HADDOCK Webserver MAXCN Error

Dear all

I tried to dock two proteins using HADDOCK’s easy interface.
Processing was successful. However, I received an error during the rigid docking stage:

%PARRDR error encountered: exceeded MAXCN (PARAM) parameter --> recompile program
(CNS is in mode: SET ABORT=NORMal END)

Since I used the easy interface, I did not specify any restraints. There must be a problem in my pdb files, but I can’t seem to find it. Does anyone of you know what could have caused this error?

Kind regards

Dear Manuel,

Even using the easy interface, you must supply restraints (active residues). Please provide data for both molecules to drive the docking, in the form of comma-separated list of residue numbers.

Thanks for your reply!

I actually supplied the active residues. I also made sure that they are at least 40% solvent accessible (using naccess) and double checked using CPORT.
However, I still get the “exceeded MAXCN” error.

You must have a lot of small molecules / crystallisation junk left as HETATM in your proteins (or a lot of co-factors).
Remove everything unnecessary

Thanks a lot for your help!

I indeed had four cofactors in my proteins. After removing three of them, it worked!