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| """Bio.SeqIO support for the "pir" (aka PIR or NBRF) file format. |
| |
| This module is for reading and writing PIR or NBRF format files as |
| SeqRecord objects. |
| |
| You are expected to use this module via the Bio.SeqIO functions, or if |
| the file contains a sequence alignment, optionally via Bio.AlignIO instead. |
| |
| This format was introduced for the Protein Information Resource (PIR), a |
| project of the National Biomedical Research Foundation (NBRF). The PIR |
| database itself is now part of UniProt. |
| |
| The file format is described online at: |
| http://www.ebi.ac.uk/help/pir_frame.html |
| http://www.cmbi.kun.nl/bioinf/tools/crab_pir.html (currently down) |
| |
| An example file in this format would be:: |
| |
| >P1;CRAB_ANAPL |
| ALPHA CRYSTALLIN B CHAIN (ALPHA(B)-CRYSTALLIN). |
| MDITIHNPLI RRPLFSWLAP SRIFDQIFGE HLQESELLPA SPSLSPFLMR |
| SPIFRMPSWL ETGLSEMRLE KDKFSVNLDV KHFSPEELKV KVLGDMVEIH |
| GKHEERQDEH GFIAREFNRK YRIPADVDPL TITSSLSLDG VLTVSAPRKQ |
| SDVPERSIPI TREEKPAIAG AQRK* |
| |
| >P1;CRAB_BOVIN |
| ALPHA CRYSTALLIN B CHAIN (ALPHA(B)-CRYSTALLIN). |
| MDIAIHHPWI RRPFFPFHSP SRLFDQFFGE HLLESDLFPA STSLSPFYLR |
| PPSFLRAPSW IDTGLSEMRL EKDRFSVNLD VKHFSPEELK VKVLGDVIEV |
| HGKHEERQDE HGFISREFHR KYRIPADVDP LAITSSLSSD GVLTVNGPRK |
| QASGPERTIP ITREEKPAVT AAPKK* |
| |
| Or, an example of a multiple sequence alignment:: |
| |
| >P1;S27231 |
| rhodopsin - northern leopard frog |
| MNGTEGPNFY IPMSNKTGVV RSPFDYPQYY LAEPWKYSVL AAYMFLLILL GLPINFMTLY |
| VTIQHKKLRT PLNYILLNLG VCNHFMVLCG FTITMYTSLH GYFVFGQTGC YFEGFFATLG |
| GEIALWSLVV LAIERYIVVC KPMSNFRFGE NHAMMGVAFT WIMALACAVP PLFGWSRYIP |
| EGMQCSCGVD YYTLKPEVNN ESFVIYMFVV HFLIPLIIIS FCYGRLVCTV KEAAAQQQES |
| ATTQKAEKEV TRMVIIMVIF FLICWVPYAY VAFYIFTHQG SEFGPIFMTV PAFFAKSSAI |
| YNPVIYIMLN KQFRNCMITT LCCGKNPFGD DDASSAATSK TEATSVSTSQ VSPA* |
| |
| >P1;I51200 |
| rhodopsin - African clawed frog |
| MNGTEGPNFY VPMSNKTGVV RSPFDYPQYY LAEPWQYSAL AAYMFLLILL GLPINFMTLF |
| VTIQHKKLRT PLNYILLNLV FANHFMVLCG FTVTMYTSMH GYFIFGPTGC YIEGFFATLG |
| GEVALWSLVV LAVERYIVVC KPMANFRFGE NHAIMGVAFT WIMALSCAAP PLFGWSRYIP |
| EGMQCSCGVD YYTLKPEVNN ESFVIYMFIV HFTIPLIVIF FCYGRLLCTV KEAAAQQQES |
| LTTQKAEKEV TRMVVIMVVF FLICWVPYAY VAFYIFTHQG SNFGPVFMTV PAFFAKSSAI |
| YNPVIYIVLN KQFRNCLITT LCCGKNPFGD EDGSSAATSK TEASSVSSSQ VSPA* |
| |
| >P1;JN0120 |
| rhodopsin - Japanese lamprey |
| MNGTEGDNFY VPFSNKTGLA RSPYEYPQYY LAEPWKYSAL AAYMFFLILV GFPVNFLTLF |
| VTVQHKKLRT PLNYILLNLA MANLFMVLFG FTVTMYTSMN GYFVFGPTMC SIEGFFATLG |
| GEVALWSLVV LAIERYIVIC KPMGNFRFGN THAIMGVAFT WIMALACAAP PLVGWSRYIP |
| EGMQCSCGPD YYTLNPNFNN ESYVVYMFVV HFLVPFVIIF FCYGRLLCTV KEAAAAQQES |
| ASTQKAEKEV TRMVVLMVIG FLVCWVPYAS VAFYIFTHQG SDFGATFMTL PAFFAKSSAL |
| YNPVIYILMN KQFRNCMITT LCCGKNPLGD DE-SGASTSKT EVSSVSTSPV SPA* |
| |
| |
| As with the FASTA format, each record starts with a line beginning with ">" |
| character. There is then a two letter sequence type (P1, F1, DL, DC, RL, |
| RC, or XX), a semi colon, and the identification code. The second like is |
| free text description. The remaining lines contain the sequence itself, |
| terminating in an asterisk. Space separated blocks of ten letters as shown |
| above are typical. |
| |
| Sequence codes and their meanings: |
| - P1 - Protein (complete) |
| - F1 - Protein (fragment) |
| - D1 - DNA (e.g. EMBOSS seqret output) |
| - DL - DNA (linear) |
| - DC - DNA (circular) |
| - RL - RNA (linear) |
| - RC - RNA (circular) |
| - N3 - tRNA |
| - N1 - Other functional RNA |
| - XX - Unknown |
| |
| """ |
|
|
| from Bio.Seq import Seq |
| from Bio.SeqRecord import SeqRecord |
|
|
| from .Interfaces import _get_seq_string |
| from .Interfaces import SequenceIterator |
| from .Interfaces import SequenceWriter |
|
|
| _pir_mol_type = { |
| "P1": "protein", |
| "F1": "protein", |
| "D1": "DNA", |
| "DL": "DNA", |
| "DC": "DNA", |
| "RL": "RNA", |
| "RC": "RNA", |
| "N3": "RNA", |
| "XX": None, |
| } |
|
|
|
|
| class PirIterator(SequenceIterator): |
| """Parser for PIR files.""" |
|
|
| modes = "t" |
|
|
| def __init__(self, source): |
| """Iterate over a PIR file and yield SeqRecord objects. |
| |
| source - file-like object or a path to a file. |
| |
| Examples |
| -------- |
| >>> with open("NBRF/DMB_prot.pir") as handle: |
| ... for record in PirIterator(handle): |
| ... print("%s length %i" % (record.id, len(record))) |
| HLA:HLA00489 length 263 |
| HLA:HLA00490 length 94 |
| HLA:HLA00491 length 94 |
| HLA:HLA00492 length 80 |
| HLA:HLA00493 length 175 |
| HLA:HLA01083 length 188 |
| |
| """ |
| super().__init__(source, fmt="Pir") |
| |
| for line in self.stream: |
| if line[0] == ">": |
| self._line = line |
| break |
| else: |
| self._line = None |
|
|
| def __next__(self): |
| """Iterate over the records in the PIR file.""" |
| line = self._line |
| if line is None: |
| raise StopIteration |
|
|
| pir_type = line[1:3] |
| if pir_type not in _pir_mol_type or line[3] != ";": |
| raise ValueError( |
| "Records should start with '>XX;' where XX is a valid sequence type" |
| ) |
|
|
| identifier = line[4:].strip() |
| description = self.stream.readline() |
| if description == "": |
| raise StopIteration |
| else: |
| description = description.strip() |
|
|
| lines = [] |
| for line in self.stream: |
| if line[0] == ">": |
| self._line = line |
| break |
| |
| lines.append(line.rstrip().replace(" ", "")) |
| else: |
| self._line = None |
| seq = "".join(lines) |
| if seq[-1] != "*": |
| |
| |
| raise ValueError("Sequences in PIR files should include a * terminator!") |
|
|
| |
| record = SeqRecord( |
| Seq(seq[:-1]), id=identifier, name=identifier, description=description |
| ) |
| record.annotations["PIR-type"] = pir_type |
| if _pir_mol_type[pir_type]: |
| record.annotations["molecule_type"] = _pir_mol_type[pir_type] |
| return record |
|
|
|
|
| class PirWriter(SequenceWriter): |
| """Class to write PIR format files.""" |
|
|
| modes = "t" |
|
|
| def __init__(self, handle, wrap=60, record2title=None, code=None): |
| """Create a PIR writer. |
| |
| Arguments: |
| - handle - Handle to an output file, e.g. as returned |
| by open(filename, "w") |
| - wrap - Optional line length used to wrap sequence lines. |
| Defaults to wrapping the sequence at 60 characters |
| Use zero (or None) for no wrapping, giving a single |
| long line for the sequence. |
| - record2title - Optional function to return the text to be |
| used for the title line of each record. By default |
| a combination of the record.id, record.name and |
| record.description is used. |
| - code - Optional sequence code must be one of P1, F1, |
| D1, DL, DC, RL, RC, N3 and XX. By default None is used, |
| which means auto detection based on the molecule type |
| in the record annotation. |
| |
| You can either use:: |
| |
| handle = open(filename, "w") |
| writer = PirWriter(handle) |
| writer.write_file(myRecords) |
| handle.close() |
| |
| Or, follow the sequential file writer system, for example:: |
| |
| handle = open(filename, "w") |
| writer = PirWriter(handle) |
| ... |
| Multiple writer.write_record() and/or writer.write_records() calls |
| ... |
| handle.close() |
| |
| """ |
| super().__init__(handle) |
| self.wrap = None |
| if wrap: |
| if wrap < 1: |
| raise ValueError("wrap should be None, 0, or a positive integer") |
| self.wrap = wrap |
| self.record2title = record2title |
| self.code = code |
|
|
| def write_record(self, record): |
| """Write a single PIR record to the file.""" |
| if self.record2title: |
| title = self.clean(self.record2title(record)) |
| else: |
| title = self.clean(record.id) |
|
|
| if record.name and record.description: |
| description = self.clean(record.name + " - " + record.description) |
| elif record.name and not record.description: |
| description = self.clean(record.name) |
| else: |
| description = self.clean(record.description) |
|
|
| if self.code: |
| code = self.code |
| else: |
| molecule_type = record.annotations.get("molecule_type") |
| if molecule_type is None: |
| code = "XX" |
| elif "DNA" in molecule_type: |
| code = "D1" |
| elif "RNA" in molecule_type: |
| code = "RL" |
| elif "protein" in molecule_type: |
| code = "P1" |
| else: |
| code = "XX" |
|
|
| if code not in _pir_mol_type: |
| raise TypeError( |
| "Sequence code must be one of " + _pir_mol_type.keys() + "." |
| ) |
| assert "\n" not in title |
| assert "\r" not in description |
|
|
| self.handle.write(f">{code};{title}\n{description}\n") |
|
|
| data = _get_seq_string(record) |
|
|
| assert "\n" not in data |
| assert "\r" not in data |
|
|
| if self.wrap: |
| line = "" |
| for i in range(0, len(data), self.wrap): |
| line += data[i : i + self.wrap] + "\n" |
| line = line[:-1] + "*\n" |
| self.handle.write(line) |
| else: |
| self.handle.write(data + "*\n") |
|
|
|
|
| if __name__ == "__main__": |
| from Bio._utils import run_doctest |
|
|
| run_doctest(verbose=0) |
|
|