Final answer:
Gyrase and topoisomerase are the two enzymes that assist RNA polymerase in relieving supercoiling during transcription by introducing negative supercoils and nicking the DNA strands to enable rotation, respectively. The correct answer to the question is C. Gyrase; topoisomerase.
Step-by-step explanation:
The two enzymes that help RNA polymerase (RNAP) to eliminate supercoiling generated by the mechanism of transcription are gyrase and topoisomerase. The correct answer is C. Gyrase; topoisomerase.
Gyrase, which is specifically type II topoisomerase, introduces negative supercoils into the DNA, which helps in compensating for the positive supercoils that form ahead of the transcription machinery. Meanwhile, topoisomerases in general can create nicks in the DNA strands, allowing them to rotate around each other and thereby relax the supercoils.
During transcription, RNAP traverses the DNA template, which can cause the DNA to become over-wound in front of the transcription bubble and under-wound behind it. These changes in DNA supercoiling, if not addressed, can hinder the progress of transcription and eventually damage the DNA. Gyrase and topoisomerase play crucial roles in managing DNA topology to ensure efficient and accurate transcription.