Question

a stretch of which nucleotide in the DNA acts as the terminationsignal​

Answer 1

After the RNA polymerase binds tightly to the promoter DNA in this way, it opens up the double helix to expose a short stretch of nucleotides on each strand (Step 2 in Figure 6-10). Unlike a DNA helicase reaction (see Figure 5-15), this limited opening of the helix does not require the energy of ATP hydrolysis.