And this complex is necessary for transcription to actually take place. So we have this complex of proteins that binds onto our Tata box and then basically calls upon other proteins, those other proteins bind, forming a larger complex and so forth. And eventually that interacts with the protein found at the start side and that initiates the process of RNA transcription. So two important types of proteins you should be familiar with is transcription factor two D and transcription factor two B. Now, transcription factor 2D is itself a complex of many proteins, and one of the important proteins within the transcription factor 2D is known as the Tata binding protein or TBP. And this is the protein that actually binds to the sequence Tata found on the core promoter.