RNA poylmerase is the enzyme involved in transcription. It plays a pivotal role in the synthesis of RNA from a DNA template, making it essential to the gene expression that occurs in all known life.
Transcription is the process by which RNA is replicated from an original template of DNA. In order for the conversion of DNA to RNA to occur, RNA polymerase must step in and bind proteins known as transcription factors to a section of the DNA known as the promoter. The RNA polymerase can then read the DNA sequence and produce an RNA strand known as the primary transcript. Transcription often results in mRNA, or messenger RNA, which then goes through translation to complete protein synthesis.