme ERCC1-XPF can release one arm of a cross-link and suggest a novel mechanism for interstrand cross-link repair.
Kuraoka
I
I
Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, United Kingdom.
Kobertz
W R
WR
Ariza
R R
RR
Biggerstaff
M
M
Essigmann
J M
JM
Wood
R D
RD
D001483:Base Sequence; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004720:Endonucleases; D005363:Ficusin / Q000494:pharmacology; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*
D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D009841:Oligonucleotides; D011506:Proteins; C095888:xeroderma pigmentosum group F protein; C071447:ERCC1 protein, human; D004720:Endonucleases; D005363:Ficusin