Structure Prediction of Transcription Factor and its binding site to a promoter element

Hello,

I have a wild type sequence of a transcription factor. I had predicted its structure using I-Tasser. I have a hunch that the structure might be a tetramer, although here I am getting it as a monomer. What should I do in this case ? The sites involved in binding is said to be 1-150 aa (from literature). I know the sequence of the promoter element (DNA) to which it binds. How do I model the ligand so that I could dock?

Thanks