(A) A representative gel shift used to determine the binding of POT1-TPP1 protein to ssDNA under equilibrium binding conditions. The lower band represents free, radiolabeled ssDNA, and the upper band indicates ssDNA-protein complex.
(B) Gel shift data were quantified and fitted to calculate dissociation constants (KDs) of POT1-TPP1 for several substrates with native thymidine replaced with 5-FdUTP. Data are represented as mean ± SEM (n = 3).
(C) A table summarizing the results indicates that 5-FdUTP exhibits differing positional effects on POT1-TPP1 binding affinity for ssDNA substrates.