Prediction of the active site of a protein complex

Question

[Curious]

I need to predict the active site of a homodimeric protein that has 3128 amino acid residues (its structure wasn't known, so I made the prediction with a server). I tried to do this with GHECOM, but it didn't work because it only accepts up to 10000 receptor atoms and the protein I'm working on has more than 46500. Please give me some tools to do this job.

GHECOM website: https://pdbj.org/ghecom/