Can I assign more than one tempalte when submitting a protein sequence for I-TASSER?

Hi!

For my experiments, I am working with a fusion protein consisting out of three proteins, for which the crystal structures are known. I would like to use I-Tasser to model how the fusion protein including the three proteins and linkers between them will look like. To get the best result, I have assigned the PDB file of the largest of these three proteins together with the sequnce of the whole fusion protein in I-TASSER. While this part looks perfectly fine in the result, the rest of the protein has not the correct structure. Is it possible to assign all three PDB files in order to get a better result?
Is there anything else I can do?

Best,
Jan