What characteristic of dna makes nucleotide excision repair (ner) mechanisms possible?

Sometimes, DNA damages because of the chemicals , radiations and mutagens.Nucleotide excision repair is a DNA repair mechanism. There are three possible pathways to repair the DNA damage. 

1) Nuclear excision repair
2)Base excision repair
3)DNA mismatch repair

the above given characteristics of the DNA makes nucleotide excision repair mechanism possible.