Mercurial > repos > cpt > cpt_putative_isp

comparison cpt_putative_isp/cpt.py @ 0:10d13d0c37d3 draft

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Uploaded
author cpt
date Fri, 17 Jun 2022 13:07:15 +0000
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:10d13d0c37d3
1 #!/usr/bin/env python
2 from Bio.Seq import Seq, reverse_complement, translate
3 from Bio.SeqRecord import SeqRecord
4 from Bio import SeqIO
5 from Bio.Data import CodonTable
6 import logging
7
8 logging.basicConfig()
9 log = logging.getLogger()
10
11 PHAGE_IN_MIDDLE = re.compile("^(?P<host>.*)\s*phage (?P<phage>.*)$")
12 BACTERIOPHAGE_IN_MIDDLE = re.compile("^(?P<host>.*)\s*bacteriophage (?P<phage>.*)$")
13 STARTS_WITH_PHAGE = re.compile(
14 "^(bacterio|vibrio|Bacterio|Vibrio|)?[Pp]hage (?P<phage>.*)$"
15 )
16 NEW_STYLE_NAMES = re.compile("(?P<phage>v[A-Z]_[A-Z][a-z]{2}_.*)")
17
18
19 def phage_name_parser(name):
20 host = None
21 phage = None
22 name = name.replace(", complete genome.", "")
23 name = name.replace(", complete genome", "")
24
25 m = BACTERIOPHAGE_IN_MIDDLE.match(name)
26 if m:
27 host = m.group("host")
28 phage = m.group("phage")
29 return (host, phage)
30
31 m = PHAGE_IN_MIDDLE.match(name)
32 if m:
33 host = m.group("host")
34 phage = m.group("phage")
35 return (host, phage)
36
37 m = STARTS_WITH_PHAGE.match(name)
38 if m:
39 phage = m.group("phage")
40 return (host, phage)
41
42 m = NEW_STYLE_NAMES.match(name)
43 if m:
44 phage = m.group("phage")
45 return (host, phage)
46
47 return (host, phage)
48
49
50 class OrfFinder(object):
51 def __init__(self, table, ftype, ends, min_len, strand):
52 self.table = table
53 self.table_obj = CodonTable.ambiguous_generic_by_id[table]
54 self.ends = ends
55 self.ftype = ftype
56 self.min_len = min_len
57 self.starts = sorted(self.table_obj.start_codons)
58 self.stops = sorted(self.table_obj.stop_codons)
59 self.re_starts = re.compile("|".join(self.starts))
60 self.re_stops = re.compile("|".join(self.stops))
61 self.strand = strand
62
63 def locate(self, fasta_file, out_nuc, out_prot, out_bed, out_gff3):
64 seq_format = "fasta"
65 log.debug("Genetic code table %i" % self.table)
66 log.debug("Minimum length %i aa" % self.min_len)
67
68 out_count = 0
69
70 out_gff3.write("##gff-version 3\n")
71
72 for idx, record in enumerate(SeqIO.parse(fasta_file, seq_format)):
73 for i, (f_start, f_end, f_strand, n, t) in enumerate(
74 self.get_all_peptides(str(record.seq).upper())
75 ):
76 out_count += 1
77
78 descr = "length %i aa, %i bp, from %s..%s[%s] of %s" % (
79 len(t),
80 len(n),
81 f_start,
82 f_end,
83 f_strand,
84 record.description,
85 )
86 fid = record.id + "|%s%i" % (self.ftype, i + 1)
87
88 r = SeqRecord(Seq(n), id=fid, name="", description=descr)
89 t = SeqRecord(Seq(t), id=fid, name="", description=descr)
90
91 SeqIO.write(r, out_nuc, "fasta")
92 SeqIO.write(t, out_prot, "fasta")
93
94 nice_strand = "+" if f_strand == +1 else "-"
95
96 out_bed.write(
97 "\t".join(
98 map(str, [record.id, f_start, f_end, fid, 0, nice_strand])
99 )
100 + "\n"
101 )
102
103 out_gff3.write(
104 "\t".join(
105 map(
106 str,
107 [
108 record.id,
109 "getOrfsOrCds",
110 "CDS",
111 f_start + 1,
112 f_end,
113 ".",
114 nice_strand,
115 0,
116 "ID=%s.%s.%s" % (self.ftype, idx, i + 1),
117 ],
118 )
119 )
120 + "\n"
121 )
122 log.info("Found %i %ss", out_count, self.ftype)
123
124 def start_chop_and_trans(self, s, strict=True):
125 """Returns offset, trimmed nuc, protein."""
126 if strict:
127 assert s[-3:] in self.stops, s
128 assert len(s) % 3 == 0
129 for match in self.re_starts.finditer(s, overlapped=True):
130 # Must check the start is in frame
131 start = match.start()
132 if start % 3 == 0:
133 n = s[start:]
134 assert len(n) % 3 == 0, "%s is len %i" % (n, len(n))
135 if strict:
136 t = translate(n, self.table)
137 else:
138 # Use when missing stop codon,
139 t = "M" + translate(n[3:], self.table, to_stop=True)
140 yield start, n, t # Edited by CPT to be a generator
141
142 def break_up_frame(self, s):
143 """Returns offset, nuc, protein."""
144 start = 0
145 for match in self.re_stops.finditer(s, overlapped=True):
146 index = match.start() + 3
147 if index % 3 != 0:
148 continue
149 n = s[start:index]
150 for (offset, n, t) in self.start_chop_and_trans(n):
151 if n and len(t) >= self.min_len:
152 yield start + offset, n, t
153 start = index
154
155 def putative_genes_in_sequence(self, nuc_seq):
156 """Returns start, end, strand, nucleotides, protein.
157 Co-ordinates are Python style zero-based.
158 """
159 nuc_seq = nuc_seq.upper()
160 # TODO - Refactor to use a generator function (in start order)
161 # rather than making a list and sorting?
162 answer = []
163 full_len = len(nuc_seq)
164
165 for frame in range(0, 3):
166 for offset, n, t in self.break_up_frame(nuc_seq[frame:]):
167 start = frame + offset # zero based
168 answer.append((start, start + len(n), +1, n, t))
169
170 rc = reverse_complement(nuc_seq)
171 for frame in range(0, 3):
172 for offset, n, t in self.break_up_frame(rc[frame:]):
173 start = full_len - frame - offset # zero based
174 answer.append((start, start - len(n), -1, n, t))
175 answer.sort()
176 return answer
177
178 def get_all_peptides(self, nuc_seq):
179 """Returns start, end, strand, nucleotides, protein.
180
181 Co-ordinates are Python style zero-based.
182 """
183 # Refactored into generator by CPT
184 full_len = len(nuc_seq)
185 if self.strand != "reverse":
186 for frame in range(0, 3):
187 for offset, n, t in self.break_up_frame(nuc_seq[frame:]):
188 start = frame + offset # zero based
189 yield (start, start + len(n), +1, n, t)
190 if self.strand != "forward":
191 rc = reverse_complement(nuc_seq)
192 for frame in range(0, 3):
193 for offset, n, t in self.break_up_frame(rc[frame:]):
194 start = full_len - frame - offset # zero based
195 yield (start - len(n), start, -1, n, t)
196
197
198 class MGAFinder(object):
199 def __init__(self, table, ftype, ends, min_len):
200 self.table = table
201 self.table_obj = CodonTable.ambiguous_generic_by_id[table]
202 self.ends = ends
203 self.ftype = ftype
204 self.min_len = min_len
205 self.starts = sorted(self.table_obj.start_codons)
206 self.stops = sorted(self.table_obj.stop_codons)
207 self.re_starts = re.compile("|".join(self.starts))
208 self.re_stops = re.compile("|".join(self.stops))
209
210 def locate(self, fasta_file, out_nuc, out_prot, out_bed, out_gff3):
211 seq_format = "fasta"
212 log.debug("Genetic code table %i" % self.table)
213 log.debug("Minimum length %i aa" % self.min_len)
214
215 out_count = 0
216
217 out_gff3.write("##gff-version 3\n")
218
219 for idx, record in enumerate(SeqIO.parse(fasta_file, seq_format)):
220 for i, (f_start, f_end, f_strand, n, t) in enumerate(
221 self.get_all_peptides(str(record.seq).upper())
222 ):
223 out_count += 1
224
225 descr = "length %i aa, %i bp, from %s..%s[%s] of %s" % (
226 len(t),
227 len(n),
228 f_start,
229 f_end,
230 f_strand,
231 record.description,
232 )
233 fid = record.id + "|%s%i" % (self.ftype, i + 1)
234
235 r = SeqRecord(Seq(n), id=fid, name="", description=descr)
236 t = SeqRecord(Seq(t), id=fid, name="", description=descr)
237
238 SeqIO.write(r, out_nuc, "fasta")
239 SeqIO.write(t, out_prot, "fasta")
240
241 nice_strand = "+" if f_strand == +1 else "-"
242
243 out_bed.write(
244 "\t".join(
245 map(str, [record.id, f_start, f_end, fid, 0, nice_strand])
246 )
247 + "\n"
248 )
249
250 out_gff3.write(
251 "\t".join(
252 map(
253 str,
254 [
255 record.id,
256 "getOrfsOrCds",
257 "CDS",
258 f_start + 1,
259 f_end,
260 ".",
261 nice_strand,
262 0,
263 "ID=%s.%s.%s" % (self.ftype, idx, i + 1),
264 ],
265 )
266 )
267 + "\n"
268 )
269 log.info("Found %i %ss", out_count, self.ftype)
270
271 def start_chop_and_trans(self, s, strict=True):
272 """Returns offset, trimmed nuc, protein."""
273 if strict:
274 assert s[-3:] in self.stops, s
275 assert len(s) % 3 == 0
276 for match in self.re_starts.finditer(s, overlapped=True):
277 # Must check the start is in frame
278 start = match.start()
279 if start % 3 == 0:
280 n = s[start:]
281 assert len(n) % 3 == 0, "%s is len %i" % (n, len(n))
282 if strict:
283 t = translate(n, self.table)
284 else:
285 # Use when missing stop codon,
286 t = "M" + translate(n[3:], self.table, to_stop=True)
287 yield start, n, t
288
289 def break_up_frame(self, s):
290 """Returns offset, nuc, protein."""
291 start = 0
292 for match in self.re_stops.finditer(s, overlapped=True):
293 index = match.start() + 3
294 if index % 3 != 0:
295 continue
296 n = s[start:index]
297 for (offset, n, t) in self.start_chop_and_trans(n):
298 if n and len(t) >= self.min_len:
299 yield start + offset, n, t
300 start = index
301
302 def putative_genes_in_sequence(self, nuc_seq):
303 """Returns start, end, strand, nucleotides, protein.
304 Co-ordinates are Python style zero-based.
305 """
306 nuc_seq = nuc_seq.upper()
307 # TODO - Refactor to use a generator function (in start order)
308 # rather than making a list and sorting?
309 answer = []
310 full_len = len(nuc_seq)
311
312 for frame in range(0, 3):
313 for offset, n, t in self.break_up_frame(nuc_seq[frame:]):
314 start = frame + offset # zero based
315 answer.append((start, start + len(n), +1, n, t))
316
317 rc = reverse_complement(nuc_seq)
318 for frame in range(0, 3):
319 for offset, n, t in self.break_up_frame(rc[frame:]):
320 start = full_len - frame - offset # zero based
321 answer.append((start, start - len(n), -1, n, t))
322 answer.sort()
323 return answer
324
325 def get_all_peptides(self, nuc_seq):
326 """Returns start, end, strand, nucleotides, protein.
327
328 Co-ordinates are Python style zero-based.
329 """
330 # Refactored into generator by CPT
331
332 full_len = len(nuc_seq)
333 for frame in range(0, 3):
334 for offset, n, t in self.break_up_frame(nuc_seq[frame:]):
335 start = frame + offset # zero based
336 yield (start, start + len(n), +1, n, t)
337 rc = reverse_complement(nuc_seq)
338 for frame in range(0, 3):
339 for offset, n, t in self.break_up_frame(rc[frame:]):
340 start = full_len - frame - offset # zero based
341 yield (start - len(n), start, -1, n, t)