2022 Denovo tutorial 3 with PDBID 1X70
Focused Denovo Design
In this tutorial, we will be making a focus fragment library from the crystallographic ligand for PDB 1X70 and then attempting to rebuild the cognate ligand with the library we generated.
Ligand Fragmentation
ATTENTION: This tutorial requires you to have first completed the 2022 1X70 VS tutorial: https://ringo.ams.stonybrook.edu/index.php/2022_DOCK_tutorial_3_with_PDBID_1X70
Make a new directory:
mkdir 09.focus_dn
Now inside 09.focus_dn, make the following DOCK6 input file: "fraglib.in"
conformer_search_type flex write_fragment_libraries yes fragment_library_prefix fraglib fragment_library_freq_cutoff 1 fragment_library_sort_method freq fragment_library_trans_origin no use_internal_energy yes internal_energy_rep_exp 12 internal_energy_cutoff 100.0 ligand_atom_file ../01.structures/715.mol2 limit_max_ligands no skip_molecule no read_mol_solvation no calculate_rmsd no use_database_filter no orient_ligand yes automated_matching yes receptor_site_file ../02.spheres/selected_spheres.sph max_orientations 1000 critical_points no chemical_matching no use_ligand_spheres no bump_filter no score_molecules no atom_model all vdw_defn_file /gpfs/projects/AMS536/zzz.programs/dock6.9_release/parameters/vdw_AMBER_parm99.defn flex_defn_file /gpfs/projects/AMS536/zzz.programs/dock6.9_release/parameters/flex.defn flex_drive_file /gpfs/projects/AMS536/zzz.programs/dock6.9_release/parameters/flex_drive.tbl ligand_outfile_prefix fragment.out write_orientations no num_scored_conformers 1 rank_ligands no
dock6 -i fraglib.in -o fraglib.out
You should end up with 5 different files:
"fraglib_rigid.mol2 fraglib_scaffold.mol2 fraglib_sidechain.mol2 fraglib_torenv.dat fraglib_linker.mol2"
Each file contains fragments defined by the number of places they were cut at during fragment generation.
Now load up Chimera:
Tools > Binding/Surface Analysis > View Dock > Load fraglib_linker.mol2
Load fraglib_sidechain.mol2
Load both
Focused Growth
Make the following dock6 input file: "focus.in"
conformer_search_type denovo dn_fraglib_scaffold_file fraglib_scaffold.mol2 dn_fraglib_linker_file fraglib_linker.mol2 dn_fraglib_sidechain_file fraglib_sidechain.mol2 dn_user_specified_anchor no dn_use_torenv_table yes dn_torenv_table fraglib_torenv.dat dn_sampling_method graph dn_graph_max_picks 30 dn_graph_breadth 3 dn_graph_depth 2 dn_graph_temperature 100.0 dn_pruning_conformer_score_cutoff 100.0 dn_pruning_conformer_score_scaling_factor 1.0 dn_pruning_clustering_cutoff 100.0 dn_constraint_mol_wt 550.0 dn_constraint_rot_bon 15 dn_constraint_formal_charge 2.0 dn_heur_unmatched_num 1 dn_heur_matched_rmsd 2.0 dn_unique_anchors 4 dn_max_grow_layers 9 dn_max_root_size 25 dn_max_layer_size 25 dn_max_current_aps 5 dn_max_scaffolds_per_layer 1 dn_write_checkpoints yes dn_write_prune_dump no dn_write_orients yes dn_write_growth_trees yes dn_output_prefix dn_focus.out use_internal_energy yes internal_energy_rep_exp 12 internal_energy_cutoff 100.0 use_database_filter no orient_ligand yes automated_matching yes receptor_site_file ../02.spheres/selected_spheres.sph max_orientations 1000 critical_points no chemical_matching no use_ligand_spheres no bump_filter no score_molecules yes contact_score_primary no contact_score_secondary no grid_score_primary yes grid_score_secondary no grid_score_rep_rad_scale 1 grid_score_vdw_scale 1 grid_score_es_scale 1 grid_score_grid_prefix ../03.grid/grid multigrid_score_secondary no dock3.5_score_secondary no continuous_score_secondary no footprint_similarity_score_secondary no pharmacophore_score_secondary no descriptor_score_secondary no gbsa_zou_score_secondary no gbsa_hawkins_score_secondary no SASA_score_secondary no amber_score_secondary no minimize_ligand yes minimize_anchor yes minimize_flexible_growth yes use_advanced_simplex_parameters no simplex_max_cycles 1 simplex_score_converge 0.1 simplex_cycle_converge 1.0 simplex_trans_step 1.0 simplex_rot_step 0.1 simplex_tors_step 10.0 simplex_anchor_max_iterations 500 simplex_grow_max_iterations 500 simplex_grow_tors_premin_iterations 0 simplex_random_seed 0 simplex_restraint_min no atom_model all vdw_defn_file /gpfs/projects/AMS536/zzz.programs/dock6.9_release/parameters/vdw_de_novo.defn flex_defn_file /gpfs/projects/AMS536/zzz.programs/dock6.9_release/parameters/flex.defn flex_drive_file /gpfs/projects/AMS536/zzz.programs/dock6.9_release/parameters/flex_drive.tbl
dock6 -i focus.in -o focus.out
You should get the following file: "dn_focus.out.denovo_build.mol2"
Load in the denovo results Chimera using viewdock, then load in the refence ligand:
Tools > general controls > model panel > set the reference ligand to inactive and then move the fragments so they are not overlayed
As we can see, the top scoring poses consist of the original crystallographic ligand in various posses.