Protein-Lipid_membrane docking on the HADDOCK webserver

I have been trying to dock a small protein to a lipid_membrane, and much literature has lead me to the HADDOCK webserver. My membrane was prepared using CHAMM GUI. I have tried editing the membrane PDB file as required by making sure all ATOMS are changed to HETATM. However, parsing at line 2 of the lipid_membrane PDB file has continuously failed. Is it true that the webserver surely supports this kind of docking job? If yes, how do I go about it further?

try to keep only the HETATM lines and the final END line, removing all the “junk” in the header

run the file through pdb_tidy and pdb_validate from our pdb-tools

Thank you for your advice on how to tackle the above task. My membrane has POPE, POPG and Cardiolipin (Abbrev. from CHAMM GUI as TMCL). I used pdb_tidy and validated. The pdb_validate returned some errors still but note on line 1. However, I tested by submitting to the webserver, line 1 couldn’t be parsed still, citing line incompatibility.
My questions are,

  1. Is it right to edit POPE to PE5 as seen from one person in the community who has phospholipid names as “PC5”?
  2. What other modifications can I do to my pdb file?
  3. It was mentioned that we should choose “other” or “small molecule” as molecule type, but I don’t see any of such even with expert access. How do I go about that? Thank you very much for your help

try selecting ligand (stands for small molecule)