Figure 3.

Characterization of Pp POT1 Interaction with Telomeric DNA in Vitro.

(A) EMSA was performed with a cocktail of seven ³²P-labeled oligonucleotides corresponding to two (2TELO) (lanes 1 to 3) or three (3TELO) (lanes 4 and 5) TTTAGGG repeats. Unprogrammed RRL reactions lacking external DNA template were used as negative controls (lanes 1 and 4), and a reaction with asparagus POT1 protein (Ao POT1) was performed as a positive control (lane 3). Pp POT1 binds 3TELO probe (lane 5) but not 2TELO probe (lane 2).

(B) Identification of the Pp POT1 minimum DNA binding site. Equal amounts of RRL-expressed Pp POT1 were incubated with the indicated radioactively labeled oligonucleotides (bottom panel), and protein-DNA complexes were separated by native PAGE.