DNA repair in a yeast origin of replication: contributions of photolyase and nucleotide excision repair.
DNA damage formation and repair are tightly linked to protein-DNA interactions in chromatin. We have used minichromosomes in yeast as chromatin substrates in vivo to investigate how nucleotide excision repair (NER) and repair by DNA-photolyase (photoreactivation) remove pyrimidine dimers from an origin of replication ( ARS1 ). The ARS1 region is nuclease sensitive and flanked by nucleosomes on both sides. Photoreactivation was generally faster than NER at all sites. Site-specific heterogeneity of repair was observed for both pathways. This heterogeneity was different for NER and photoreactivation and it was altered in a minichromosome where ARS1 was transcribed. The results indicate distinct inter-actions of the repair systems with protein complexes bound in the ARS region (ORC, Abf1) and a predominant role of photolyase in CPD repair of an origin of replication.
Suter
B
B
Institut für Zellbiologie, ETH-Zürich, Hönggerberg, CH-8093 Zürich, Switzerland.
Wellinger
R E
RE
Thoma
F
F
D004249:DNA Damage; D004260:DNA Repair; D004271:DNA, Fungal / Q000235:genetics* / Q000528:radiation effects; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000378:metabolism*; D007700:Kinetics; D011740:Pyrimidine Dimers / Q000378:metabolism; D018741:Replication Origin; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000528:radiation effects; D014466:Ultraviolet Rays
D004271:DNA, Fungal; D011740:Pyrimidine Dimers; D004255:Deoxyribodipyrimidine Photo-Lyase