I provide a personal account of the discovery, cloning and functional analyses of the human
XPG gene. Mutations in this gene can give rise to the group G form of xeroderma
pigmentosum (XP) and, in some cases, to severe early onset Cockayne syndrome (CS). The
XPG protein has well established catalytic and structural roles in nucleotide excision repair
(NER) and it acts as a cofactor for a DNA glycosylase that removes oxidised pyrimidines
from DNA. XPG may also be involved in transcription-coupled repair of this kind of damage …