Which enzyme is known as topoisomerase?

Topoisomerase refers to a class of enzymes that are crucial in managing the topological states of DNA during processes such as replication, transcription, and recombination. Gyrase is a specific type of topoisomerase found primarily in bacteria. Its primary function is to introduce negative supercoils into DNA, which helps relieve the torsional strain that occurs ahead of the replication fork as DNA unwinds. This action is vital for proper DNA replication and is also important in other cellular processes that involve DNA.

By contrast, DNA ligase is responsible for joining together DNA fragments, particularly during the lagging strand synthesis, and repairing DNA. DNA polymerase plays an essential role in synthesizing new DNA strands by adding nucleotides to an existing DNA template and is mainly involved in DNA replication. Primase synthesizes short RNA primers needed for starting DNA replication. While these enzymes are all integral to DNA metabolism, gyrase distinctly serves the purpose of resolving DNA supercoiling, categorizing it specifically as a topoisomerase.