This question is wrecking my brain

[focusinc]

Treatmentof a tetranucleotide with Snake Venom Phosphodiesterase yielded pGp, pT, pC,and pC. Prior treatment with aphosphomonoesterase (phosphatase) followed by Snake Venom Phosphodiesteraseyielded pC, pC, pG, and T. What is the sequence of the tetranucleotide? Explainyour reasoning.

If someone could put me in the right direction

[cypress]

You need to first understand what Phosphodiesterase does to a diester and what phosphatase does to a substrate. From that and the differences in the products you can determine which of the bases are in the center of the tetranucleotide and which ones are on the ends.