ABSTRACT
This chapter is focused on repair of UV lesions in nucleosomes by photolyase and nucleotide excision repair (NER). Eukaryotic genomes are folded by histone proteins into an array of nucleosomes, which is further condensed into chromatin fibers and higher order structures. Nucleosomes perform complex roles in DNA function. As they present the DNA in two supercoils on the outside, they modulate the accessibility of DNA and they are obstacles for proteins that translocate along the DNA. On the other hand, nucleosomes are dynamic and undergo various structural transitions that affect the accessibility of DNA and can be induced or suppressed by chromatin remodeling activities or by polymerases moving along the DNA during transcription and replication.
