Final answer:
While the materials provided refer to prokaryotic RNA polymerase, the question pertains to RNA Pol II in eukaryotes, which has a complex of 12 different subunits for its function. RNA Pol II's largest subunit, RPB1, contains the active site essential for enzymatic activity.
Step-by-step explanation:
The enzymatic activity of RNA Polymerase II (RNA Pol II), which is primarily involved in eukaryotic transcription, depends on a complex of subunits. While the student's question refers to RNA Pol II, the provided reference materials focus on prokaryotic RNA polymerase. Still, the principle that multiple subunits are required for polymerase function is a common theme. In eukaryotes, RNA Pol II consists of 12 subunits (RPB1-RPB12), with the largest subunit, RPB1, containing the active site. These subunits work together to ensure the accurate transcription of genetic material into messenger RNA (mRNA). For Prokaryotic RNA Polymerase, which is slightly different from eukaryotic RNA Pol II, the core enzyme is composed of the alpha (α), beta (β), and beta-prime (β') subunits. It is the sigma factor (σ) that is specifically required for transcription initiation in prokaryotes, guiding RNA polymerase to the correct initiation sites.