def get_dssp_info(PDB_file, model, dir):
"""Runs DSSP on protein input"""
#TODO : you can run DSSP through biopython. The output contains a lot of useful information.
#Tip : make sure your secondary structure indexing matches the sequence order in the PDB file!
return PDB.DSSP(model, dir + '/' + PDB_file, dssp='mkdssp')
def get_sasa(self, dssp_loc="/usr/bin/mkdssp", skip=None):
self.dssp_loc = dssp_loc
SASA = {}
protein = self.universe.selectAtoms("protein")
for ts in self.universe.trajectory:
if skip:
self.universe.trajectory.skip = skip
sys.stdout.flush()
sys.stdout.write('\rsasa [step {0}] '.format(
self.universe.trajectory.frame))
writer = MDAnalysis.Writer("tmp.pdb")
writer.write(protein)
writer.close()
parser = bp.PDBParser()
structure = parser.get_structure('tmp', 'tmp.pdb')
dssp = bp.DSSP(structure[0], 'tmp.pdb', self.dssp_loc)
for key in dssp.keys():
resnum = dssp[key][0]
sasa = dssp[key][2]
if resnum.id[1] in SASA:
SASA[resnum.id[1]].append(sasa)
else:
SASA[resnum.id[1]] = [sasa]
count = 0
fp = open(self.out_path + self.out_file + "_sasa.dat", 'w')
for key in SASA:
fp.write("{0}\t{1}\t{2}\t{3}\n".format(protein.resnames()[count],
key, np.mean(SASA[key]),
np.std(SASA[key], ddof=1)))
count += 1
fp.close()
sys.stdout.write('\rSASA table created ')
print
def run_dssp(self):
pdb = PDB.PDBList()
pdb.retrieve_pdb_file(self.pdb_code, pdir='./', file_format="pdb")
p = PDB.PDBParser()
f = 'pdb{}.ent'.format(self.pdb_code.lower())
wt_residues = [
i for i in Residue.objects.filter(
protein_conformation__protein=self.protein).exclude(
protein_segment__slug__in=['N-term', 'C-term'])
]
gn_residues = [
i.sequence_number for i in wt_residues if i.generic_number
and i.protein_segment.slug not in ['ECL1', 'ECL2', 'ICL3', 'ECL3']
]
structure = p.get_structure(self.pdb_code, f)
for chain in structure[0]:
ch = chain.get_id()
self.chains.append(ch)
self.dssp_dict[ch] = OrderedDict()
self.dssp_info[ch] = OrderedDict([('H', 0), ('B', 0), ('E', 0),
('G', 0), ('I', 0), ('T', 0),
('S', 0), ('-', 0)])
if len(self.dssp_dict) > 1:
dssp = PDB.DSSP(structure[0], f, dssp='/env/bin/dssp')
for key in dssp.keys():
if int(key[1][1]) in gn_residues:
self.dssp_dict[key[0]][key[1][1]] = dssp[key]
self.dssp_info[key[0]][dssp[key][2]] = self.dssp_info[
key[0]][dssp[key][2]] + 1
os.remove(f)
def runDssp(self):
"""Run DSSP executable for this model"""
if (self.dssp is None):
dssp = PDB.DSSP(self.bioModel, self.pcssRunner.pdh.getFullModelFile(self),
self.pcssRunner.internalConfig["dssp_executable"])
#Hard to get exact reason why DSSP didn't work since it's BioPython, but will set
#as feature exception rather than global exception
if (dssp is None or len(dssp.keys()) < 1):
raise pcssErrors.DsspException("Did not load DSSP for model %s. This likely indicates a problem with the "
"Biopython DSSP module;\ntry running DSSP from the command line to isolate "
"the issue" % self.getId())
self.dssp = dssp
def secondary_structure(pdb_file, pdb_code):
parser = biop.PDBParser()
structure = parser.get_structure(pdb_code, pdb_file)
model = structure[0]
dssp = biop.DSSP(model, pdb_file)
return {
'helix': [np.array(np.where(np.array(dssp)[:, 2] == 'H')) + 1][0][0],
'strand': [np.array(np.where(np.array(dssp)[:, 2] == 'E')) + 1][0][0],
'pi_helix':
[np.array(np.where(np.array(dssp)[:, 2] == 'I')) + 1][0][0],
'turn': [np.array(np.where(np.array(dssp)[:, 2] == 'T')) + 1][0][0],
'bend': [np.array(np.where(np.array(dssp)[:, 2] == 'S')) + 1][0][0],
}
def get_first_residue_id_dssp(pdbname, pdbpath, pdb_id):
''' get id of first residue in pdb file (pdb numbering) '''
''' use dssp data where pdb ids are keys of dssp data dictionary '''
''' input: pdbname, path to pdb file, pdb id with chain, example input: 'pdb1ztm', '/home/pdb/1ztm.pdb', '1ztm_A' '''
''' output: integer id of first residue in pdb, example output: 44 '''
p = PDB.PDBParser()
structure = p.get_structure(pdbname, pdbpath)
model = structure[0]
dssp = PDB.DSSP(model, pdbpath)
chain_id = pdb_id.split('_')[-1] # fetch chain id from pdb_id
chain_data = []
for res in list(dssp.keys()):
# consider only residues of desired chain
if res[0] == chain_id:
chain_data.append(res)
return chain_data[0][1][1]
def assign_secondary_structure(pdbfile, modelno=0):
"""
Uses DSSP via Biopython to assign secondary structure.
Requires DSSP to be installed.
--PARAMETERS--
pdbfile: the path to the structure (in PDB format) for which you wish to
get secondary structure assignments.
modelno: specify which model in the PDB file should be analysed. Default is
the first.
--RETURNS--
A dictionary containing secondary structure assignments, using DSSP codes
(i.e. E = beta strand, H = alpha helix, etc.). Dictionary keys are the
protein chain IDs, and values are a list of tuples giving residue
ss assignments: (resid, ss_assignment)
"""
# Load structure using Biopython and select specified model
structure = PDB.PDBParser(QUIET=True).get_structure("structure", pdbfile)
model = structure[modelno]
# Run DSSP
dssp_result = PDB.DSSP(model, pdbfile)
# Extract SS assignments
# List of tuples format maintains the correct residue order
result = {}
for chain, res in dssp_result.keys():
if chain not in result:
result[chain] = []
resid = biopython_resid_to_str(res)
k = (chain, res)
result[chain].append((resid, dssp_result[k][1], dssp_result[k][2]))
return result
def rawChainParser(filepath, chainID, pssm):
parser = PDB.PDBParser()
structure = parser.get_structure(chainID, filepath)
model = structure[0]
d = PDB.DSSP(model, filepath)
rd = ResidueDepth(model)
pharmDic = getPharmacophoreDict()
hs = PDB.HSExposure.HSExposureCA(model)
df = pd.DataFrame()
for residue in model[chainID]:
seqID = getSeqIndex(residue)
row = {}
x, y, z = getResCoords(residue)
resName = residue.get_resname()
row["AA"] = PDB.Polypeptide.three_to_one(resName)
row["x"] = x[0]
row["y"] = y[0]
row["z"] = z[0]
tupKey = (chainID, (' ', seqID, ' '))
row["res_depth"] = rd[tupKey][0]
row["ca_depth"] = rd[tupKey][1]
dssp = d[(chainID, seqID)]
row["ss"] = dssp[2]
row["asa"] = dssp[3]
row["phi"] = dssp[4] / 360.0
row["psi"] = dssp[5] / 360.0
if tupKey in hs:
row["hseu"] = hs[tupKey][0]
row["hsed"] = hs[tupKey][1]
else: #NO HSE CALCULATED
row["hseu"] = 0
row["hsed"] = 0
row["seqId"] = seqID - 1
#row["bFactor"] = centralAtom.get_bfactor() #must be done using zhang lab tool resQ instead
#get pssm row
pssmRow = pssm[seqID - 1]
row["aligns"] = sum(pssmRow.values()) # total alignments
if (row["aligns"] != 0):
for key in pssmRow.keys():
if key not in list('ABCDEFGHIKLMNPQRSTUVWYZ'):
print(key)
row["pssm_" + key] = pssmRow[key] / row["aligns"]
if (residue.is_disordered()):
print(f"disorded atom in res {getSeqIndex()}")
row.update(pharmDic[row["AA"]])
df = df.append(row, ignore_index=True)
#check for missed columns in pssm
for a in 'ABCDEFGHIKLMNPQRSTUVWYZ': # check for missing aas
if ("pssm_" + a) not in df:
df["pssm_" + a] = 0.0
aaEncoder = AAonehot()
aaTransformed = aaEncoder.transform(df["AA"])
aaCols = ["AA_" + x for x in aaEncoder.classes_]
aaDf = pd.DataFrame(aaTransformed, columns=aaCols)
ssEncoder = ssOneHot()
ssTransformed = ssEncoder.transform(df["ss"])
ssCols = ["SS_" + x for x in ssEncoder.classes_]
ssDf = pd.DataFrame(ssTransformed, columns=ssCols)
#center coordinates
max = df.max()
min = df.min()
df["x"] = df["x"] - (max["x"] + min["x"]) / 2
df["y"] = df["y"] - (max["y"] + min["y"]) / 2
df["z"] = df["z"] - (max["z"] + min["z"]) / 2
df = pd.concat([df, aaDf, ssDf], axis=1).drop(["AA", "ss"], axis=1)
df = df.fillna(0.0)
if (df.shape[1] != 72):
print(df)
assert df.shape[
1] == 72, f"Incorrect pssmdf shape = {df.shape[1]} for file: {filepath}" #error check
#pd.set_option('display.max_columns', 500)
#print(df.describe())
return df
def add_dssp(self,selected_chains=list()):
'''
Adds DSSP features.
DSSP ignores hetatoms but treats oligomers as single units
This means that interface residues will have lower than expected SASA
Therefore, each chain is split into individual chains and DSSP is
calculated over each chain separately and over the whole oligomer
DSSP takes files directly so need to create a temporary PDB file for
each chain
'''
if self.debug:
print self.debug_head+"Adding DSSP"
print self.debug_head+"Current header: {}".format(self.header)
if self.id == "Holder":
c = HOLDERS.keys()
h = ['?','?','?']+[HOLDERS[x] for x in c]
c = self.res_header+c
self.dssp = pd.DataFrame([h],columns=c)[self.res_header+HEADERS['dssp']]
if self.debug:
print self.debug_head+"added holder: {}".format(h)
else:
genempty = False
dssp = list()
try:
#Calculate DSSP for Oligomer
#DSSP is pain in that it only takes files. Therefore, if this was created
# using a model or url, create a temporary file
if self.debug:
print self.debug_head+"Oligomer DSSP"
if self.filename == "url" or self.filename == "model":
ofile = "_".join([uuid.uuid4().hex,self.id])
io = PDB.PDBIO()
io.set_structure(self.struct)
io.save(ofile)
if self.debug:
print self.debug_head+"wrote file for dssp"
try:
oligomer = dict(PDB.DSSP(self.struct[0],ofile,self.dssp_path))
except Exception as e: # DSSP failures generate unnamed exceptions
raise DescriptorException("dssp calculation",e)
os.remove(ofile)
else:
oligomer = dict(PDB.DSSP(self.struct[0],self.filename,self.dssp_path))
if self.debug:
print self.debug_head+"finished oligomer DSSP"
class chain_select(PDB.Select): #Needed for extracting each chain
def accept_chain(self,c):
if c.get_id() == chainid:
return True
else:
return False
#Calculate DSSP for isolated chains
isolated = dict()
badchains = list()
if len(self.struct[0].get_list()) == 1:
if self.debug:
print self.debug_head+"Single chain, no need to run DSSP on isolated chains"
isolated[self.struct[0].get_list()[0].get_id()] = oligomer
else:
if self.debug:
print self.debug_head+"Running DSSP on isolated chains"
io = PDB.PDBIO()
io.set_structure(self.struct)
for chain in self.struct[0]:
# Make sure there are residues in this chain otherwise unnamed Exception
if len([x for x in chain.get_residues() if x.get_id()[0]==' ' and len(x)>2])==0:
badchains.append(chain.get_id())
if self.debug:
print self.debug_head+"skipping no-res chain {}".format(chain.get_id())
continue
# Generate random filename
chainid = chain.get_id()
if chainid not in selected_chains:
if self.debug:
print self.debug_head+"skipping unwanted chain {}".format(chainid)
continue
cfile = "_".join([uuid.uuid4().hex,self.id,chainid])
# Write isolated chain to random filename
# Then calculate DSSP from it
io.save(cfile, chain_select())
tmp = self.parser.get_structure(chainid,cfile)
if self.debug:
print self.debug_head+"write file for chain {}, calculating DSSP".format(chainid)
try:
isolated[chainid] = dict(PDB.DSSP(tmp[0],cfile,self.dssp_path))
except Exception: # DSSP failures generate unnamed exceptions
print "Warning, DSSP failed for {} isolated chain {}, setting equal to oligomer".format(self.id,chainid)
isolated[chainid] = oligomer
os.remove(cfile)
#Generate DSSP DataFrame
if self.debug:
print self.debug_head+"generating DSSP dataframe"
if len(badchains)>0:
print self.debug_head+"skipping badchains {}".format(badchains)
for res in oligomer:
if res[1][0]!=" ": continue
c = res[0]
if c not in selected_chains or c in badchains: continue
# try:
# r = int(res[1][1])
# except ValueError:
# r = -999
r = res[1][1]
i = res[1][2]
ss = oligomer[res][2]
try:
sasa = round(float(oligomer[res][3]),3)
isosasa = round(float(isolated[c][res][3]),3)
except ValueError: #TODO: Does this every happen?
sasa = oligomer[res]
isosasa = isolated[c][res][3]
dssp.append([c,r,i,ss,sasa,isosasa])
except (OSError,DescriptorException,PDB.PDBExceptions.PDBException) as e: # Generate a holder set on the fly
print "Warning, DSSP calculation failed for {}: {}".format(self.id,e)
genempty = True
# raise ParseWarning("DSSP Calculation","Failed DSSP for {}({})".format(self.id,e))
# except ParseWarning as e:
if self.debug:
print self.debug_head+"DSSP failed with exception {}".format(e)
if len(dssp)==0: # Generate a holder set on the fly if it's still empty
genempty = True
if self.debug:
print self.debug_head+"DSSP set is empty, generating holder set"
if genempty:
dssp = list()
for c in self.struct[0]:
for r in c:
res = r.get_id()
if res[0]!=' ': continue
dssp.append([c.get_id(),res[1],res[2],'?',-999,-999])
self.dssp = pd.DataFrame(dssp,columns=self.res_header+HEADERS['dssp'])
if self.debug:
print "Finished dssp datatable has {} rows".format(len(self.dssp.index))
if self.descriptors is None:
self.descriptors = self.dssp
else:
self.descriptors = self.descriptors.merge(self.dssp,
on=self.res_header,
how='outer')
self.header += HEADERS['dssp']
if self.debug:
print self.debug_head+"Finished DSSP, current header: {}".format(self.header)
HSEA_dict = HSEA.property_dict
HSEA_keys = HSEA.property_keys
HSEA_list = HSEA.property_list
HSEB = PDB.HSExposureCB(s)
HSEB_dict = HSEB.property_dict
HSEB_keys = HSEB.property_keys
HSEB_list = HSEB.property_list
depth = PDB.ResidueDepth(s)
dep_dict = depth.property_dict
dep_keys = depth.property_keys
dep_list = depth.property_list
dssp = PDB.DSSP(s, "3skpFH.pdb")
dssp_dict = dssp.property_dict
nb_dict = {}
nb = PDB.NeighborSearch(ca_list)
for a in ca_list:
t = nb.search(a.get_coord(), 8)
aa = a.get_parent()
aa_id = (aa.get_parent().get_id(), aa.get_id())
nb_dict[aa_id] = t
dic = {}
dic["res_id"] = []
for a in aa_list:
dic["res_id"].append(a.get_id())
def get_dssp_df(model, pdb_file, outfile=None, outdir=None, outext='_dssp.df', force_rerun=False):
"""
Args:
model:
pdb_file:
outfile:
outdir:
outext:
force_rerun:
Returns:
"""
# Create the output file name
outfile = ssbio.utils.outfile_maker(inname=pdb_file, outname=outfile, outdir=outdir, outext=outext)
if ssbio.utils.force_rerun(flag=force_rerun, outfile=outfile):
try:
# TODO: errors with non-standard residues, ie. MSE in 4Q6U or 1nfr
# TODO: write command line executor for DSSP and parser for raw DSSP results
dssp = PDB.DSSP(model, pdb_file)
except KeyError:
return pd.DataFrame()
if len(dssp.property_list) == 0:
return pd.DataFrame()
# Reorganize the results into a csv file
appender = []
for k in dssp.property_keys:
to_append = []
x = dssp.property_dict[k]
chain = k[0]
residue = k[1]
het = residue[0]
resnum = residue[1]
icode = residue[2]
to_append.extend([chain, resnum, icode])
to_append.extend(x)
appender.append(to_append)
cols = ['chain', 'resnum', 'icode',
'dssp_index', 'aa', 'ss', 'exposure_rsa', 'phi', 'psi',
'NH_O_1_relidx', 'NH_O_1_energy', 'O_NH_1_relidx',
'O_NH_1_energy', 'NH_O_2_relidx', 'NH_O_2_energy',
'O_NH_2_relidx', 'O_NH_2_energy']
df = pd.DataFrame.from_records(appender, columns=cols)
# Adding additional columns
df = df[df['aa'].isin(list(aa1))]
df['aa_three'] = df['aa'].apply(one_to_three)
df['max_acc'] = df['aa_three'].map(residue_max_acc['Sander'].get)
df[['exposure_rsa', 'max_acc']] = df[['exposure_rsa', 'max_acc']].astype(float)
df['exposure_asa'] = df['exposure_rsa'] * df['max_acc']
df.to_csv(outfile)
else:
log.debug('{}: already ran DSSP and force_rerun={}, loading results'.format(outfile, force_rerun))
df = pd.read_csv(outfile, index_col=0)
return df
def get_sasa(topology, trajectory, dssp_loc=master_dssp_location, skip=None):
"""
This function currently only works with one or two chains, because I am lazy.
"""
dssp_loc = dssp_loc
DSSP = {'A': {}}
universe = MDAnalysis.Universe(topology, trajectory)
#set the chain name here. this will only work for MDAnalysis 0.16
chain_name = universe.add_Segment(segid='A')
universe.residues[...].segments = chain_name
protein = universe.select_atoms("protein")
diff_res = []
#this attempt to identify chain breaks will only work if the resids
#... in the chains are not numbered consecutively
for i in range(len(protein.resnums)):
if protein.resnums[i] - protein.resnums[i - 1] < 0 and i != 0:
diff_res.append(i)
if len(diff_res) >= 1:
chain_sep = diff_res.pop(0)
chain_end = len(protein.resnums)
bchain = protein[chain_sep:chain_end]
bchain.set_segids('B')
DSSP['B'] = {}
for ts in universe.trajectory:
if skip:
universe.trajectory.skip = skip
sys.stdout.flush()
sys.stdout.write('\rsasa [step {0}] '.format(
universe.trajectory.frame))
writer = MDAnalysis.Writer("tmp.pdb")
writer.write(protein)
writer.close()
parser = bp.PDBParser()
structure = parser.get_structure('tmp', 'tmp.pdb')
dssp = bp.DSSP(structure[0], 'tmp.pdb', dssp_loc)
for key in dssp.keys():
if 0:
resobj = dssp[key][0]
resname = dssp[key][0].resname
residx = resobj.id[1]
chain = key[0]
secondary_structure = resobj.xtra['SS_DSSP']
rel_sasa = resobj.xtra['EXP_DSSP_RASA']
abs_sasa = resobj.xtra['EXP_DSSP_ASA']
phi = resobj.xtra['PHI_DSSP']
psi = resobj.xtra['PSI_DSSP']
resobj = dssp[key]
resname = residue_codes_reverse[resobj[1]]
residx = key[1][1]
chain = key[0]
secondary_structure = resobj[2]
rel_sasa = resobj[3]
abs_sasa = resobj[3] * dssp.residue_max_acc[resname]
phi = resobj[4]
psi = resobj[5]
if residx in DSSP[chain] and DSSP[chain][residx][
'resname'] == resname:
DSSP[chain][residx]['dssp'].append(secondary_structure)
DSSP[chain][residx]['rel_sasa'].append(rel_sasa)
DSSP[chain][residx]['abs_sasa'].append(abs_sasa)
DSSP[chain][residx]['phi'].append(phi)
DSSP[chain][residx]['psi'].append(psi)
DSSP[chain][residx]['time'].append(ts.time)
else:
DSSP[chain][residx] = {
'dssp': [secondary_structure],
'phi': [phi],
'time': [ts.time],
'psi': [psi],
'rel_sasa': [rel_sasa],
'chain': chain,
'abs_sasa': [abs_sasa],
'resname': resname
}
return DSSP
pdb_file = "{}/{}.pdb".format(PDB_HOME, pdb_id.lower())
pdbIO = PDB.PDBIO()
pdbIO.set_structure(structure[0])
pdbIO.save(pdb_file)
#------------------------------------------------------------------------------
# Get Surface residue
# https://biopython.org/wiki/The_Biopython_Structural_Bioinformatics_FAQ
# https://biopython.org/DIST/docs/api/Bio.PDB.DSSP%27-module.html
# Download and Install DSSP is required
# ftp://ftp.cmbi.ru.nl//pub/molbio/software/dssp-2/
#------------------------------------------------------------------------------
# Read PDB
#pdb_file = '/Users/jjeong/local/project_dev/ppi/codes/utils/1A2Y.pdb'
# load structure
pdbParser = PDB.PDBParser()
structure = pdbParser.get_structure(pdb_id, pdb_file)
model = structure[0]
#dssp = PDB.DSSP(model=model, in_file="/Users/jjeong/local/project_dev/ppi/outputs/pdb/6dm0.dssp", file_type='DSSP')
dssp = PDB.DSSP(model=model,
in_file=pdb_file,
dssp='mkdssp',
acc_array='Sander',
file_type='PDB')
#-- To see Max ACC
maxAcc = dssp.residue_max_acc
print(hsspProfile)
import glob
from Bio import PDB
pdb_files = glob.iglob('all_pdbs/*')
file = open('casp11.sec', 'w')
c = 0
for pdb in pdb_files:
c += 1
print(c)
p = PDB.PDBParser()
structure = p.get_structure(pdb[:-4], pdb)
model = structure[0]
dssp = PDB.DSSP(model, pdb)
seq = ''
ss = ''
for key in list(dssp.keys()):
ss += dssp[key][2]
seq += dssp[key][1]
file.write('>{}\n'.format(pdb))
file.write('{}\n'.format(seq))
file.write('>{}\n'.format(pdb))
file.write('{}\n'.format(ss))
file.close()