def get_qfac(protein_file, npc, res_num, q_fac_dict):
"""Fit and individual tensor to each model in the bundle and save each Q-factor into an universal dictionary"""
# Load the protein, load the npc
prot = protein.load_pdb(protein_file)
rawData = dataparse.read_pcs(npc)
qfactor_sep = {}
# Initialize metal instance for search and set the initial position
mStart = metal.Metal()
mStart.position = prot[0]['A'][res_num]['CA'].position
# Loop: for every model fit an individual tensor and store Q-factors and tensor components into a dict
for model in prot:
parsedData = prot.parse(rawData, models=model.id)
[mGuess], _ = fit.svd_gridsearch_fit_metal_from_pcs([mStart],
[parsedData],
radius=10,
points=10)
[mFit], [data] = fit.nlr_fit_metal_from_pcs([mGuess], [parsedData])
qfactor_sep[model.id] = fit.qfactor(data)
# Save in universal dictionary
if type(q_fact_dict[model.id]) == list:
q_fac_dict[model.id].append(fit.qfactor(data))
else:
q_fac_dict[model.id] = [fit.qfactor(data)]
minModel, minQfac = sorted(qfactor_sep.items(), key=lambda x: x[1])[0]
def get_tensor(protein_file, model, npc, res_num, tag_number):
"""Fit a tensor only to the specified model of the bundle pdb and writes down the corresponding components and
ORI"""
# Load the protein, load the npc
prot = protein.load_pdb(protein_file)
rawData = dataparse.read_pcs(npc)
# Initialize metal instance for search and set the initial position
mStart = metal.Metal()
mStart.position = prot[model]['A'][res_num]['CA'].position
# Get tensor on single structure
for mod in prot:
if mod.id == model:
parsedData = prot.parse(rawData, models=mod.id)
[mGuess], [data
] = fit.svd_gridsearch_fit_metal_from_pcs([mStart],
[parsedData],
radius=10,
points=10)
[mFit], [data] = fit.nlr_fit_metal_from_pcs([mGuess], [parsedData])
Axial = round(mFit.ax * 1E32, 3)
Rhombicity = round((mFit.rh / mFit.ax), 3)
# Generate .pcs metal center file
name = os.path.splitext(protein_file)[0] + "_metal_centers.pcs"
f = open(name, 'a+')
f.write(5 * " " + str(tag_number) + (14 - len(str(Axial))) * " " +
str(Axial) + "E+04 " + str(Rhombicity) + 5 * " " +
str(Tag_dictionary[tag_number]) + "\n")
# Extract information about the metal center position relative to the protein backbone and write them
ori = mFit.position
name_ori_upl = os.path.splitext(protein_file)[0] + "_ORI_UPL.upl"
name_ori_lol = os.path.splitext(protein_file)[0] + "_ORI_LOL.lol"
u = open(name_ori_upl, 'a+')
l = open(name_ori_lol, 'a+')
for res_num in Ori_dictionary[tag_number]:
res = prot[model]['A'][res_num]['CA'].position
res_type = prot[model]['A'][res_num].get_resname()
d = math.sqrt(((ori[0] - res[0])**2) + ((ori[1] - res[1])**2) +
((ori[2] - res[2])**2))
d_upl = round((d * 1E10) + 0.5, 2)
d_lol = round((d * 1E10) - 0.5, 2)
u.write((3 - len(str(res_num))) * " " + str(res_num) + " " + res_type +
" CA " + str(Tag_dictionary[tag_number]) + " ORI A0" +
(10 - len(str(d_upl))) * " " + str(d_upl) + "\n")
l.write((3 - len(str(res_num))) * " " + str(res_num) + " " + res_type +
" CA " + str(Tag_dictionary[tag_number]) + " ORI A0" +
(10 - len(str(d_lol))) * " " + str(d_lol) + "\n")
# Load the PCS data
rawData = dataparse.read_pcs('../data_files/calbindin_Er_HN_PCS_errors.npc')
# Associate PCS data with atoms of the PDB
parsedData = prot.parse(rawData)
# Define an initial tensor
mStart = metal.Metal()
# Set the starting position to an atom close to the metal
mStart.position = prot[0]['A'][56]['CA'].position
# Calculate an initial tensor from an SVD gridsearch
[mGuess], [data] = fit.svd_gridsearch_fit_metal_from_pcs([mStart],
[parsedData],
radius=10,
points=10)
# Refine the tensor using non-linear regression
[mFit], [data] = fit.nlr_fit_metal_from_pcs([mGuess], [parsedData])
# Estimate uncertainty sourcing noise from the models of the PDB
[mod_all], [mod_std] = fit.fit_error_models(fit.nlr_fit_metal_from_pcs,
initMetals=[mFit],
dataArrays=[parsedData])
mod_std.save('error_tensor_models.txt')
# Estimate uncertainty sourcing noise from experimental uncertainties
[mc_all], [mc_std] = fit.fit_error_monte_carlo(fit.nlr_fit_metal_from_pcs,
50,
for site in sites: # Loop over sites
bindingSite = int(re.search("\\d+", site).group()) # Get residue number
mStart = metal.Metal()
mStart.position = prot[0]['A'][bindingSite][
'CA'].position # Set strating position
hnpcss = []
# Assemble exp. PCS data for both ions
for ion in ions:
hnpcs_raw = dataparse.read_pcs(
"../data_files/IMP1_HN_{}_{}_FREE.npc".format(site, ion))
hnpcs = prot.parse(hnpcs_raw)
hnpcss.append(hnpcs)
# Fit the tensor by SVD, then NLR
mGuess, _ = fit.svd_gridsearch_fit_metal_from_pcs([mStart, mStart], hnpcss)
mFit, _ = fit.nlr_fit_metal_from_pcs(mGuess, hnpcss)
# Sample purturbed tensors by bootstrap
mSamples, mStd = fit.fit_error_bootstrap(fit.nlr_fit_metal_from_pcs,
BOOTSTRAP_ITER,
0.8,
initMetals=mFit,
dataArrays=hnpcss)
mdata.append(mSamples)
for ion, mSamples in zip(ions, zip(*mdata)):
trpdata = []
mdata = []
# Loop sites with fitted tensors
rawData3 = dataparse.read_pcs('../data_files/calbindin_Yb_HN_PCS.npc')
# Associate PCS data with atoms of the PDB
parsedData = []
for rd in [rawData1, rawData2, rawData3]:
parsedData.append(prot.parse(rd))
# Make a list of starting tensors
mStart = [metal.Metal(), metal.Metal(), metal.Metal()]
# Set the starting position to an atom close to the metal
mStart[0].position = prot[0]['A'][56]['CA'].position
# Calculate initial tensors from an SVD gridsearch
mGuess = fit.svd_gridsearch_fit_metal_from_pcs(mStart,
parsedData,
radius=10,
points=10)
# Refine the tensors using non-linear regression
fitParameters = ['x', 'y', 'z', 'ax', 'rh', 'a', 'b', 'g']
mFit = fit.nlr_fit_metal_from_pcs(mGuess, parsedData, fitParameters)
# Save the fitted tensors to files
for name, metal in zip(['Tb', 'Er', 'Yb'], mFit):
metal.save("tensor_{}.txt".format(name))
# Make experimental and calculated PCS lists
exp = []
cal = []
for metal, data in zip(mFit, parsedData):
ex = []
from paramagpy import protein, fit, dataparse, metal
# Load data
prot = protein.load_pdb('../data_files/4icbH_mut.pdb')
rawData = dataparse.read_pcs('../data_files/calbindin_Er_HN_PCS.npc')
parsedData = prot.parse(rawData)
mStart = metal.Metal()
# Set the starting position to Calcium ion heteroatom in PDB
mStart.position = prot[0]['A'][('H_ CA', 77, ' ')]['CA'].position
# Calculate tensor by SVD
mFit, calc, qfac = fit.svd_gridsearch_fit_metal_from_pcs([mStart],
[parsedData],
radius=0,
points=1)
mFit[0].save('calbindin_Er_HN_PCS_tensor_position_constrained.txt')
# Calculate axially symmetric tensor by NRL
mFitAx, calcAx, qfacAx = fit.nlr_fit_metal_from_pcs([mStart], [parsedData],
params=('ax', 'b', 'g',
'x', 'y', 'z'))
mFitAx[0].save('calbindin_Er_HN_PCS_tensor_axially_symmetric.txt')
#### Plot the correlation ####
from matplotlib import pyplot as plt
fig, ax = plt.subplots(figsize=(5, 5))
# Unpack the experimental values
# Load the PCS data
rawData = dataparse.read_pcs(expPCS_fileName)
# Associate PCS data with atoms of the PDB
parsedData = prot.parse(rawData)
# Define an initial tensor
mStart = metal.Metal()
# Set the starting position to an atom close to the metal
mStart.position = prot[0]['A'][START_ATOM[0]][START_ATOM[1]].position
# Calculate an initial tensor from an SVD gridsearch
mGuess, calc, qfac = fit.svd_gridsearch_fit_metal_from_pcs(
[mStart], [parsedData],
radius=SVD_RADIUS,
points=int(SVD_RADIUS / SVD_DENSITY))
# Refine the tensor using non-linear regression
mFit, calc, qfac = fit.nlr_fit_metal_from_pcs(mGuess, [parsedData],
useracs=USE_RACS,
userads=USE_RADS)
# Save the fitted tensor to file
mFit[0].save(FITTED_TENSOR_FILE_NAME)
# Save calculated PCS values
back_calc = []
for atom in prot.get_atoms():
value = mFit[0].atom_pcs(atom, racs=USE_RACS, rads=USE_RADS)
_, mdl, chn, (_, seq, _), (atm, _) = atom.get_full_id()
from paramagpy import protein, fit, dataparse, metal
# Load data
prot = protein.load_pdb('../data_files/2bcb.pdb')
rawData = dataparse.read_pcs('../data_files/calbindin_Er_HN_PCS.npc')
parsedData = prot.parse(rawData)
# Set metal starting position
mStart = metal.Metal()
mStart.position = prot[0]['A'][56]['CA'].position
#### Averaged fit to all models ####
[mGuess], [data] = fit.svd_gridsearch_fit_metal_from_pcs([mStart],
[parsedData],
radius=10,
points=10,
ensembleAverage=False)
[mFit], [data] = fit.nlr_fit_metal_from_pcs([mGuess], [parsedData],
ensembleAverage=False)
qfac = fit.qfactor(data, ensembleAverage=False)
avg = qfac, data, mFit
#### Ensembled averaged fit to all models ####
[mGuess], [data] = fit.svd_gridsearch_fit_metal_from_pcs([mStart],
[parsedData],
radius=10,
points=10,
ensembleAverage=True)
[mFit], [data] = fit.nlr_fit_metal_from_pcs([mGuess], [parsedData],
ensembleAverage=True)
qfac = fit.qfactor(data, ensembleAverage=True)