def fill_gaps(ppr):
"""Look for reluctant motifs in suspiciously sized gaps"""
gaps = find_gaps(ppr, mingap=3 * 30, maxgap=3 * 40)
#check if there could be a motif at the start
if ppr.features[0].location.start > 3 * 30:
gaps.append(FeatureLocation(0, ppr.features[0].location.start, 1))
for g in gaps:
record = ppr[g.start - 15:g.end + 15]
record.seq = record.seq.translate()
#increase the reporting thresholds
search = HMMER.hmmsearch(hmm=models[3],
targets=record,
F1=0.5,
F2=0.5,
F3=0.5)
if search.matches:
motif = search.getFeatures(record)[0]
offset = g.start - 15
motif.location = FeatureLocation(offset + 3 * motif.location.start,
offset + 3 * motif.location.end,
strand=1)
ppr.features.append(motif)
ppr.features.sort(key=lambda p: p.location.start)
return ppr
def test_search_results(domE=10.0, verbose=False):
known = get_known()[0]
for k in known:
k.hit = 0
ara = SeqIO.parse(ARA_FILE, 'fasta').next()
search = HMMER.hmmsearch(hmm = extract.models[3], targets = ara, domE=domE)
found = search.getFeatures(ara)
for f in found:
p = int((f.location.start + f.location.end) / 2)
for k in known:
if p in k:
k.hit += 1
break
hits = [j.hit for j in known]
ret = {'matches': len(found),
'correct_matches': sum(hits),
'hit_pprs': sum([1 for i in hits if i > 0]),
'total_pprs': len(known),
'hits': hits,}
if verbose:
print "Found {} HMM domains, {} within known PPRs".format(
ret['matches'], ret['correct_matches'])
print "Hits in {} of {} PPR proteins".format(
ret['hit_pprs'], ret['total_pprs'])
print "Hits per PPR: min: {} / max: {} / avg: {}".format(
min(hits), max(hits), float(sum(hits)) / float(len(hits)))
return ret
def test_search_results(domE=10.0, verbose=False):
known = get_known()[0]
for k in known:
k.hit = 0
ara = SeqIO.parse(ARA_FILE, 'fasta').next()
search = HMMER.hmmsearch(hmm=extract.models[3], targets=ara, domE=domE)
found = search.getFeatures(ara)
for f in found:
p = int((f.location.start + f.location.end) / 2)
for k in known:
if p in k:
k.hit += 1
break
hits = [j.hit for j in known]
ret = {
'matches': len(found),
'correct_matches': sum(hits),
'hit_pprs': sum([1 for i in hits if i > 0]),
'total_pprs': len(known),
'hits': hits,
}
if verbose:
print "Found {} HMM domains, {} within known PPRs".format(
ret['matches'], ret['correct_matches'])
print "Hits in {} of {} PPR proteins".format(ret['hit_pprs'],
ret['total_pprs'])
print "Hits per PPR: min: {} / max: {} / avg: {}".format(
min(hits), max(hits),
float(sum(hits)) / float(len(hits)))
return ret
def classify(pprs, family_annot="ppr_family", tail_annot='ppr_tail'):
"""Annotate each ppr with it's family type, (P,PLS,E,E+,DYW)"""
ct = get_c_terminus(pprs)
(E, Ep, DYW) = utils.get_tail_models()
h = HMMER.hmmsearch([E,Ep,DYW], ct)
#annotate each tail
h.annotate(ct)
for ppr,tail in zip(pprs, ct):
fmt = ''
if tail.features:
f = sorted(tail.features, key=lambda(ft): int(ft.location.start))
fmt = ("-{.type}"*len(f)).format(*f)
if fmt[-3:] == 'DYW':
ppr.annotations[family_annot] = 'DYW'
elif fmt.find('E+') >= 0:
ppr.annotations[family_annot] = 'E+'
elif fmt.find('E') >= 0:
ppr.annotations[family_annot] = 'E'
else:
print "Unknown tail format \'{}\'".format(fmt)
ppr.annotations[family_annot] = '??'
else:
l = len(ppr.features[0])
for f in ppr.features:
if len(f) != l:
ppr.annotations[family_annot]='PLS'
continue
ppr.annotations[family_annot] = 'P'
ppr.annotations[tail_annot] = fmt
def locate_ppr(envelope):
"""Find and annotate the protein within"""
#find all the PPR motifs
search = HMMER.hmmsearch(hmm=models[3], targets=envelope)
motifs = search.getFeatures(envelope)
#A ppr must contain 2 or more PPR motifs
if len(motifs) < 2:
return None
#order the motifs
motifs.sort(key=lambda m: m.location.start)
known_start = True
known_stop = True
#find start codon
start = motifs[0].location.start
while start > 0 and str(envelope.seq[start:start + 3]).lower() != "atg":
start -= 3
if start < 0:
known_start = False
start = 0
#find stop codon
stop = motifs[-1].location.end
while stop < len(envelope) and (str(envelope.seq[stop:stop + 3]).lower()
not in ["tag", "tga", "taa"]):
stop += 3
if stop > len(envelope):
known_stop = False
stop = len(envelope)
#move the motifs
for m in motifs:
m.location = FeatureLocation(m.location.start - start,
m.location.end - start)
#get absolute start and end
if envelope.annotations['src_strand'] > 0:
src_from = envelope.annotations['src_from'] + start
src_to = envelope.annotations['src_from'] + stop
else:
src_from = envelope.annotations['src_to'] - stop
src_to = envelope.annotations['src_to'] - start
annotations = {
"src_from": src_from,
"src_to": src_to,
"src_strand": envelope.annotations['src_strand'],
}
if not known_stop:
annotations['no_stop'] = True
if not known_start:
annotations['no_start'] = True
#return a record
return SeqRecord(envelope.seq[start:stop],
features=motifs,
annotations=annotations)
def locate_ppr(envelope):
"""Find and annotate the protein within"""
#find all the PPR motifs
search = HMMER.hmmsearch(hmm = models[3], targets = envelope)
motifs = search.getFeatures(envelope)
#A ppr must contain 2 or more PPR motifs
if len(motifs) < 2:
return None
#order the motifs
motifs.sort(key=lambda m: m.location.start)
known_start = True
known_stop = True
#find start codon
start = motifs[0].location.start
while start > 0 and str(envelope.seq[start:start+3]).lower() != "atg":
start -= 3
if start < 0:
known_start = False
start = 0
#find stop codon
stop = motifs[-1].location.end
while stop < len(envelope) and (
str(envelope.seq[stop:stop+3]).lower() not in ["tag", "tga", "taa"]):
stop += 3
if stop > len(envelope):
known_stop = False
stop = len(envelope)
#move the motifs
for m in motifs:
m.location = FeatureLocation(m.location.start-start, m.location.end-start)
#get absolute start and end
if envelope.annotations['src_strand'] > 0:
src_from = envelope.annotations['src_from'] + start
src_to = envelope.annotations['src_from'] + stop
else:
src_from = envelope.annotations['src_to'] - stop
src_to = envelope.annotations['src_to'] - start
annotations = {
"src_from" : src_from,
"src_to" : src_to,
"src_strand": envelope.annotations['src_strand'],
}
if not known_stop:
annotations['no_stop'] = True
if not known_start:
annotations['no_start'] = True
#return a record
return SeqRecord(envelope.seq[start:stop],
features = motifs,
annotations = annotations)
def test_annotation(self):
#load the hmm
hmm = hmmfile.read('tests/data/valid.hmm')
s1 = SeqIO.read('tests/data/PPR10.gb', 'genbank')
s1.features = []
s2 = SeqIO.read('tests/data/PPR10.gb', 'genbank')
s2.features = []
s2.seq = s2.seq.reverse_complement()
h1 = HMMER.hmmsearch(hmm, s1)
h2 = HMMER.hmmsearch(hmm, s2)
h1.annotate(s1)
h2.annotate(s2)
for (f1, f2) in zip(s1.features, s2.features):
self.assertEqual(str(f1.extract(s1.seq)), str(f2.extract(s2.seq)))
def test_translation_search(self):
t = SeqIO.parse('tests/data/dna_target.fasta', 'fasta',
alphabet=Alphabet.generic_dna)
h = HMMER.hmmsearch('tests/data/valid.hmm', t)
self.assertEqual(len(h.matches), 17)
check_valid(self, h.matches)
#check that matches all have frame 1
for m in h.matches:
self.assertEqual(m.getFrame(), 1)
#test feature extraction
for m in h.matches:
f = m.asSeqFeature()
self.assertEqual(f.qualifiers['frame'], 1)
def simple_extract(target, localization=None, verbose=False):
"""Extract all the PPRs found in target"""
if not isinstance(target, SeqRecord):
raise TypeError(
"simple_extract requires a Bio.SeqRecord, not {}".format(
type(target)))
if verbose:
print "Searching..."
#find all easy-to-locate PPR motifs
search = HMMER.hmmsearch(hmm=models[3], targets=target)
#get features for each motif
motifs = search.getFeatures(target)
if verbose:
print "Got {} motifs, grouping...".format(len(motifs))
#group features by frame and locatiion
groups = group_motifs(motifs, max_gap=1500)
if verbose:
print "Got {} groups, extracting envelopes...".format(len(groups))
pprs = []
dbg_env = []
while groups:
if verbose:
print "Got {} groups, extracting envelopes...".format(len(groups))
#extract the sequence envelope around each group
envelopes = [
get_envelope(group, target, margin=1000) for group in groups
]
dbg_env += envelopes
if verbose:
print "Got {} envelopes, locating PPRs...".format(len(envelopes))
#locate the PPR within each envelope
for envelope in envelopes:
ppr = locate_ppr(envelope)
if ppr:
pprs.append(ppr)
#look for overlapping pprs
groups = remove_overlaps(pprs)
ol = len(groups)
if verbose:
print "{} conflicts".format(ol)
groups += remove_overgrown(pprs, 500)
if verbose:
print "{} overgrown PPRs".format(len(groups) - ol)
pprs = [add_source(p, target) for p in pprs]
if verbose:
print "Got {} PPRs, cleaning...".format(len(pprs))
#clean the gaps between features
pprs = [clean_ends(fill_gaps(ppr)) for ppr in pprs]
#annotate the tail region and classify each PPR
classify.classify(pprs)
#predict each PPR's target
targetp.targetp(pprs, annotation='localization')
#filter the desired location
if localization:
pprs = [
p for p in pprs if p.annotations['localization'] == localization
]
#return a list of nicely presented PPRs
return pprs
def test_search(self):
t = SeqIO.parse('tests/data/matchtarget.fasta', 'fasta',
alphabet=Alphabet.generic_protein)
h = HMMER.hmmsearch('tests/data/valid.hmm', t)
self.assertEqual(len(h.matches), 17)
check_valid(self, h.matches)
def setUp(self): #build a fake search self.hs = HMMER.hmmsearch() self.hs.hmms = [self.hmm,] self.hs.targets = [self.target,]
def simple_extract(target, localization = None, verbose=False):
"""Extract all the PPRs found in target"""
if not isinstance(target, SeqRecord):
raise TypeError("simple_extract requires a Bio.SeqRecord, not {}".format(
type(target)))
if verbose:
print "Searching..."
#find all easy-to-locate PPR motifs
search = HMMER.hmmsearch(hmm = models[3], targets = target)
#get features for each motif
motifs = search.getFeatures(target)
if verbose:
print "Got {} motifs, grouping...".format(len(motifs))
#group features by frame and locatiion
groups = group_motifs(motifs, max_gap=1500)
if verbose:
print "Got {} groups, extracting envelopes...".format(len(groups))
pprs = []
dbg_env = []
while groups:
if verbose:
print "Got {} groups, extracting envelopes...".format(len(groups))
#extract the sequence envelope around each group
envelopes = [get_envelope(group, target, margin=1000) for group in groups]
dbg_env += envelopes
if verbose:
print "Got {} envelopes, locating PPRs...".format(len(envelopes))
#locate the PPR within each envelope
for envelope in envelopes:
ppr = locate_ppr(envelope)
if ppr:
pprs.append(ppr)
#look for overlapping pprs
groups = remove_overlaps(pprs)
ol = len(groups)
if verbose:
print "{} conflicts".format(ol)
groups += remove_overgrown(pprs, 500)
if verbose:
print "{} overgrown PPRs".format(len(groups) - ol)
pprs = [add_source(p, target) for p in pprs]
if verbose:
print "Got {} PPRs, cleaning...".format(len(pprs))
#clean the gaps between features
pprs = [clean_ends(fill_gaps(ppr)) for ppr in pprs]
#annotate the tail region and classify each PPR
classify.classify(pprs)
#predict each PPR's target
targetp.targetp(pprs, annotation='localization')
#filter the desired location
if localization:
pprs = [p for p in pprs if p.annotations['localization'] == localization]
#return a list of nicely presented PPRs
return pprs
def fill_gaps(ppr): """Look for reluctant motifs in suspiciously sized gaps""" gaps = find_gaps(ppr, mingap=3*30, maxgap=3*40) #check if there could be a motif at the start if ppr.features[0].location.start > 3*30: gaps.append(FeatureLocation(0, ppr.features[0].location.start, 1)) for g in gaps: record = ppr[g.start-15:g.end+15] record.seq = record.seq.translate() #increase the reporting thresholds search = HMMER.hmmsearch(hmm = models[3], targets = record, F1=0.5,F2=0.5,F3=0.5) if search.matches: motif = search.getFeatures(record)[0] offset = g.start-15 motif.location = FeatureLocation( offset + 3*motif.location.start, offset + 3*motif.location.end, strand = 1) ppr.features.append(motif) ppr.features.sort(key=lambda p: p.location.start) return ppr
