If the active site tyrosine of a topoisomerase I were mutated to phenylalanine, which of the following statements is most likely to be true?
A) The mutant topoisomerase will break both strands of the backbone.
B) The mutant topoisomerase will not bind DNA.
C) The mutant topoisomerase will break the phosphodiester bond of its DNA substrate, but the DNA will exit the active site before repair.
D) The mutant topoisomerase will not break the phosphodiester bond of its DNA substrate.