HADDOCK Webserver MAXCN Error

HADDOCK
1

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
Manuel

2

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.

3

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.

4

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

5

Thanks a lot for your help!

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