Files
propka/Source/conformation_container.py
Matvey Adzhigirey 2079259884 Improve Python 2 compatability with "future" print_function.
Use python3 version of the print function when running
under python2. Also added "from __future__ import division"
to a few more module files.
2012-12-20 11:29:41 -05:00

443 lines
16 KiB
Python

#
# Container for molecular conformations
#
from __future__ import division
from __future__ import print_function
import Source.group, Source.determinants, Source.determinant, Source.ligand, Source.output, Source.coupled_groups, functools
class Conformation_container:
def __init__(self, name='', parameters=None, molecular_container=None):
self.molecular_container = molecular_container
self.name=name
self.parameters=parameters
self.atoms = []
self.groups = []
self.chains = []
self.current_iter_item = 0
self.marvin_pkas_calculated = False
self.non_covalently_coupled_groups = False
return
#
# Group related methods
#
def extract_groups(self):
""" Generates at list of molecular groups needed for calculating pKa values """
for atom in self.get_non_hydrogen_atoms():
# has this atom been checked for groups?
if atom.groups_extracted == 0:
self.validate_group(Source.group.is_group(self.parameters, atom))
# if the atom has been checked in a another conformation, check if it has a
# group that should be used in this conformation as well
elif atom.group:
self.validate_group(atom.group)
return
def additional_setup_when_reading_input_file(self):
# if a group is coupled and we are reading a .propka_input file,
# some more configuration might be needed
# print coupling map
map = Source.output.make_interaction_map('Covalent coupling map for %s'%self,
self.get_covalently_coupled_groups(),
lambda g1,g2: g1 in g2.covalently_coupled_groups)
print(map)
# check if we should set a common charge centre as well
if self.parameters.common_charge_centre:
self.set_common_charge_centres()
return
def set_common_charge_centres(self):
for system in self.get_coupled_systems(self.get_covalently_coupled_groups(), Source.group.Group.get_covalently_coupled_groups):
# make a list of the charge centre coordinates
all_coordinates = list(map(lambda g: [g.x, g.y, g.z], system))
# find the common charge center
ccc = functools.reduce(lambda g1,g2: [g1[0]+g2[0], g1[1]+g2[1], g1[2]+g2[2]], all_coordinates)
ccc = list(map(lambda c: c/len(system), ccc))
# set the ccc for all coupled groups in this system
for g in system:
[g.x, g.y, g.z] = ccc
g.common_charge_centre = True
return
def find_covalently_coupled_groups(self):
""" Finds covalently coupled groups and sets common charge centres if needed """
for group in [ group for group in self.groups if group.titratable]:
# Find covalently bonded groups
bonded_groups = self.find_bonded_titratable_groups(group.atom, 1, group.atom)
# couple groups
for cg in bonded_groups:
if cg in group.covalently_coupled_groups:
continue
if cg.atom.sybyl_type == group.atom.sybyl_type:
group.couple_covalently(cg)
# check if we should set a common charge centre as well
if self.parameters.common_charge_centre:
self.set_common_charge_centres()
# print coupling map
map = Source.output.make_interaction_map('Covalent coupling map for %s'%self,
#self.get_titratable_groups(),
self.get_covalently_coupled_groups(),
lambda g1,g2: g1 in g2.covalently_coupled_groups)
print(map)
return
def find_non_covalently_coupled_groups(self, verbose=False):
# check if non-covalent coupling has already been set up in an input file
if len(list(filter(lambda g: len(g.non_covalently_coupled_groups)>0, self.get_titratable_groups())))>0:
self.non_covalently_coupled_groups = True
Source.coupled_groups.nccg.identify_non_covalently_coupled_groups(self,verbose=verbose)
# re-do the check
if len(list(filter(lambda g: len(g.non_covalently_coupled_groups)>0, self.get_titratable_groups())))>0:
self.non_covalently_coupled_groups = True
return
def find_bonded_titratable_groups(self, atom, no_bonds, original_atom):
res = set()
for ba in atom.bonded_atoms:
# skip the original atom
if ba == original_atom:
continue
# check if this atom has a titratable group
if ba.group and ba.group.titratable and no_bonds <= self.parameters.coupling_max_number_of_bonds:
res.add(ba.group)
# check for titratable groups bonded to this atom
if no_bonds < self.parameters.coupling_max_number_of_bonds:
res |= self.find_bonded_titratable_groups(ba,no_bonds+1, original_atom)
return res
def validate_group(self, group):
""" Checks if we want to include this group in the calculations """
# Is it recognized as a group at all?
if not group:
return
# Other checks (include ligands, which chains etc.)
# if all ok, accept the group
self.accept_group(group)
return
def accept_group(self, group):
# set up the group
group.parameters=self.parameters
group.setup()
# and store it
self.groups.append(group)
return
#
# pka calculation methods
#
def calculate_pka(self, version, options):
print('\nCalculating pKas for',self)
# calculate desolvation
for group in self.get_titratable_groups()+self.get_ions():
version.calculate_desolvation(group)
# calculate backbone interactions
Source.determinants.setBackBoneDeterminants(self.get_titratable_groups(), self.get_backbone_groups(), version)
# setting ion determinants
Source.determinants.setIonDeterminants(self, version)
# calculating the back-bone reorganization/desolvation term
version.calculateBackBoneReorganization(self)
# setting remaining non-iterative and iterative side-chain & Coulomb interaction determinants
Source.determinants.setDeterminants(self.get_sidechain_groups(), version=version, options=options)
# calculating the total pKa values
for group in self.groups: group.calculate_total_pka()
# take coupling effects into account
penalised_labels = self.coupling_effects()
if self.parameters.remove_penalised_group and len(penalised_labels)>0:
print('Removing penalised groups!!!')
for g in self.get_titratable_groups():
g.remove_determinants(penalised_labels)
# re-calculating the total pKa values
for group in self.groups: group.calculate_total_pka()
return
def coupling_effects(self):
#
# Bases: The group with the highest pKa (the most stable one in the
# charged form) will be the first one to adopt a proton as pH
# is lowered and this group is allowed to titrate.
# The remaining groups are penalised
#
# Acids: The group with the highest pKa (the least stable one in the
# charged form) will be the last group to loose the proton as
# pH is raised and will be penalised.
# The remaining groups are allowed to titrate.
#
penalised_labels = []
for all_groups in self.get_coupled_systems(self.get_covalently_coupled_groups(),
Source.group.Group.get_covalently_coupled_groups):
# check if we should share determinants
if self.parameters.shared_determinants:
self.share_determinants(all_groups)
# find the group that has the highest pKa value
first_group = max(all_groups, key=lambda g:g.pka_value)
# In case of acids
if first_group.charge < 0:
first_group.coupled_titrating_group = min(all_groups, key=lambda g:g.pka_value)
penalised_labels.append(first_group.label) # group with the highest pKa is penalised
# In case of bases
else:
for a in all_groups:
if a == first_group:
continue # group with the highest pKa is allowed to titrate...
a.coupled_titrating_group = first_group
penalised_labels.append(a.label) #... and the rest is penalised
return penalised_labels
def share_determinants(self, groups):
# make a list of the determinants to share
types = ['sidechain','backbone','coulomb']
for type in types:
# find maximum value for each determinant
max_dets = {}
for g in groups:
for d in g.determinants[type]:
# update max dets
if d.group not in max_dets.keys():
max_dets[d.group] = d.value
else:
max_dets[d.group] = max(d.value, max_dets[d.group], key= lambda v: abs(v))
# overwrite/add maximum value for each determinant
for det_group in max_dets.keys():
new_determinant = Source.determinant.Determinant(det_group, max_dets[det_group])
for g in groups:
g.set_determinant(new_determinant,type)
return
def get_coupled_systems(self, groups, get_coupled_groups):
""" This generator will yield one covalently coupled system at the time """
groups = set(groups)
while len(groups)>0:
# extract a system of coupled groups ...
system = set()
self.get_a_coupled_system_of_groups(groups.pop(), system, get_coupled_groups)
# ... and remove them from the list
groups -= system
yield system
return
def get_a_coupled_system_of_groups(self, new_group, coupled_groups, get_coupled_groups):
coupled_groups.add(new_group)
[self.get_a_coupled_system_of_groups(c, coupled_groups, get_coupled_groups) for c in get_coupled_groups(new_group) if c not in coupled_groups]
return
#
# Energy/summary-related methods
#
def calculate_folding_energy(self, pH=None, reference=None):
ddg = 0.0
for group in self.groups:
#print('Folding energy for %s at pH %f: %f'%(group,pH,group.calculate_folding_energy(self.parameters, pH=pH, reference=reference)))
ddg += group.calculate_folding_energy(self.parameters, pH=pH, reference=reference)
return ddg
def calculate_charge(self, parmaeters, pH=None):
unfolded = folded = 0.0
for group in self.get_titratable_groups():
unfolded += group.calculate_charge(parmaeters, pH=pH, state='unfolded')
folded += group.calculate_charge(parmaeters, pH=pH, state='folded')
return unfolded,folded
#
# conformation/bookkeeping/atom methods
#
def get_backbone_groups(self):
""" returns all backbone groups needed for the pKa calculations """
return [group for group in self.groups if 'BB' in group.type]
def get_sidechain_groups(self):
""" returns all sidechain groups needed for the pKa calculations """
return [group for group in self.groups if ('BB' not in group.type\
and not group.atom.cysteine_bridge)]
def get_covalently_coupled_groups(self):
return [g for g in self.groups if len(g.covalently_coupled_groups)>0]
def get_non_covalently_coupled_groups(self):
return [g for g in self.groups if len(g.non_covalently_coupled_groups)>0]
def get_backbone_NH_groups(self):
""" returns all NH backbone groups needed for the pKa calculations """
return [group for group in self.groups if group.type == 'BBN']
def get_backbone_CO_groups(self):
""" returns all CO backbone groups needed for the pKa calculations """
return [group for group in self.groups if group.type == 'BBC']
def get_groups_in_residue(self, residue):
return [group for group in self.groups if group.residue_type == residue]
def get_titratable_groups(self):
return [group for group in self.groups if group.titratable]
def get_titratable_groups_and_cysteine_bridges(self):
return [group for group in self.groups if group.titratable or group.residue_type == 'CYS']
def get_acids(self):
return [group for group in self.groups if (group.residue_type in self.parameters.acid_list
and not group.atom.cysteine_bridge)]
def get_backbone_reorganisation_groups(self):
return [group for group in self.groups if (group.residue_type in self.parameters.backbone_reorganisation_list
and not group.atom.cysteine_bridge)]
def get_ions(self):
return [group for group in self.groups if group.residue_type in self.parameters.ions.keys()]
def get_group_names(self, list):
return [group for group in self.groups if group.type in list]
def get_ligand_atoms(self):
return [atom for atom in self.atoms if atom.type=='hetatm']
def get_heavy_ligand_atoms(self):
return [atom for atom in self.atoms if atom.type=='hetatm' and atom.element != 'H']
def get_chain(self,chain):
return [atom for atom in self.atoms if atom.chainID != chain]
def add_atom(self, atom):
#print(self,'adding',atom)
self.atoms.append(atom)
if not atom.conformation_container:
atom.conformation_container = self
if not atom.molecular_container:
atom.molecular_container = self.molecular_container
# store chain id for bookkeeping
if not atom.chainID in self.chains:
self.chains.append(atom.chainID)
return
def copy_atom(self, atom):
new_atom = atom.makeCopy()
self.atoms.append(new_atom)
new_atom.conformation_container = self
return
def get_non_hydrogen_atoms(self):
return [atom for atom in self.atoms if atom.element!='H']
def top_up(self, other):
""" Tops up self with all atoms found in other but not in self """
for atom in other.atoms:
if not self.have_atom(atom):
self.copy_atom(atom)
return
def have_atom(self, atom):
res = False
for a in self.atoms:
if a.residue_label == atom.residue_label:
res = True
break
return res
def find_group(self, group):
for g in self.groups:
if g.atom.residue_label == group.atom.residue_label:
if g.type == group.type:
return g
return False
def set_ligand_atom_names(self):
for atom in self.get_ligand_atoms():
Source.ligand.assign_sybyl_type(atom)
return
def __str__(self):
return'Conformation container %s with %d atoms and %d groups'%(self.name,len(self),len(self.groups))
def __len__(self):
return len(self.atoms)
def sort_atoms(self):
# sort the atoms ...
self.atoms.sort(key=self.sort_atoms_key)
# ... and re-number them
for i in range(len(self.atoms)):
self.atoms[i].numb = i+1
return
def sort_atoms_key(self, atom):
key = ord(atom.chainID)*1e7
key += atom.resNumb*1000
if len(atom.name) > len(atom.element):
key += ord(atom.name[len(atom.element)])
#print(atom,ord(atom.name[len(atom.element)]), '|%s||%s|'%(atom.name,atom.element))
return key