RNA Polymerase II

RNA polymerase II (also called RNAP II and Pol II) is an enzyme found in eukaryotic cells. It catalyzes the transcription of DNA to synthesize precursors of mRNA and most snRNA and microRNA. A 550 kDa complex of 12 subunits, RNAP II is the most studied type of RNA polymerase. A wide range of transcription factors are required for it to bind to its promoters and begin transcription.

Read more about RNA Polymerase II:  Subunits, Assembly, Kinetics, Holoenzyme, Control By Chromatin Structure, Protein Complexes Involved, N-terminus, C-terminus