Fig. 4.
Role of UBZ domain in hPolη function in vivo. (A) Sequence alignment of human (Hs) and yeast (Sc) Polη UBZ domains. Highly conserved residues are shown in bold. The positions of 2 short β-sheets and the α-helix as determined from the solution structure of hPolη UBZ are indicated above the sequences. (B) Complementation of the UV sensitivity of XPV cells by hPolη UBZ mutations. The survival of XPV cells transfected with WT or UBZ mutant Polη constructs was examined after exposure to 5 J/m2 of UV irradiation followed by incubation on growth media in the presence of 1 mM caffeine.