Final answer:
The RNA polymerase binds to the promoter with the aid of transcription factors, especially TFIID, to form an initiation complex required to start the transcription process of DNA into RNA.
Step-by-step explanation:
The RNA polymerase molecule binds to the promoter prior to initiating transcription with the help of several proteins known as transcription factors. In eukaryotic cells, the RNA polymerase requires these transcription factors to first bind to the promoter region and then help recruit the RNA polymerase. Within the promoter region, particularly the TATA box, the transcription factor TFIID binds first, which recruits additional transcription factors like TFIIB, TFIIE, TFIIF, and TFIIH. It is this assembly of transcription factors and RNA polymerase forming an initiation complex at the promoter that initiates transcription of DNA into RNA.
Upon binding, RNA polymerase is typically phosphorylated, altering its conformation and enabling it to begin the transcription process. During this process, a region of DNA unwinds to form a transcription bubble, allowing the RNA polymerase to synthesize RNA using the antisense strand of the DNA as a template.