Fig. 4. L200* eliminates the DNA-binding domain of XPA.

a Sanger sequencing of germline DNA confirms the L200* pDGV in XPA. b The cryo-EM structure of the XPA-TFIIH complex showing the interaction between XPA and DNA during nucleotide excision repair²³. The L200* pDGV (red arrow) eliminates the entire alpha-helix of the DNA binding domain (dotted line). c The L200* pDGV (red arrow) eliminates the positively charged amino acid residues (red) which bind to the negatively charged DNA backbone. These positively charged amino acid residues (arrows), such as R207, are commonly affected by germline mutations in xeroderma pigmentosum patients.