I am reading through my textbook (Genetics, Brooker 4th edition) and the summary it gives seems imprecise for the functionality of helicase and topoisomerase.
The following is an exerpt:
At each replication fork, DNA helicase unwinds the DNA and topisomerase alleviates positive supercoiling.
Is it proper to say that helicase "unwinds" DNA? In other places in the book, it says the function of helicase is to separate the two strands of DNA, and topoisomerase "relieves the supercoiling" caused by the strand separation activity of helicase.
Pardon my ignorance, but it seems rather like helicase actually induces more winding, and topoisomerase (gyrase) actually unwinds DNA.
Is this just a case of poor wording, or does helicase actually somehow unwind (untwist) DNA? I am finding this particularly frustrating because virtually every resource I can find says that
helicase unwinds DNA, but based on the mechanisms they offer, it definitely does not "unwind".