Question

In Chapter 11, we discussed the function of DNA helicase, which is involved in DNA replication. Discuss how the functions of \(\rho\)-protein and DNA helicase are similar and how they are different.

Short answer

DNA helicase and \(\rho\)-protein both function to separate the strands of the DNA helix. However, DNA helicase does this during DNA replication to allow new strands to be synthesized, while \(\rho\)-protein acts during transcription to release the newly formed RNA strand from the DNA template.

Step-by-step solution

Understanding the function of DNA helicase

DNA helicase is the enzyme that unwinds the DNA double helix during DNA replication. It breaks the hydrogen bonds that hold the two DNA strands together, creating a replication fork with two single strands of DNA that can be used as templates for replication.

Understanding the function of \(\rho\)-protein

\(\rho\)-protein is a termination factor for DNA replication in bacteria. It breaks the hydrogen bonds between the RNA in the RNA-DNA hybrid region of the transcription complex, causing the RNA strand to be released from the DNA template.

Comparing and contrasting DNA helicase and \(\rho\)-protein

Both DNA helicase and \(\rho\)-protein are involved in separating the strands of the DNA double helix, but they do so under different circumstances and for different reasons. DNA helicase operates during DNA replication to separate the two DNA strands, allowing new DNA strands to be synthesized. On the other hand, \(\rho\)-protein operates during the transcription process to release the newly synthesized RNA strand from the DNA template.