Re: [Rdkit-discuss] MolFromPDBBlock and heterocycles
Hi Steven, The PDB reader in the RDKit doesn’t determine any bond orders - everything is read as a single bond. In order to set the bond orders, you need to call the AssignBondOrdersFromTemplate() function using a reference molecule generated from SMILES (or SDF). Here is some example code from the docs: >>> from rdkit.Chem import AllChem >>> template = AllChem.MolFromSmiles("CN1C(=NC(C1=O)(c2c2)c3c3)N") >>> mol = AllChem.MolFromPDBFile(os.path.join(RDConfig.RDCodeDir, 'Chem', 'test_data', '4DJU_lig.pdb')) >>> len([1 for b in template.GetBonds() if b.GetBondTypeAsDouble() == 1.0]) 8 >>> len([1 for b in mol.GetBonds() if b.GetBondTypeAsDouble() == 1.0]) 22 Now assign the bond orders based on the template molecule >>> newMol = AllChem.AssignBondOrdersFromTemplate(template, mol) >>> len([1 for b in newMol.GetBonds() if b.GetBondTypeAsDouble() == 1.0]) 8 Note that the template molecule should have no explicit hydrogens else the algorithm will fail. Hope this helps. Best, Sereina 2016-09-07 17:16 GMT+02:00 Steven Combs: > Hello! > > I have a pdb block that I am working with, which is attached to this > email. The ligand has aromatic ring structures in it; however, when it is > read into RDKit and converted into a smiles string, the aromatic rings are > converted into aliphatic rings. Any thoughts? > > Here is the python code: > > def extract_data( filename): > extracted_info = "" > with open(filename) as f: > for line in f.readlines(): > if "HETATM" in line: > extracted_info += ( line) > return extracted_info > > for index, filename in enumerate(solution_pdb_filenames): > row = extract_data( filename) > m = Chem.MolFromPDBBlock(row, sanitize=True, removeHs=False ) > Chem.SetHybridization(m) > Chem.SetAromaticity(m) > Chem.SanitizeMol(m, > sanitizeOps=Chem.rdmolops.SanitizeFlags.SANITIZE_ALL) > #not needed since sanitizing during read in, but trying to figure out if it > actually worked > print ("Parsing file " + str(index) + " of " + > str(len(solution_pdb_filenames))) > print (Chem.MolToSmiles(m, kekuleSmiles=True, allHsExplicit=True)) > > The output smile string is: > > [H][O][CH]1[NH][CH]([C]([H])([H])[CH]([OH])[OH])[CH]([C]([H] > )([H])[C]([H])([H])[H])[CH]([CH]([OH])[CH]2[CH]([H])[CH]([ > H])[CH]([H])[CH]([N]([H])[H])[CH]2[H])[CH]1[N]([C]([H])([H]) > [H])[C]([H])([H])[H] > > Steven Combs > > > > > -- > > ___ > Rdkit-discuss mailing list > Rdkit-discuss@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/rdkit-discuss > > -- ___ Rdkit-discuss mailing list Rdkit-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rdkit-discuss
Re: [Rdkit-discuss] MolFromPDBBlock and heterocycles
Hi Steven, The PDB reader in the RDKit doesn’t determine any bond orders - everything is read as a single bond. In order to set the bond orders, you need to call the AssignBondOrdersFromTemplate() function using a reference molecule generated from SMILES (or SDF). Here is some example code from the docs: >>> from rdkit.Chem import AllChem >>> template = AllChem.MolFromSmiles("CN1C(=NC(C1=O)(c2c2)c3c3)N") >>> mol = AllChem.MolFromPDBFile(os.path.join(RDConfig.RDCodeDir, 'Chem', >>> 'test_data', '4DJU_lig.pdb')) >>> len([1 for b in template.GetBonds() if b.GetBondTypeAsDouble() == 1.0]) 8 >>> len([1 for b in mol.GetBonds() if b.GetBondTypeAsDouble() == 1.0]) 22 Now assign the bond orders based on the template molecule >>> newMol = AllChem.AssignBondOrdersFromTemplate(template, mol) >>> len([1 for b in newMol.GetBonds() if b.GetBondTypeAsDouble() == 1.0]) 8 Note that the template molecule should have no explicit hydrogens else the algorithm will fail. Hope this helps. Best, Sereina On 07 Sep 2016, at 17:16, Steven Combswrote: > Hello! > > I have a pdb block that I am working with, which is attached to this email. > The ligand has aromatic ring structures in it; however, when it is read into > RDKit and converted into a smiles string, the aromatic rings are converted > into aliphatic rings. Any thoughts? > > Here is the python code: > > def extract_data( filename): > extracted_info = "" > with open(filename) as f: > for line in f.readlines(): > if "HETATM" in line: > extracted_info += ( line) > return extracted_info > > for index, filename in enumerate(solution_pdb_filenames): > row = extract_data( filename) > m = Chem.MolFromPDBBlock(row, sanitize=True, removeHs=False ) > Chem.SetHybridization(m) > Chem.SetAromaticity(m) > Chem.SanitizeMol(m, > sanitizeOps=Chem.rdmolops.SanitizeFlags.SANITIZE_ALL) #not needed since > sanitizing during read in, but trying to figure out if it actually worked > print ("Parsing file " + str(index) + " of " + > str(len(solution_pdb_filenames))) > print (Chem.MolToSmiles(m, kekuleSmiles=True, allHsExplicit=True)) > > The output smile string is: > > [H][O][CH]1[NH][CH]([C]([H])([H])[CH]([OH])[OH])[CH]([C]([H])([H])[C]([H])([H])[H])[CH]([CH]([OH])[CH]2[CH]([H])[CH]([H])[CH]([H])[CH]([N]([H])[H])[CH]2[H])[CH]1[N]([C]([H])([H])[H])[C]([H])([H])[H] > > Steven Combs > > > -- > ___ > Rdkit-discuss mailing list > Rdkit-discuss@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/rdkit-discuss -- ___ Rdkit-discuss mailing list Rdkit-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rdkit-discuss
[Rdkit-discuss] MolFromPDBBlock and heterocycles
Hello! I have a pdb block that I am working with, which is attached to this email. The ligand has aromatic ring structures in it; however, when it is read into RDKit and converted into a smiles string, the aromatic rings are converted into aliphatic rings. Any thoughts? Here is the python code: def extract_data( filename): extracted_info = "" with open(filename) as f: for line in f.readlines(): if "HETATM" in line: extracted_info += ( line) return extracted_info for index, filename in enumerate(solution_pdb_filenames): row = extract_data( filename) m = Chem.MolFromPDBBlock(row, sanitize=True, removeHs=False ) Chem.SetHybridization(m) Chem.SetAromaticity(m) Chem.SanitizeMol(m, sanitizeOps=Chem.rdmolops.SanitizeFlags.SANITIZE_ALL) #not needed since sanitizing during read in, but trying to figure out if it actually worked print ("Parsing file " + str(index) + " of " + str(len(solution_pdb_filenames))) print (Chem.MolToSmiles(m, kekuleSmiles=True, allHsExplicit=True)) The output smile string is: [H][O][CH]1[NH][CH]([C]([H])([H])[CH]([OH])[OH])[CH]([C]([H])([H])[C]([H])([H])[H])[CH]([CH]([OH])[CH]2[CH]([H])[CH]([H])[CH]([H])[CH]([N]([H])[H])[CH]2[H])[CH]1[N]([C]([H])([H])[H])[C]([H])([H])[H] Steven Combs test.pdb Description: Protein Databank data -- ___ Rdkit-discuss mailing list Rdkit-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rdkit-discuss