Hi, I am currently refining a structure of a glycosylated protein, but I fail to define the appropriate links... The glycosylatin is Asn638-NAG1061-(beta1-4)-NAG1062-(beta1-4)-BMA1063-(ALPHA1-3)-MAN1064 This is what I add in the eff file : apply_cif_link { data_link = NAG-ASN residue_selection_1 = chain D and resname NAG and resid 1061 residue_selection_2 = chain A and resname ASN and resid 638 } apply_cif_link { data_link = BETA1-4 residue_selection_1 = chain D and resname NAG and resid 1062 residue_selection_2 = chain D and resname NAG and resid 1061 } apply_cif_link { data_link = BETA1-4 residue_selection_1 = chain D and resname BMA and resid 1063 residue_selection_2 = chain D and resname NAG and resid 1062 } apply_cif_link { data_link = ALPHA1-3 residue_selection_1 = chain D and resname MAN and resid 1064 residue_selection_2 = chain D and resname BMA and resid 1063 } this is correctly read in refine: apply_cif_link: data_link: NAG-ASN mod_id_1: DEL-O1 mod_id_2: DEL-HD22 residue_selection_1: chain D and resname NAG and resid 1061 residue_selection_2: chain A and resname ASN and resid 638 apply_cif_link: data_link: BETA1-4 mod_id_1: DEL-HO4 mod_id_2: DEL-O1 residue_selection_1: chain D and resname NAG and resid 1062 residue_selection_2: chain D and resname NAG and resid 1061 apply_cif_link: data_link: BETA1-4 mod_id_1: DEL-HO4 mod_id_2: DEL-O1 residue_selection_1: chain D and resname BMA and resid 1063 residue_selection_2: chain D and resname NAG and resid 1062 apply_cif_link: data_link: ALPHA1-3 mod_id_1: DEL-HO3 mod_id_2: DEL-O1 residue_selection_1: chain D and resname MAN and resid 1064 residue_selection_2: chain D and resname BMA and resid 1063 but generates an error : Number of atoms with unknown nonbonded energy type symbols: 5 "HETATM10951 HO4 NAG D1052 .*. H " "HETATM10973 HO4 BMA D1053 .*. H " "HETATM11028 HO4 NAG D1062 .*. H " "HETATM11050 HO4 BMA D1063 .*. H " "HETATM11070 HO3 MAN D1064 .*. H " and the job stops. Any ideas on what if wrong ? thanks for your help Laurent -- ---------------------------------------------------------- Laurent Maveyraud laurent.maveyraud AT ipbs DOT fr P I C T --- Plateforme Intégrée de Criblage de Toulouse Université Paul Sabatier / CNRS / I.P.B.S. UMR 5089 Département Biologie Structurale et Biophysique http://cribligand.ipbs.fr http://www.ipbs.fr 205 route de Narbonne 31077 TOULOUSE Cedex FRANCE Tél: +33 (0)561 175 435 Fax : +33 (0)561 175 994 ----------------------------------------------------------