File size: 11,495 Bytes
b7731cd
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
# Copyright 1999 by Jeffrey Chang.  All rights reserved.
# Copyright 2000 by Jeffrey Chang.  All rights reserved.
# Revisions Copyright 2007 by Peter Cock.  All rights reserved.
# Revisions Copyright 2009 by Michiel de Hoon.  All rights reserved.
# This code is part of the Biopython distribution and governed by its
# license.  Please see the LICENSE file that should have been included
# as part of this package.
"""Parser for the prosite dat file from Prosite at ExPASy.

See https://www.expasy.org/prosite/

Tested with:
 - Release 20.43, 10-Feb-2009
 - Release 2017_03 of 15-Mar-2017.

Functions:
 - read                  Reads a Prosite file containing one Prosite record
 - parse                 Iterates over records in a Prosite file.

Classes:
 - Record                Holds Prosite data.

"""


def parse(handle):
    """Parse Prosite records.

    This function is for parsing Prosite files containing multiple
    records.

    Arguments:
     - handle   - handle to the file.

    """
    while True:
        record = __read(handle)
        if not record:
            break
        yield record


def read(handle):
    """Read one Prosite record.

    This function is for parsing Prosite files containing
    exactly one record.

    Arguments:
     - handle   - handle to the file.

    """
    record = __read(handle)
    # We should have reached the end of the record by now
    remainder = handle.read()
    if remainder:
        raise ValueError("More than one Prosite record found")
    return record


class Record:
    """Holds information from a Prosite record.

    Main attributes:
     - name           ID of the record.  e.g. ADH_ZINC
     - type           Type of entry.  e.g. PATTERN, MATRIX, or RULE
     - accession      e.g. PS00387
     - created        Date the entry was created.  (MMM-YYYY for releases
       before January 2017, DD-MMM-YYYY since January 2017)
     - data_update    Date the 'primary' data was last updated.
     - info_update    Date data other than 'primary' data was last updated.
     - pdoc           ID of the PROSITE DOCumentation.
     - description    Free-format description.
     - pattern        The PROSITE pattern.  See docs.
     - matrix         List of strings that describes a matrix entry.
     - rules          List of rule definitions (from RU lines).  (strings)
     - prorules       List of prorules (from PR lines). (strings)

    NUMERICAL RESULTS:
     - nr_sp_release  SwissProt release.
     - nr_sp_seqs     Number of seqs in that release of Swiss-Prot. (int)
     - nr_total       Number of hits in Swiss-Prot.  tuple of (hits, seqs)
     - nr_positive    True positives.  tuple of (hits, seqs)
     - nr_unknown     Could be positives.  tuple of (hits, seqs)
     - nr_false_pos   False positives.  tuple of (hits, seqs)
     - nr_false_neg   False negatives.  (int)
     - nr_partial     False negatives, because they are fragments. (int)

    COMMENTS:
     - cc_taxo_range  Taxonomic range.  See docs for format
     - cc_max_repeat  Maximum number of repetitions in a protein
     - cc_site        Interesting site.  list of tuples (pattern pos, desc.)
     - cc_skip_flag   Can this entry be ignored?
     - cc_matrix_type
     - cc_scaling_db
     - cc_author
     - cc_ft_key
     - cc_ft_desc
     - cc_version     version number (introduced in release 19.0)

    The following are all lists if tuples (swiss-prot accession, swiss-prot name).

    DATA BANK REFERENCES:
     - dr_positive
     - dr_false_neg
     - dr_false_pos
     - dr_potential   Potential hits, but fingerprint region not yet available.
     - dr_unknown     Could possibly belong
     - pdb_structs    List of PDB entries.

    """

    def __init__(self):
        """Initialize the class."""
        self.name = ""
        self.type = ""
        self.accession = ""
        self.created = ""
        self.data_update = ""
        self.info_update = ""
        self.pdoc = ""

        self.description = ""
        self.pattern = ""
        self.matrix = []
        self.rules = []
        self.prorules = []
        self.postprocessing = []

        self.nr_sp_release = ""
        self.nr_sp_seqs = ""
        self.nr_total = (None, None)
        self.nr_positive = (None, None)
        self.nr_unknown = (None, None)
        self.nr_false_pos = (None, None)
        self.nr_false_neg = None
        self.nr_partial = None

        self.cc_taxo_range = ""
        self.cc_max_repeat = ""
        self.cc_site = []
        self.cc_skip_flag = ""

        self.dr_positive = []
        self.dr_false_neg = []
        self.dr_false_pos = []
        self.dr_potential = []
        self.dr_unknown = []

        self.pdb_structs = []


# Everything below are private functions


def __read(handle):
    import re

    record = None
    for line in handle:
        keyword, value = line[:2], line[5:].rstrip()
        if keyword == "ID":
            record = Record()
            cols = value.split("; ")
            if len(cols) != 2:
                raise ValueError(f"I don't understand identification line\n{line}")
            record.name = cols[0]
            record.type = cols[1].rstrip(".")  # don't want '.'
        elif keyword == "AC":
            record.accession = value.rstrip(";")
        elif keyword == "DT":
            # e.g. from January 2017,
            # DT   01-APR-1990 CREATED; 01-APR-1990 DATA UPDATE; 01-APR-1990 INFO UPDATE.
            # Older files had brackets round the date descriptions and used MMM-YYYY
            dates = value.rstrip(".").split("; ")
            if dates[0].endswith((" (CREATED)", " CREATED")):
                # Remove last word
                record.created = dates[0].rsplit(" ", 1)[0]
            else:
                raise ValueError(f"I don't understand date line\n{line}")
            if dates[1].endswith((" (DATA UPDATE)", " DATA UPDATE")):
                # Remove last two words
                record.data_update = dates[1].rsplit(" ", 2)[0]
            else:
                raise ValueError(f"I don't understand date line\n{line}")
            if dates[2].endswith((" (INFO UPDATE)", " INFO UPDATE")):
                # Remove last two words
                record.info_update = dates[2].rsplit(" ", 2)[0]
            else:
                raise ValueError(f"I don't understand date line\n{line}")
        elif keyword == "DE":
            record.description = value
        elif keyword == "PA":
            record.pattern += value
        elif keyword == "MA":
            record.matrix.append(value)
        elif keyword == "PP":
            record.postprocessing.extend(value.split(";"))
        elif keyword == "RU":
            record.rules.append(value)
        elif keyword == "NR":
            cols = value.split(";")
            for col in cols:
                if not col:
                    continue
                qual, data = (word.lstrip() for word in col.split("="))
                if qual == "/RELEASE":
                    release, seqs = data.split(",")
                    record.nr_sp_release = release
                    record.nr_sp_seqs = int(seqs)
                elif qual == "/FALSE_NEG":
                    record.nr_false_neg = int(data)
                elif qual == "/PARTIAL":
                    record.nr_partial = int(data)
                elif qual in ["/TOTAL", "/POSITIVE", "/UNKNOWN", "/FALSE_POS"]:
                    m = re.match(r"(\d+)\((\d+)\)", data)
                    if not m:
                        raise Exception(f"Broken data {data} in comment line\n{line!r}")
                    hits = tuple(map(int, m.groups()))
                    if qual == "/TOTAL":
                        record.nr_total = hits
                    elif qual == "/POSITIVE":
                        record.nr_positive = hits
                    elif qual == "/UNKNOWN":
                        record.nr_unknown = hits
                    elif qual == "/FALSE_POS":
                        record.nr_false_pos = hits
                else:
                    raise ValueError(f"Unknown qual {qual} in comment line\n{line!r}")
        elif keyword == "CC":
            # Expect CC lines like this:
            # CC   /TAXO-RANGE=??EPV; /MAX-REPEAT=2;
            # Can (normally) split on ";" and then on "="
            cols = value.split(";")
            for col in cols:
                if not col or col[:17] == "Automatic scaling":
                    # DNAJ_2 in Release 15 has a non-standard comment line:
                    # CC   Automatic scaling using reversed database
                    # Throw it away.  (Should I keep it?)
                    continue
                if col.count("=") == 0:
                    # Missing qualifier!  Can we recover gracefully?
                    # For example, from Bug 2403, in PS50293 have:
                    # CC /AUTHOR=K_Hofmann; N_Hulo
                    continue
                qual, data = (word.lstrip() for word in col.split("="))
                if qual == "/TAXO-RANGE":
                    record.cc_taxo_range = data
                elif qual == "/MAX-REPEAT":
                    record.cc_max_repeat = data
                elif qual == "/SITE":
                    pos, desc = data.split(",")
                    record.cc_site.append((int(pos), desc))
                elif qual == "/SKIP-FLAG":
                    record.cc_skip_flag = data
                elif qual == "/MATRIX_TYPE":
                    record.cc_matrix_type = data
                elif qual == "/SCALING_DB":
                    record.cc_scaling_db = data
                elif qual == "/AUTHOR":
                    record.cc_author = data
                elif qual == "/FT_KEY":
                    record.cc_ft_key = data
                elif qual == "/FT_DESC":
                    record.cc_ft_desc = data
                elif qual == "/VERSION":
                    record.cc_version = data
                else:
                    raise ValueError(f"Unknown qual {qual} in comment line\n{line!r}")
        elif keyword == "DR":
            refs = value.split(";")
            for ref in refs:
                if not ref:
                    continue
                acc, name, type = (word.strip() for word in ref.split(","))
                if type == "T":
                    record.dr_positive.append((acc, name))
                elif type == "F":
                    record.dr_false_pos.append((acc, name))
                elif type == "N":
                    record.dr_false_neg.append((acc, name))
                elif type == "P":
                    record.dr_potential.append((acc, name))
                elif type == "?":
                    record.dr_unknown.append((acc, name))
                else:
                    raise ValueError(f"I don't understand type flag {type}")
        elif keyword == "3D":
            cols = value.split()
            for id in cols:
                record.pdb_structs.append(id.rstrip(";"))
        elif keyword == "PR":
            rules = value.split(";")
            record.prorules.extend(rules)
        elif keyword == "DO":
            record.pdoc = value.rstrip(";")
        elif keyword == "//":
            if not record:
                # Then this was the copyright statement
                continue
            break
        else:
            raise ValueError(f"Unknown keyword {keyword} found")
    else:
        return
    if not record:
        raise ValueError("Unexpected end of stream.")
    return record