[gmx-users] pdb2gmx error

[Saman Shahriyari]

Dear Users
I am trying to run pdb2gmx (in gromacs 5.0.5 and by 43a1p.ff) on o modeled structure holding ATP, water and TPO as hetero atoms. but I am faced with the following error. I checked all LUE residues (although I have got no residue with 28215089 number) and I found no missing atom N. I am really wondering what should be my next step. could you help me on this? 
"Fatal error:Residue 28215089 named LEU of a molecule in the input file was mapped to an entry in the topology database, but the atom N used in an interaction of type improper in that entry is not found in the input file. Perhaps your atom and/or residue naming needs to be fixed."
Best regardsSaman