FIGURE 4.

Telomeric DNA binding activity of Cdc13(451–693)p is required for ternary complex formation. A, purification of His₆-tagged Cdc13(451–693)^R635Cp. Two μg of the purified protein were analyzed by 10% SDS-PAGE and stained with Coomassie Blue. B, Cdc13(451–693)^R635Cp fails to form complex with Yku-DNA. Around 2 ng of ³²P-labeled T₃T₄ DNA substrate were incubated with Yku and/or Cdc13(451–693) ^R635Cp and analyzed by EMSA. The amounts of Yku used in lanes 2–5 and 14–17 were 50, 150, 450, and 1350 nm, respectively. Lanes 10–13 each has 1350 nm Yku. The amounts of Cdc13(451–693)^R635Cp were the same as those for Fig. 2B. An autoradiogram is shown here.