mirror of
https://github.com/RosettaCommons/RFdiffusion.git
synced 2026-06-04 18:44:21 +08:00
504 lines
21 KiB
Python
Executable File
504 lines
21 KiB
Python
Executable File
#!/usr/bin/env python
|
|
import os,sys,glob,torch,random
|
|
import numpy as np
|
|
import argparse
|
|
try:
|
|
import pyrosetta
|
|
pyrosetta.init()
|
|
APPROX = False
|
|
except:
|
|
print("WARNING: pyRosetta not found, will use an approximate SSE calculation")
|
|
APPROX = True
|
|
|
|
def main():
|
|
args=get_args()
|
|
assert args.input_pdb or args.pdb_dir is not None, 'Need to provide either an input pdb (--input_pdb) or a path to pdbs (--pdb_dir)'
|
|
assert not (args.input_pdb is not None and args.pdb_dir is not None), 'Need to provide either --input_pdb or --pdb_dir, not both'
|
|
|
|
os.makedirs(args.out_dir, exist_ok=True)
|
|
if args.pdb_dir is not None:
|
|
pdbs=glob.glob(f'{args.pdb_dir}/*pdb')
|
|
else:
|
|
pdbs=[args.input_pdb]
|
|
for pdb in pdbs:
|
|
name=os.path.split(pdb)[1][:-4]
|
|
secstruc_dict=extract_secstruc(pdb)
|
|
xyz,_,_ = parse_pdb_torch(pdb)
|
|
ss, idx = ss_to_tensor(secstruc_dict)
|
|
block_adj = construct_block_adj_matrix(torch.FloatTensor(ss), torch.tensor(xyz)).float()
|
|
ss_tens, mask = mask_ss(ss, idx, max_mask=0)
|
|
ss_argmax = torch.argmax(ss_tens[:,:4], dim=1).float()
|
|
torch.save(ss_argmax, os.path.join(args.out_dir, f'{name}_ss.pt'))
|
|
torch.save(block_adj, os.path.join(args.out_dir, f'{name}_adj.pt'))
|
|
|
|
def get_args():
|
|
parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
|
|
parser.add_argument("--pdb_dir",required=False, help="path to directory of pdbs. Either pass this or the path to a specific pdb (--input_pdb)", default=None)
|
|
parser.add_argument("--input_pdb", required=False, help="path to input pdb. Either provide this of path to directory of pdbs (--pdb_dir)", default=None)
|
|
parser.add_argument("--out_dir",dest="out_dir", required=True, help='need to specify an output path')
|
|
args = parser.parse_args()
|
|
return args
|
|
|
|
|
|
def extract_secstruc(fn):
|
|
pdb=parse_pdb(fn)
|
|
idx = pdb['idx']
|
|
if APPROX:
|
|
aa_sequence = pdb["seq"]
|
|
secstruct = get_sse(pdb["xyz"][:,1])
|
|
else:
|
|
dssp = pyrosetta.rosetta.core.scoring.dssp
|
|
pose = pyrosetta.io.pose_from_pdb(fn)
|
|
dssp.Dssp(pose).insert_ss_into_pose(pose, True)
|
|
aa_sequence = pose.sequence()
|
|
secstruct = pose.secstruct()
|
|
secstruc_dict = {'sequence':[i for i in aa_sequence],
|
|
'idx':[int(i) for i in idx],
|
|
'ss':[i for i in secstruct]}
|
|
return secstruc_dict
|
|
|
|
def ss_to_tensor(ss):
|
|
"""
|
|
Function to convert ss files to indexed tensors
|
|
0 = Helix
|
|
1 = Strand
|
|
2 = Loop
|
|
3 = Mask/unknown
|
|
4 = idx for pdb
|
|
"""
|
|
ss_conv = {'H':0,'E':1,'L':2}
|
|
idx = np.array(ss['idx'])
|
|
ss_int = np.array([int(ss_conv[i]) for i in ss['ss']])
|
|
return ss_int, idx
|
|
|
|
def mask_ss(ss, idx, min_mask = 0, max_mask = 1.0):
|
|
mask_prop = random.uniform(min_mask, max_mask)
|
|
transitions = np.where(ss[:-1] - ss[1:] != 0)[0] #gets last index of each block of ss
|
|
stuck_counter = 0
|
|
while len(ss[ss == 3])/len(ss) < mask_prop or stuck_counter > 100:
|
|
width = random.randint(1,9)
|
|
start = random.choice(transitions)
|
|
offset = random.randint(-8,1)
|
|
try:
|
|
|
|
ss[start+offset:start+offset+width] = 3
|
|
except:
|
|
stuck_counter += 1
|
|
pass
|
|
ss = torch.tensor(ss)
|
|
ss = torch.nn.functional.one_hot(ss, num_classes=4)
|
|
ss = torch.cat((ss, torch.tensor(idx)[...,None]), dim=-1)
|
|
# mask = torch.where(torch.argmax(ss[:,:-1], dim=-1) == 3, False, True)
|
|
mask=torch.tensor(np.where(np.argmax(ss[:,:-1].numpy(), axis=-1) == 3))
|
|
return ss, mask
|
|
|
|
def generate_Cbeta(N,Ca,C):
|
|
# recreate Cb given N,Ca,C
|
|
b = Ca - N
|
|
c = C - Ca
|
|
a = torch.cross(b, c, dim=-1)
|
|
#Cb = -0.58273431*a + 0.56802827*b - 0.54067466*c + Ca
|
|
# fd: below matches sidechain generator (=Rosetta params)
|
|
Cb = -0.57910144*a + 0.5689693*b - 0.5441217*c + Ca
|
|
|
|
return Cb
|
|
|
|
def get_pair_dist(a, b):
|
|
"""calculate pair distances between two sets of points
|
|
|
|
Parameters
|
|
----------
|
|
a,b : pytorch tensors of shape [batch,nres,3]
|
|
store Cartesian coordinates of two sets of atoms
|
|
Returns
|
|
-------
|
|
dist : pytorch tensor of shape [batch,nres,nres]
|
|
stores paitwise distances between atoms in a and b
|
|
"""
|
|
|
|
dist = torch.cdist(a, b, p=2)
|
|
return dist
|
|
|
|
|
|
def construct_block_adj_matrix( sstruct, xyz, cutoff=6, include_loops=False ):
|
|
'''
|
|
Given a sstruct specification and backbone coordinates, build a block adjacency matrix.
|
|
|
|
Input:
|
|
|
|
sstruct (torch.FloatTensor): (L) length tensor with numeric encoding of sstruct at each position
|
|
|
|
xyz (torch.FloatTensor): (L,3,3) tensor of Cartesian coordinates of backbone N,Ca,C atoms
|
|
|
|
cutoff (float): The Cb distance cutoff under which residue pairs are considered adjacent
|
|
By eye, Nate thinks 6A is a good Cb distance cutoff
|
|
|
|
Output:
|
|
|
|
block_adj (torch.FloatTensor): (L,L) boolean matrix where adjacent secondary structure contacts are 1
|
|
'''
|
|
|
|
L = xyz.shape[0]
|
|
|
|
# three anchor atoms
|
|
N = xyz[:,0]
|
|
Ca = xyz[:,1]
|
|
C = xyz[:,2]
|
|
|
|
# recreate Cb given N,Ca,C
|
|
Cb = generate_Cbeta(N,Ca,C)
|
|
|
|
# May need a batch dimension - NRB
|
|
dist = get_pair_dist(Cb,Cb) # [L,L]
|
|
dist[torch.isnan(dist)] = 999.9
|
|
|
|
dist += 999.9*torch.eye(L,device=xyz.device)
|
|
# Now we have dist matrix and sstruct specification, turn this into a block adjacency matrix
|
|
# There is probably a way to do this in closed-form with a beautiful einsum but I am going to do the loop approach
|
|
|
|
# First: Construct a list of segments and the index at which they begin and end
|
|
in_segment = True
|
|
segments = []
|
|
|
|
begin = -1
|
|
end = -1
|
|
|
|
for i in range(sstruct.shape[0]):
|
|
# Starting edge case
|
|
if i == 0:
|
|
begin = 0
|
|
continue
|
|
|
|
if not sstruct[i] == sstruct[i-1]:
|
|
end = i
|
|
segments.append( (sstruct[i-1], begin, end) )
|
|
|
|
begin = i
|
|
|
|
# Ending edge case: last segment is length one
|
|
if not end == sstruct.shape[0]:
|
|
segments.append( (sstruct[-1], begin, sstruct.shape[0]) )
|
|
|
|
|
|
block_adj = torch.zeros_like(dist)
|
|
for i in range(len(segments)):
|
|
curr_segment = segments[i]
|
|
|
|
if curr_segment[0] == 2 and not include_loops: continue
|
|
|
|
begin_i = curr_segment[1]
|
|
end_i = curr_segment[2]
|
|
for j in range(i+1, len(segments)):
|
|
j_segment = segments[j]
|
|
|
|
if j_segment[0] == 2 and not include_loops: continue
|
|
|
|
begin_j = j_segment[1]
|
|
end_j = j_segment[2]
|
|
|
|
if torch.any( dist[begin_i:end_i, begin_j:end_j] < cutoff ):
|
|
# Matrix is symmetic
|
|
block_adj[begin_i:end_i, begin_j:end_j] = torch.ones(end_i - begin_i, end_j - begin_j)
|
|
block_adj[begin_j:end_j, begin_i:end_i] = torch.ones(end_j - begin_j, end_i - begin_i)
|
|
return block_adj
|
|
|
|
def parse_pdb_torch(filename):
|
|
lines = open(filename,'r').readlines()
|
|
return parse_pdb_lines_torch(lines)
|
|
|
|
#'''
|
|
def parse_pdb_lines_torch(lines):
|
|
|
|
# indices of residues observed in the structure
|
|
pdb_idx = []
|
|
for l in lines:
|
|
if l[:4]=="ATOM" and l[12:16].strip()=="CA":
|
|
idx = ( l[21:22].strip(), int(l[22:26].strip()) )
|
|
if idx not in pdb_idx:
|
|
pdb_idx.append(idx)
|
|
|
|
# 4 BB + up to 10 SC atoms
|
|
xyz = np.full((len(pdb_idx), 27, 3), np.nan, dtype=np.float32)
|
|
for l in lines:
|
|
if l[:4] != "ATOM":
|
|
continue
|
|
chain, resNo, atom, aa = l[21:22], int(l[22:26]), ' '+l[12:16].strip().ljust(3), l[17:20]
|
|
idx = pdb_idx.index((chain,resNo))
|
|
for i_atm, tgtatm in enumerate(aa2long[aa2num[aa]]):
|
|
if tgtatm == atom:
|
|
xyz[idx,i_atm,:] = [float(l[30:38]), float(l[38:46]), float(l[46:54])]
|
|
break
|
|
# save atom mask
|
|
mask = np.logical_not(np.isnan(xyz[...,0]))
|
|
xyz[np.isnan(xyz[...,0])] = 0.0
|
|
|
|
return xyz,mask,np.array(pdb_idx)
|
|
|
|
def parse_pdb(filename, **kwargs):
|
|
'''extract xyz coords for all heavy atoms'''
|
|
lines = open(filename,'r').readlines()
|
|
return parse_pdb_lines(lines, **kwargs)
|
|
|
|
def parse_pdb_lines(lines, parse_hetatom=False, ignore_het_h=True):
|
|
# indices of residues observed in the structure
|
|
res = [(l[22:26],l[17:20]) for l in lines if l[:4]=="ATOM" and l[12:16].strip()=="CA"]
|
|
seq = [aa2num[r[1]] if r[1] in aa2num.keys() else 20 for r in res]
|
|
pdb_idx = [( l[21:22].strip(), int(l[22:26].strip()) ) for l in lines if l[:4]=="ATOM" and l[12:16].strip()=="CA"] # chain letter, res num
|
|
|
|
# 4 BB + up to 10 SC atoms
|
|
xyz = np.full((len(res), 27, 3), np.nan, dtype=np.float32)
|
|
for l in lines:
|
|
if l[:4] != "ATOM":
|
|
continue
|
|
chain, resNo, atom, aa = l[21:22], int(l[22:26]), ' '+l[12:16].strip().ljust(3), l[17:20]
|
|
idx = pdb_idx.index((chain,resNo))
|
|
for i_atm, tgtatm in enumerate(aa2long[aa2num[aa]]):
|
|
if tgtatm is not None and tgtatm.strip() == atom.strip(): # ignore whitespace
|
|
xyz[idx,i_atm,:] = [float(l[30:38]), float(l[38:46]), float(l[46:54])]
|
|
break
|
|
|
|
# save atom mask
|
|
mask = np.logical_not(np.isnan(xyz[...,0]))
|
|
xyz[np.isnan(xyz[...,0])] = 0.0
|
|
# remove duplicated (chain, resi)
|
|
new_idx = []
|
|
i_unique = []
|
|
for i,idx in enumerate(pdb_idx):
|
|
if idx not in new_idx:
|
|
new_idx.append(idx)
|
|
i_unique.append(i)
|
|
|
|
pdb_idx = new_idx
|
|
xyz = xyz[i_unique]
|
|
mask = mask[i_unique]
|
|
seq = np.array(seq)[i_unique]
|
|
|
|
out = {'xyz':xyz, # cartesian coordinates, [Lx14]
|
|
'mask':mask, # mask showing which atoms are present in the PDB file, [Lx14]
|
|
'idx':np.array([i[1] for i in pdb_idx]), # residue numbers in the PDB file, [L]
|
|
'seq':np.array(seq), # amino acid sequence, [L]
|
|
'pdb_idx': pdb_idx, # list of (chain letter, residue number) in the pdb file, [L]
|
|
}
|
|
# heteroatoms (ligands, etc)
|
|
if parse_hetatom:
|
|
xyz_het, info_het = [], []
|
|
for l in lines:
|
|
if l[:6]=='HETATM' and not (ignore_het_h and l[77]=='H'):
|
|
info_het.append(dict(
|
|
idx=int(l[7:11]),
|
|
atom_id=l[12:16],
|
|
atom_type=l[77],
|
|
name=l[16:20]
|
|
))
|
|
xyz_het.append([float(l[30:38]), float(l[38:46]), float(l[46:54])])
|
|
|
|
out['xyz_het'] = np.array(xyz_het)
|
|
out['info_het'] = info_het
|
|
|
|
return out
|
|
|
|
num2aa=[
|
|
'ALA','ARG','ASN','ASP','CYS',
|
|
'GLN','GLU','GLY','HIS','ILE',
|
|
'LEU','LYS','MET','PHE','PRO',
|
|
'SER','THR','TRP','TYR','VAL',
|
|
'UNK','MAS',
|
|
]
|
|
|
|
aa2num= {x:i for i,x in enumerate(num2aa)}
|
|
# full sc atom representation (Nx14)
|
|
aa2long=[
|
|
(" N "," CA "," C "," O "," CB ", None, None, None, None, None, None, None, None, None," H "," HA ","1HB ","2HB ","3HB ", None, None, None, None, None, None, None, None), # ala
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD "," NE "," CZ "," NH1"," NH2", None, None, None," H "," HA ","1HB ","2HB ","1HG ","2HG ","1HD ","2HD "," HE ","1HH1","2HH1","1HH2","2HH2"), # arg
|
|
(" N "," CA "," C "," O "," CB "," CG "," OD1"," ND2", None, None, None, None, None, None," H "," HA ","1HB ","2HB ","1HD2","2HD2", None, None, None, None, None, None, None), # asn
|
|
(" N "," CA "," C "," O "," CB "," CG "," OD1"," OD2", None, None, None, None, None, None," H "," HA ","1HB ","2HB ", None, None, None, None, None, None, None, None, None), # asp
|
|
(" N "," CA "," C "," O "," CB "," SG ", None, None, None, None, None, None, None, None," H "," HA ","1HB ","2HB "," HG ", None, None, None, None, None, None, None, None), # cys
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD "," OE1"," NE2", None, None, None, None, None," H "," HA ","1HB ","2HB ","1HG ","2HG ","1HE2","2HE2", None, None, None, None, None), # gln
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD "," OE1"," OE2", None, None, None, None, None," H "," HA ","1HB ","2HB ","1HG ","2HG ", None, None, None, None, None, None, None), # glu
|
|
(" N "," CA "," C "," O ", None, None, None, None, None, None, None, None, None, None," H ","1HA ","2HA ", None, None, None, None, None, None, None, None, None, None), # gly
|
|
(" N "," CA "," C "," O "," CB "," CG "," ND1"," CD2"," CE1"," NE2", None, None, None, None," H "," HA ","1HB ","2HB "," HD2"," HE1"," HE2", None, None, None, None, None, None), # his
|
|
(" N "," CA "," C "," O "," CB "," CG1"," CG2"," CD1", None, None, None, None, None, None," H "," HA "," HB ","1HG2","2HG2","3HG2","1HG1","2HG1","1HD1","2HD1","3HD1", None, None), # ile
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD1"," CD2", None, None, None, None, None, None," H "," HA ","1HB ","2HB "," HG ","1HD1","2HD1","3HD1","1HD2","2HD2","3HD2", None, None), # leu
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD "," CE "," NZ ", None, None, None, None, None," H "," HA ","1HB ","2HB ","1HG ","2HG ","1HD ","2HD ","1HE ","2HE ","1HZ ","2HZ ","3HZ "), # lys
|
|
(" N "," CA "," C "," O "," CB "," CG "," SD "," CE ", None, None, None, None, None, None," H "," HA ","1HB ","2HB ","1HG ","2HG ","1HE ","2HE ","3HE ", None, None, None, None), # met
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD1"," CD2"," CE1"," CE2"," CZ ", None, None, None," H "," HA ","1HB ","2HB "," HD1"," HD2"," HE1"," HE2"," HZ ", None, None, None, None), # phe
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD ", None, None, None, None, None, None, None," HA ","1HB ","2HB ","1HG ","2HG ","1HD ","2HD ", None, None, None, None, None, None), # pro
|
|
(" N "," CA "," C "," O "," CB "," OG ", None, None, None, None, None, None, None, None," H "," HG "," HA ","1HB ","2HB ", None, None, None, None, None, None, None, None), # ser
|
|
(" N "," CA "," C "," O "," CB "," OG1"," CG2", None, None, None, None, None, None, None," H "," HG1"," HA "," HB ","1HG2","2HG2","3HG2", None, None, None, None, None, None), # thr
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD1"," CD2"," NE1"," CE2"," CE3"," CZ2"," CZ3"," CH2"," H "," HA ","1HB ","2HB "," HD1"," HE1"," HZ2"," HH2"," HZ3"," HE3", None, None, None), # trp
|
|
(" N "," CA "," C "," O "," CB "," CG "," CD1"," CD2"," CE1"," CE2"," CZ "," OH ", None, None," H "," HA ","1HB ","2HB "," HD1"," HE1"," HE2"," HD2"," HH ", None, None, None, None), # tyr
|
|
(" N "," CA "," C "," O "," CB "," CG1"," CG2", None, None, None, None, None, None, None," H "," HA "," HB ","1HG1","2HG1","3HG1","1HG2","2HG2","3HG2", None, None, None, None), # val
|
|
(" N "," CA "," C "," O "," CB ", None, None, None, None, None, None, None, None, None," H "," HA ","1HB ","2HB ","3HB ", None, None, None, None, None, None, None, None), # unk
|
|
(" N "," CA "," C "," O "," CB ", None, None, None, None, None, None, None, None, None," H "," HA ","1HB ","2HB ","3HB ", None, None, None, None, None, None, None, None), # mask
|
|
]
|
|
|
|
def get_sse(ca_coord):
|
|
'''
|
|
calculates the SSE of a peptide chain based on the P-SEA algorithm (Labesse 1997)
|
|
code borrowed from biokite: https://github.com/biokit/biokit
|
|
'''
|
|
def vector_dot(v1,v2): return (v1*v2).sum(-1)
|
|
def norm_vector(v): return v / np.linalg.norm(v, axis=-1, keepdims=True)
|
|
def displacement(atoms1, atoms2):
|
|
v1 = np.asarray(atoms1)
|
|
v2 = np.asarray(atoms2)
|
|
if len(v1.shape) <= len(v2.shape):
|
|
diff = v2 - v1
|
|
else:
|
|
diff = -(v1 - v2)
|
|
return diff
|
|
def distance(atoms1, atoms2):
|
|
diff = displacement(atoms1, atoms2)
|
|
return np.sqrt(vector_dot(diff, diff))
|
|
|
|
def angle(atoms1, atoms2, atoms3):
|
|
v1 = norm_vector(displacement(atoms1, atoms2))
|
|
v2 = norm_vector(displacement(atoms3, atoms2))
|
|
return np.arccos(vector_dot(v1,v2))
|
|
|
|
def dihedral(atoms1, atoms2, atoms3, atoms4):
|
|
v1 = norm_vector(displacement(atoms1, atoms2))
|
|
v2 = norm_vector(displacement(atoms2, atoms3))
|
|
v3 = norm_vector(displacement(atoms3, atoms4))
|
|
|
|
n1 = np.cross(v1, v2)
|
|
n2 = np.cross(v2, v3)
|
|
|
|
# Calculation using atan2, to ensure the correct sign of the angle
|
|
x = vector_dot(n1,n2)
|
|
y = vector_dot(np.cross(n1,n2), v2)
|
|
return np.arctan2(y,x)
|
|
|
|
_radians_to_angle = 2*np.pi/360
|
|
|
|
_r_helix = ((89-12)*_radians_to_angle, (89+12)*_radians_to_angle)
|
|
_a_helix = ((50-20)*_radians_to_angle, (50+20)*_radians_to_angle)
|
|
_d2_helix = ((5.5-0.5), (5.5+0.5))
|
|
_d3_helix = ((5.3-0.5), (5.3+0.5))
|
|
_d4_helix = ((6.4-0.6), (6.4+0.6))
|
|
|
|
_r_strand = ((124-14)*_radians_to_angle, (124+14)*_radians_to_angle)
|
|
_a_strand = ((-180)*_radians_to_angle, (-125)*_radians_to_angle,
|
|
(145)*_radians_to_angle, (180)*_radians_to_angle)
|
|
_d2_strand = ((6.7-0.6), (6.7+0.6))
|
|
_d3_strand = ((9.9-0.9), (9.9+0.9))
|
|
_d4_strand = ((12.4-1.1), (12.4+1.1))
|
|
|
|
# Filter all CA atoms in the relevant chain.
|
|
|
|
d2i_coord = np.full(( len(ca_coord), 2, 3 ), np.nan)
|
|
d3i_coord = np.full(( len(ca_coord), 2, 3 ), np.nan)
|
|
d4i_coord = np.full(( len(ca_coord), 2, 3 ), np.nan)
|
|
ri_coord = np.full(( len(ca_coord), 3, 3 ), np.nan)
|
|
ai_coord = np.full(( len(ca_coord), 4, 3 ), np.nan)
|
|
|
|
# The distances and angles are not defined for the entire interval,
|
|
# therefore the indices do not have the full range
|
|
# Values that are not defined are NaN
|
|
for i in range(1, len(ca_coord)-1): d2i_coord[i] = (ca_coord[i-1], ca_coord[i+1])
|
|
for i in range(1, len(ca_coord)-2): d3i_coord[i] = (ca_coord[i-1], ca_coord[i+2])
|
|
for i in range(1, len(ca_coord)-3): d4i_coord[i] = (ca_coord[i-1], ca_coord[i+3])
|
|
for i in range(1, len(ca_coord)-1): ri_coord[i] = (ca_coord[i-1], ca_coord[i], ca_coord[i+1])
|
|
for i in range(1, len(ca_coord)-2): ai_coord[i] = (ca_coord[i-1], ca_coord[i], ca_coord[i+1], ca_coord[i+2])
|
|
|
|
d2i = distance(d2i_coord[:,0], d2i_coord[:,1])
|
|
d3i = distance(d3i_coord[:,0], d3i_coord[:,1])
|
|
d4i = distance(d4i_coord[:,0], d4i_coord[:,1])
|
|
ri = angle(ri_coord[:,0], ri_coord[:,1], ri_coord[:,2])
|
|
ai = dihedral(ai_coord[:,0], ai_coord[:,1], ai_coord[:,2], ai_coord[:,3])
|
|
|
|
sse = ["L"] * len(ca_coord)
|
|
|
|
# Annotate helices
|
|
# Find CA that meet criteria for potential helices
|
|
is_pot_helix = np.zeros(len(sse), dtype=bool)
|
|
for i in range(len(sse)):
|
|
if (
|
|
d3i[i] >= _d3_helix[0] and d3i[i] <= _d3_helix[1]
|
|
and d4i[i] >= _d4_helix[0] and d4i[i] <= _d4_helix[1]
|
|
) or (
|
|
ri[i] >= _r_helix[0] and ri[i] <= _r_helix[1]
|
|
and ai[i] >= _a_helix[0] and ai[i] <= _a_helix[1]
|
|
):
|
|
is_pot_helix[i] = True
|
|
# Real helices are 5 consecutive helix elements
|
|
is_helix = np.zeros(len(sse), dtype=bool)
|
|
counter = 0
|
|
for i in range(len(sse)):
|
|
if is_pot_helix[i]:
|
|
counter += 1
|
|
else:
|
|
if counter >= 5:
|
|
is_helix[i-counter : i] = True
|
|
counter = 0
|
|
# Extend the helices by one at each end if CA meets extension criteria
|
|
i = 0
|
|
while i < len(sse):
|
|
if is_helix[i]:
|
|
sse[i] = "H"
|
|
if (
|
|
d3i[i-1] >= _d3_helix[0] and d3i[i-1] <= _d3_helix[1]
|
|
) or (
|
|
ri[i-1] >= _r_helix[0] and ri[i-1] <= _r_helix[1]
|
|
):
|
|
sse[i-1] = "H"
|
|
sse[i] = "H"
|
|
if (
|
|
d3i[i+1] >= _d3_helix[0] and d3i[i+1] <= _d3_helix[1]
|
|
) or (
|
|
ri[i+1] >= _r_helix[0] and ri[i+1] <= _r_helix[1]
|
|
):
|
|
sse[i+1] = "H"
|
|
i += 1
|
|
|
|
# Annotate sheets
|
|
# Find CA that meet criteria for potential strands
|
|
is_pot_strand = np.zeros(len(sse), dtype=bool)
|
|
for i in range(len(sse)):
|
|
if ( d2i[i] >= _d2_strand[0] and d2i[i] <= _d2_strand[1]
|
|
and d3i[i] >= _d3_strand[0] and d3i[i] <= _d3_strand[1]
|
|
and d4i[i] >= _d4_strand[0] and d4i[i] <= _d4_strand[1]
|
|
) or (
|
|
ri[i] >= _r_strand[0] and ri[i] <= _r_strand[1]
|
|
and ( (ai[i] >= _a_strand[0] and ai[i] <= _a_strand[1])
|
|
or (ai[i] >= _a_strand[2] and ai[i] <= _a_strand[3]))
|
|
):
|
|
is_pot_strand[i] = True
|
|
# Real strands are 5 consecutive strand elements,
|
|
# or shorter fragments of at least 3 consecutive strand residues,
|
|
# if they are in hydrogen bond proximity to 5 other residues
|
|
pot_strand_coord = ca_coord[is_pot_strand]
|
|
is_strand = np.zeros(len(sse), dtype=bool)
|
|
counter = 0
|
|
contacts = 0
|
|
for i in range(len(sse)):
|
|
if is_pot_strand[i]:
|
|
counter += 1
|
|
coord = ca_coord[i]
|
|
for strand_coord in ca_coord:
|
|
dist = distance(coord, strand_coord)
|
|
if dist >= 4.2 and dist <= 5.2:
|
|
contacts += 1
|
|
else:
|
|
if counter >= 4:
|
|
is_strand[i-counter : i] = True
|
|
elif counter == 3 and contacts >= 5:
|
|
is_strand[i-counter : i] = True
|
|
counter = 0
|
|
contacts = 0
|
|
# Extend the strands by one at each end if CA meets extension criteria
|
|
i = 0
|
|
while i < len(sse):
|
|
if is_strand[i]:
|
|
sse[i] = "E"
|
|
if d3i[i-1] >= _d3_strand[0] and d3i[i-1] <= _d3_strand[1]:
|
|
sse[i-1] = "E"
|
|
sse[i] = "E"
|
|
if d3i[i+1] >= _d3_strand[0] and d3i[i+1] <= _d3_strand[1]:
|
|
sse[i+1] = "E"
|
|
i += 1
|
|
return sse
|
|
|
|
if __name__ == "__main__":
|
|
main()
|