Initiation of RNA Biosynthesis Involves

Question

Initiation of RNA biosynthesis involves
A) recognition of the promoter region by the α subunit of RNA polymerase
B) conversion of the closed-promoter complex to the open-promoter complex
C) binding of one of the α subunits of RNA polymerase to each strand of DNA
D) incorporation of four pyrimidine nucleotides in succession

Accepted Answer

Initiation of RNA biosynthesis involves conversion of the closed-promoter complex to the open-promoter complex, which allows binding of the RNA polymerase and incorporation of nucleotides to form the RNA strand. Recognition of the promoter region by the α subunit of RNA polymerase and binding of the α subunits of RNA polymerase to the DNA strand occur before the conversion of the closed-promoter complex to the open-promoter complex. Incorporation of nucleotides occurs after the initiation of RNA biosynthesis by the RNA polymerase. Therefore, option B is the best choice as it describes the initial step in RNA biosynthesis.