DNA-Binding Deficiency of Trp690 and Phe733 Mutants
(A) Pull-down assays were performed by coincubating Sf9 cell lysate (5 μl) containing wild-type XPC or the indicated Ala mutants and single-stranded DNA beads. The binding buffer contained 0.3 M NaCl. The fractions of free (F) and bound (B) protein were separated and analyzed by gel electrophoresis and immunobloting using specific monoclonal antibodies. The panel on the right shows the quantitative evaluation of three independent binding assays (± SD).
(B) Side-by-side comparison of the DNA-binding capacity of wild-type XPC protein (lanes 7 and 8) and the indicated mutants (lanes 1–6).