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| """Bio.AlignIO support for "xmfa" output from Mauve/ProgressiveMauve. |
| |
| You are expected to use this module via the Bio.AlignIO functions (or the |
| Bio.SeqIO functions if you want to work directly with the gapped sequences). |
| |
| For example, consider a progressiveMauve alignment file containing the following:: |
| |
| #FormatVersion Mauve1 |
| #Sequence1File a.fa |
| #Sequence1Entry 1 |
| #Sequence1Format FastA |
| #Sequence2File b.fa |
| #Sequence2Entry 2 |
| #Sequence2Format FastA |
| #Sequence3File c.fa |
| #Sequence3Entry 3 |
| #Sequence3Format FastA |
| #BackboneFile three.xmfa.bbcols |
| > 1:0-0 + a.fa |
| -------------------------------------------------------------------------------- |
| -------------------------------------------------------------------------------- |
| -------------------------------------------------------------------------------- |
| > 2:5417-5968 + b.fa |
| TTTAAACATCCCTCGGCCCGTCGCCCTTTTATAATAGCAGTACGTGAGAGGAGCGCCCTAAGCTTTGGGAAATTCAAGC- |
| -------------------------------------------------------------------------------- |
| CTGGAACGTACTTGCTGGTTTCGCTACTATTTCAAACAAGTTAGAGGCCGTTACCTCGGGCGAACGTATAAACCATTCTG |
| > 3:9476-10076 - c.fa |
| TTTAAACACCTTTTTGGATG--GCCCAGTTCGTTCAGTTGTG-GGGAGGAGATCGCCCCAAACGTATGGTGAGTCGGGCG |
| TTTCCTATAGCTATAGGACCAATCCACTTACCATACGCCCGGCGTCGCCCAGTCCGGTTCGGTACCCTCCATGACCCACG |
| ---------------------------------------------------------AAATGAGGGCCCAGGGTATGCTT |
| = |
| > 2:5969-6015 + b.fa |
| ----------------------- |
| GGGCGAACGTATAAACCATTCTG |
| > 3:9429-9476 - c.fa |
| TTCGGTACCCTCCATGACCCACG |
| AAATGAGGGCCCAGGGTATGCTT |
| |
| This is a multiple sequence alignment with multiple aligned sections, so you |
| would probably load this using the Bio.AlignIO.parse() function: |
| |
| >>> from Bio import AlignIO |
| >>> align = AlignIO.parse("Mauve/simple_short.xmfa", "mauve") |
| >>> alignments = list(align) |
| >>> for aln in alignments: |
| ... print(aln) |
| ... |
| Alignment with 3 rows and 240 columns |
| --------------------------------------------...--- a.fa |
| TTTAAACATCCCTCGGCCCGTCGCCCTTTTATAATAGCAGTACG...CTG b.fa/5416-5968 |
| TTTAAACACCTTTTTGGATG--GCCCAGTTCGTTCAGTTGTG-G...CTT c.fa/9475-10076 |
| Alignment with 2 rows and 46 columns |
| -----------------------GGGCGAACGTATAAACCATTCTG b.fa/5968-6015 |
| TTCGGTACCCTCCATGACCCACGAAATGAGGGCCCAGGGTATGCTT c.fa/9428-9476 |
| |
| Additional information is extracted from the XMFA file and available through |
| the annotation attribute of each record:: |
| |
| >>> for record in alignments[0]: |
| ... print(record.id, len(record)) |
| ... print(" start: %d, end: %d, strand: %d" %( |
| ... record.annotations['start'], record.annotations['end'], |
| ... record.annotations['strand'])) |
| ... |
| a.fa 240 |
| start: 0, end: 0, strand: 1 |
| b.fa/5416-5968 240 |
| start: 5416, end: 5968, strand: 1 |
| c.fa/9475-10076 240 |
| start: 9475, end: 10076, strand: -1 |
| |
| """ |
|
|
| import re |
|
|
| from Bio.Align import MultipleSeqAlignment |
| from Bio.Seq import Seq |
| from Bio.SeqRecord import SeqRecord |
|
|
| from .Interfaces import AlignmentIterator |
| from .Interfaces import SequentialAlignmentWriter |
|
|
| XMFA_HEADER_REGEX = re.compile( |
| r"> (?P<id>\d+):(?P<start>\d+)-(?P<end>\d+) (?P<strand>[+-]) (?P<name>.*)" |
| ) |
| XMFA_HEADER_REGEX_BIOPYTHON = re.compile( |
| r"> (?P<id>\d+):(?P<start>\d+)-(?P<end>\d+) (?P<strand>[+-]) (?P<name>[^#]*) # (?P<realname>.*)" |
| ) |
| ID_LINE_FMT = "> {seq_name}:{start}-{end} {strand} {filename} # {ugly_hack}" |
|
|
|
|
| def _identifier_split(identifier): |
| """Return (name, start, end) string tuple from an identifier (PRIVATE).""" |
| id, loc, strand = identifier.split(":") |
| start, end = map(int, loc.split("-")) |
| start -= 1 |
| return id, start, end, strand |
|
|
|
|
| class MauveWriter(SequentialAlignmentWriter): |
| """Mauve/XMFA alignment writer.""" |
|
|
| def __init__(self, *args, **kwargs): |
| """Initialize the class.""" |
| super().__init__(*args, **kwargs) |
| self._wrote_header = False |
| self._wrote_first = False |
|
|
| def write_alignment(self, alignment): |
| """Use this to write (another) single alignment to an open file. |
| |
| Note that sequences and their annotation are recorded |
| together (rather than having a block of annotation followed |
| by a block of aligned sequences). |
| """ |
| count = len(alignment) |
|
|
| self._length_of_sequences = alignment.get_alignment_length() |
|
|
| |
| |
|
|
| if count == 0: |
| raise ValueError("Must have at least one sequence") |
| if self._length_of_sequences == 0: |
| raise ValueError("Non-empty sequences are required") |
|
|
| if not self._wrote_header: |
| self._wrote_header = True |
| self.handle.write("#FormatVersion Mauve1\n") |
| |
| |
| |
| |
| for i in range(1, count + 1): |
| self.handle.write(f"#Sequence{i}Entry\t{i}\n") |
|
|
| for idx, record in enumerate(alignment): |
| self._write_record(record, record_idx=idx) |
| self.handle.write("=\n") |
|
|
| def _write_record(self, record, record_idx=0): |
| """Write a single SeqRecord to the file (PRIVATE).""" |
| if self._length_of_sequences != len(record.seq): |
| raise ValueError("Sequences must all be the same length") |
|
|
| seq_name = record.name |
| try: |
| seq_name = str(int(record.name)) |
| except ValueError: |
| seq_name = str(record_idx + 1) |
|
|
| |
| |
| if "start" in record.annotations and "end" in record.annotations: |
| suffix0 = f"/{record.annotations['start']}-{record.annotations['end']}" |
| suffix1 = f"/{record.annotations['start'] + 1}-{record.annotations['end']}" |
| if seq_name[-len(suffix0) :] == suffix0: |
| seq_name = seq_name[: -len(suffix0)] |
| if seq_name[-len(suffix1) :] == suffix1: |
| seq_name = seq_name[: -len(suffix1)] |
|
|
| if ( |
| "start" in record.annotations |
| and "end" in record.annotations |
| and "strand" in record.annotations |
| ): |
| id_line = ID_LINE_FMT.format( |
| seq_name=seq_name, |
| start=record.annotations["start"] + 1, |
| end=record.annotations["end"], |
| strand=("+" if record.annotations["strand"] == 1 else "-"), |
| filename=record.name + ".fa", |
| ugly_hack=record.id, |
| ) |
| lacking_annotations = False |
| else: |
| id_line = ID_LINE_FMT.format( |
| seq_name=seq_name, |
| start=0, |
| end=0, |
| strand="+", |
| filename=record.name + ".fa", |
| ugly_hack=record.id, |
| ) |
| lacking_annotations = True |
|
|
| |
| if (":0-0 " in id_line or ":1-0 " in id_line) and not lacking_annotations: |
| |
| if not self._wrote_first: |
| self._wrote_first = True |
| |
| |
| |
| id_line = ID_LINE_FMT.format( |
| seq_name=seq_name, |
| start=0, |
| end=0, |
| strand="+", |
| filename=record.name + ".fa", |
| ugly_hack=record.id, |
| ) |
| id_line = id_line.replace("\n", " ").replace("\r", " ") |
| self.handle.write(id_line + "\n\n") |
| |
| |
| else: |
| |
| |
| id_line = id_line.replace("\n", " ").replace("\r", " ") |
| self.handle.write(id_line + "\n") |
| for i in range(0, len(record.seq), 80): |
| self.handle.write(f"{record.seq[i : i + 80]}\n") |
|
|
|
|
| class MauveIterator(AlignmentIterator): |
| """Mauve xmfa alignment iterator.""" |
|
|
| _ids: list[str] = [] |
|
|
| def __next__(self): |
| """Parse the next alignment from the handle.""" |
| handle = self.handle |
| line = handle.readline() |
|
|
| if not line: |
| raise StopIteration |
|
|
| |
| while line and line.strip().startswith("#"): |
| line = handle.readline() |
|
|
| seqs = {} |
| seq_regions = {} |
| passed_end_alignment = False |
|
|
| latest_id = None |
| while True: |
| if not line: |
| break |
| line = line.strip() |
|
|
| if line.startswith("="): |
| |
| |
| break |
| elif line.startswith(">"): |
| m = XMFA_HEADER_REGEX_BIOPYTHON.match(line) |
| if not m: |
| m = XMFA_HEADER_REGEX.match(line) |
| if not m: |
| raise ValueError("Malformed header line: %s", line) |
|
|
| parsed_id = m.group("id") |
| parsed_data = {} |
| for key in ("start", "end", "id", "strand", "name", "realname"): |
| try: |
| value = m.group(key) |
| if key == "start": |
| value = int(value) |
| |
| if value > 0: |
| value -= 1 |
|
|
| if key == "end": |
| value = int(value) |
| parsed_data[key] = value |
| except IndexError: |
| |
| |
| pass |
| seq_regions[parsed_id] = parsed_data |
|
|
| if parsed_id not in self._ids: |
| self._ids.append(parsed_id) |
|
|
| seqs.setdefault(parsed_id, "") |
| latest_id = parsed_id |
| else: |
| assert not passed_end_alignment |
| if latest_id is None: |
| raise ValueError("Saw sequence before definition line") |
| seqs[latest_id] += line |
| line = handle.readline() |
|
|
| assert len(seqs) <= len(self._ids) |
|
|
| self.ids = self._ids |
| self.sequences = seqs |
|
|
| if self._ids and seqs: |
| alignment_length = max(map(len, list(seqs.values()))) |
| records = [] |
| for id in self._ids: |
| if id not in seqs or len(seqs[id]) == 0 or len(seqs[id]) == 0: |
| seq = "-" * alignment_length |
| else: |
| seq = seqs[id] |
|
|
| if alignment_length != len(seq): |
| raise ValueError( |
| "Sequences have different lengths, or repeated identifier" |
| ) |
|
|
| |
| |
| |
| if id not in seq_regions: |
| continue |
|
|
| if seq_regions[id]["start"] != 0 or seq_regions[id]["end"] != 0: |
| suffix = "/{start}-{end}".format(**seq_regions[id]) |
| if "realname" in seq_regions[id]: |
| corrected_id = seq_regions[id]["realname"] |
| else: |
| corrected_id = seq_regions[id]["name"] |
| if corrected_id.count(suffix) == 0: |
| corrected_id += suffix |
| else: |
| if "realname" in seq_regions[id]: |
| corrected_id = seq_regions[id]["realname"] |
| else: |
| corrected_id = seq_regions[id]["name"] |
|
|
| record = SeqRecord(Seq(seq), id=corrected_id, name=id) |
|
|
| record.annotations["start"] = seq_regions[id]["start"] |
| record.annotations["end"] = seq_regions[id]["end"] |
| record.annotations["strand"] = ( |
| 1 if seq_regions[id]["strand"] == "+" else -1 |
| ) |
|
|
| records.append(record) |
| return MultipleSeqAlignment(records) |
| else: |
| raise StopIteration |
|
|