Which enzyme catalyzes the breaking of phosphodiester bonds in nucleic acids?

The enzyme that catalyzes the breaking of phosphodiester bonds in nucleic acids is phosphodiesterase. This enzyme specifically hydrolyzes the phosphodiester bonds that connect the nucleotides in the backbone of DNA and RNA, resulting in the cleavage of the nucleic acid strand. Phosphodiesterases are crucial in processes such as nucleic acid degradation and can also play a role in cellular signaling by modulating levels of nucleotide signaling molecules.

DNA polymerase, on the other hand, is primarily involved in synthesizing new strands of DNA by forming phosphodiester bonds rather than breaking them. RNA polymerase serves a similar purpose for RNA, synthesizing RNA from a DNA template and also forming phosphodiester bonds during this process. Ligase is responsible for joining nucleic acid fragments by creating phosphodiester bonds, particularly in the context of DNA replication and repair, rather than breaking them. Therefore, phosphodiesterase is the correct choice as it directly catalyzes the cleavage of the bonds that hold nucleic acid strands together.