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gc.py
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gc.py
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#!/usr/bin/env python
from __future__ import division
import sys, os, math, cPickle, random
import multiprocessing
from pyRMSD import RMSDCalculator
from scipy.spatial.distance import squareform
import numpy as np
from sklearn.cluster import MeanShift
from sklearn import manifold
import heapq
import itertools
from Bio import PDB
from Bio.SVDSuperimposer import SVDSuperimposer
import warnings
class Options():
def __init__(self, bnd_dihedral, bnd_rmsd, support_dihedral, support_rmsd):
self.bnd_dihedral = bnd_dihedral
self.bnd_rmsd = bnd_rmsd
self.support_dihedral = support_dihedral # in percent of the pool
self.support_rmsd = support_rmsd
class Work():
def __init__(self, pdb_path, scores_file, n_sym = 1):
self.pdb_path = pdb_path
self.scores_file = scores_file
self.n_sym = n_sym
self.pdb_files = os.listdir(self.pdb_path)
self.pdb_files = [f for f in self.pdb_files if f.endswith(".pdb")]
self.pdb_files.sort()
self.n_models = len(self.pdb_files)
parsed_file_name = self.pdb_path+"_parsed.pkl"
if os.path.isfile(parsed_file_name):
self.CA, self.DIH = cPickle.load(open(parsed_file_name, "rb"))
else:
self.CA, self.DIH = self.parse_structures()
cPickle.dump((self.CA, self.DIH), open(parsed_file_name, "wb"))
self.n_res = self.DIH.shape[1]
if self.scores_file != "":
self.scores = []
scores_txt = open(self.scores_file, "rb").readlines()
for line in scores_txt[1:]:
line_arr = line.split()
score = float(line_arr[1])
if score > 0:
score = -1
self.scores.append(score)
assert len(self.scores) == len(self.pdb_files)
self.use_scores = True
else:
self.use_scores = False
def parse_structures(self):
phipsi_list = []
ca_all = []
warnings.filterwarnings("ignore")
for pdb_file in self.pdb_files:
print "Parsing", pdb_file
structure = PDB.PDBParser().get_structure(pdb_file, os.path.join(self.pdb_path,pdb_file))
model = structure[0]
phipsi = []
ca_list = []
for chain in model.child_list:
polypeptide = PDB.PPBuilder().build_peptides(chain)[0]
phipsi = phipsi + polypeptide.get_phi_psi_list()
for residue in chain:
atom = residue['CA']
ca_list.append(atom.coord)
phipsi_list.append(phipsi)
ca_all.append(ca_list)
n_res_total = len(phipsi_list[0])
DIH = np.zeros((self.n_models, n_res_total, 2))
CA = np.zeros((self.n_models, n_res_total, 3))
for i,(phipsi,model) in enumerate(zip(phipsi_list,ca_all)):
for j,(angle,ca_atom) in enumerate(zip(phipsi,model)):
DIH[i, j, :] = angle[:]
CA[i,j,:] = ca_atom
return CA, DIH
def align_models(CA):
n_models = CA.shape[0]
working_CA = np.copy(CA)
sup=SVDSuperimposer()
ref_model = working_CA[0, :, :]
rms_total = 0
for i_model in range(1, n_models):
sup.set(ref_model, working_CA[i_model])
sup.run()
rms_total += sup.get_rms()**2
working_CA[i_model] = sup.get_transformed()
rms_best = float("inf")
epsilon = 0.001
while rms_best - rms_total > epsilon:
rms_best = rms_total
mean_model = np.mean(working_CA,0)
rms_total = 0
for i_model in range(n_models):
sup.set(mean_model, working_CA[i_model])
sup.run()
rms_total += sup.get_rms()**2
working_CA[i_model] = sup.get_transformed()
transformations = []
for start_model, result_model in zip(CA, working_CA):
sup.set(result_model, start_model)
sup.run()
transformations.append(sup.get_rotran())
return transformations,np.sqrt(rms_total/n_models)
def distance_matrix(CA):
n_models = CA.shape[0]
distances = np.zeros((n_models, n_models))
sup=SVDSuperimposer()
for i in range(n_models):
model1 = CA[i,:,:]
for j in range(i+1,n_models):
model2 = CA[j,:,:]
sup.set(model1, model2)
sup.run()
rms=sup.get_rms()
distances[i,j] = rms
distances[j,i] = rms
return distances
def distance_matrix_BC(CA):
n_models = CA.shape[0]
distances = np.zeros((n_models, n_models))
centered_X_all = []
det_XX_all = []
for i in range(n_models):
model_orig = CA[i,:,:]
mean_v = np.mean(model_orig,0)
model_centered = model_orig - mean_v
det_XX = np.linalg.det(np.dot(np.transpose(model_centered), model_centered))
centered_X_all.append(model_centered)
det_XX_all.append(det_XX)
for i in range(n_models):
model1 = np.transpose(centered_X_all[i])
for j in range(i+1,n_models):
det_XY = np.linalg.det(np.dot(model1, centered_X_all[j]))
BC = 1-det_XY/math.sqrt(det_XX_all[i]*det_XX_all[j])
distances[i,j] = BC
distances[j,i] = BC
return distances
def out_ensemble(work, ens, levels, prefix):
warnings.filterwarnings("ignore")
score,residues,support = ens
if len(support)>10:
support=support[:10]
aln_CA = work.CA.take(support, 0).take(residues, 1)
transformations,rms = align_models(aln_CA)
ens_structure = PDB.Structure.Structure(" ")
ens_name = prefix+"_{0:03d}_{1:03d}_{2:03d}_{3:02.2f}".format(min(residues), max(residues), len(residues), rms)
ala_atom_names = {"N", "CA", "C", "O", "CB"}
bfac_base = 10
for file_ind in support:
file_name = work.pdb_files[file_ind]
structure=PDB.PDBParser().get_structure(file_name, os.path.join(work.pdb_path,file_name))
model = structure.child_list[0]
new_model = PDB.Model.Model(len(ens_structure)+1)
offset = 0
for chain in model.child_list:
offset_next = len(chain.child_list)
for res_ind,residue in reversed(list(enumerate(chain))):
if res_ind+offset not in residues:
id = residue.id
chain.detach_child(id)
else:
bfac_mult = [i for i in range(len(levels)) if res_ind+offset in levels[i]][0]
for atom in reversed(residue.child_list):
if atom.get_name() not in ala_atom_names:
residue.detach_child(atom.id)
else:
atom.set_bfactor(bfac_base*bfac_mult)
offset += offset_next
new_model.add(chain)
ens_structure.add(new_model)
for aln_structure, rotran in zip(ens_structure.child_list, transformations):
atom_list = aln_structure.get_atoms()
for atom in atom_list:
atom.transform(rotran[0].astype('f'), rotran[1].astype('f'))
io=PDB.PDBIO()
io.set_structure(ens_structure)
io.save(ens_name+".pdb")
def evaluate_candidate(options, work, top_frag, candidate):
combined = []
top_score,top_ind,top_support = top_frag
cand_score,cand_ind,cand_support = candidate
min_support = options.support_rmsd
comb_ind = sorted(list(set(top_ind) | set(cand_ind)))
comb_support = sorted(list(set(top_support) & set(cand_support)))
n_comb_support=len(comb_support)
if n_comb_support < min_support:
return []
if work.use_scores:
comb_scores = [work.scores[i] for i in comb_support]
aln_models = work.CA.take(comb_support, 0).take(comb_ind, 1)
calculator = RMSDCalculator.RMSDCalculator("QCP_OMP_CALCULATOR", aln_models)
dist = squareform(calculator.pairwiseRMSDMatrix())
mds = manifold.MDS(n_components=2, dissimilarity="precomputed", n_jobs=1, n_init = 5)
pos = mds.fit(dist).embedding_
try:
ms = MeanShift(bandwidth=options.bnd_rmsd, cluster_all=False, bin_seeding=True, min_bin_freq = min_support)
ms.fit(pos)
except:
try:
ms = MeanShift(bandwidth=options.bnd_rmsd, cluster_all=False, bin_seeding=False)
ms.fit(pos)
except:
return []
labels = ms.labels_
labels_unique = np.unique(labels)
for label in labels_unique:
if label == -1:
continue
class_members = [index[0] for index in np.argwhere(labels == label)]
class_support = [comb_support[i] for i in class_members]
n_class_support = len(class_support)
if n_class_support < min_support:
continue
class_dist = dist.take(class_members,0).take(class_members,1)
mean_dist = np.mean(squareform(class_dist))
if work.use_scores:
class_scores = [comb_scores[i] for i in class_members]
class_score = sum(class_scores)/(1+mean_dist)
else:
class_score = (-n_class_support)/(1+mean_dist)
heapq.heappush(combined, (class_score, comb_ind, class_support))
if combined:
return heapq.heappop(combined)
return []
def double_peptides(options, work, peptides):
n_peptide = len(peptides[0][1])*2
peptides_out=[]
min_support_seeds = int(work.n_models*options.support_dihedral)
for res_ind in range(work.n_res-n_peptide+1):
indices = [range(res_ind,res_ind+int(n_peptide/2)), range(res_ind+int(n_peptide/2),res_ind+n_peptide)]
peptide_collection = []
for ind in indices:
singletons_ind = [residue for residue in peptides if residue[1] == ind]
peptide_collection.append(singletons_ind)
peptide_candidates = itertools.product(*peptide_collection)
for peptide in peptide_candidates:
singles_support = [set(residue[2]) for residue in peptide]
peptide_support = list(set.intersection(*singles_support))
n_peptide_support = len(peptide_support)
if n_peptide_support >= min_support_seeds:
indices_flat = [item for sublist in indices for item in sublist]
heapq.heappush(peptides_out, (-n_peptide_support, indices_flat, sorted(peptide_support)))
return peptides_out
def grow_seed(args):
options, work, all_peptides, seed = args
n_level = len(all_peptides) - 2
seed_score, seed_ind, seed_support = seed
growing = (seed_score, seed_ind, seed_support)
is_growing = True
cur_peptides = all_peptides[n_level]
bfac_level = [set(seed_ind)]
while is_growing:
combined = []
for candidate in cur_peptides:
if set(candidate[1]) & set(growing[1]):
continue
cand_ev = evaluate_candidate(options, work, growing, candidate)
if cand_ev != []:
heapq.heappush(combined, cand_ev)
if combined != []:
prev_ind = set(growing[1])
growing = heapq.heappop(combined)
next_ind = set(growing[1])
bfac_level.append(set.difference(next_ind,prev_ind))
else:
n_level -= 1
if n_level == 0:
is_growing = False
else:
cur_peptides = all_peptides[n_level]
print "Finished seed", seed
print "Result:", growing
return growing,bfac_level
def run(options, work):
print 'Dihedral bandwidth:', options.bnd_dihedral
print 'RMSD bandwidth:', options.bnd_rmsd
singletons = []
min_bin_freq = options.support_rmsd
for res_ind in range(work.n_res):
distr_res = work.DIH[:,res_ind,:]
if distr_res[0,0] == None or distr_res[0,1] == None:
continue
try:
ms = MeanShift(bandwidth=options.bnd_dihedral, cluster_all=False, bin_seeding=True, min_bin_freq = min_bin_freq)
ms.fit(distr_res)
except:
try:
ms = MeanShift(bandwidth=options.bnd_dihedral, cluster_all=False, bin_seeding=False)
ms.fit(distr_res)
except:
continue
labels = ms.labels_
labels_unique = np.unique(labels)
for label in labels_unique:
if label == -1:
continue
class_members = [index[0] for index in np.argwhere(labels == label)]
singletons.append((-len(class_members), [res_ind], class_members))
print len(singletons), "singletons"
all_peptides = [singletons]
while len(all_peptides[-1]) > 0 and len(all_peptides) < 5:
doubled = double_peptides(options, work, all_peptides[-1])
print len(doubled), 2**len(all_peptides), "-peptides"
all_peptides.append(doubled)
if len(all_peptides[-1]) == 0:
all_peptides.pop()
seed_candidates = sorted(all_peptides[-1])
seeds = []
sym_offset = int(work.n_res/work.n_sym)
for seed_candidate in seed_candidates:
independent = True
cand_ind = set(seed_candidate[1])
cand_support = set(seed_candidate[2])
for seed in seeds:
seed_ind = set(seed[1])
seed_support = set(seed[2])
sim_ind = len(cand_ind & seed_ind)/len(cand_ind | seed_ind)
sim_support = len(cand_support & seed_support)/len(cand_support | seed_support)
if min(seed_ind) < min(cand_ind):
first_ind = set([i + sym_offset for i in seed_ind])
second_ind = cand_ind
else:
first_ind = set([i + sym_offset for i in cand_ind])
second_ind = seed_ind
sym_sim_ind = len(first_ind & second_ind)/len(first_ind | second_ind)
if (sim_ind > 0.5 or sym_sim_ind > 0.5) and sim_support > 0.5:
independent = False
break
if independent:
seeds.append(seed_candidate)
print len(seeds), "seeds from", 2**(len(all_peptides)-1), "-peptides"
n_proc = min(max(1, multiprocessing.cpu_count()), len(seeds))
pool = multiprocessing.Pool(n_proc)
work_seeds = itertools.product([options], [work], [all_peptides], seeds)
results = pool.map(grow_seed, work_seeds, 1)
pool.close()
pool.join()
# TODO: find pairs with most coverage
return results
if __name__ == "__main__":
options = Options(bnd_dihedral=1.2, bnd_rmsd=0.5, support_dihedral=0.1, support_rmsd=10)
scores_file = ""
if len(sys.argv) == 1:
print "Usage: gc <folder> [scores]"
sys.exit()
if len(sys.argv) == 3:
scores_file = sys.argv[2]
pdb_path = sys.argv[1]
results_path = pdb_path+"_clusters"
if not os.path.exists(results_path):
os.makedirs(results_path)
work = Work(pdb_path=pdb_path, scores_file=scores_file, n_sym=1)
results = run(options, work)
os.chdir(results_path)
work.pdb_path = os.path.join("..",work.pdb_path)
for ind,(fragment,levels) in enumerate(results):
out_ensemble(work, fragment,levels,str(ind).zfill(3))
os.chdir("..")