Cannot select both chains of MHC II complex for docking

Hello,
I want to dock peptide with mhcii complex with both chains, ie. A and B but after uploading the pdb file in haddock webserver, How do I involve both chains for docking? Thanks!!

Each molecule must consist of a unique chain.

I.e. you might have to combine your A and B chains into one single chain with non-overlapping residue numbering

The forum is searchable and this question has been answered multiple times :slight_smile: