Class: Bio::Sequence::NA

Inherits:
String show all
Includes:
Common
Defined in:
lib/bio/sequence/na.rb,
lib/bio/sequence/compat.rb,
lib/bio/shell/plugin/midi.rb

Overview

-- TODO

- add "Ohno" style
- add a accessor to drum pattern
- add a new feature to select music style (pop, trans, ryukyu, ...)
- what is the base?

++

Direct Known Subclasses

RestrictionEnzyme::SingleStrand

Defined Under Namespace

Classes: MidiTrack

Class Method Summary (collapse)

Instance Method Summary (collapse)

Methods included from Common

#+, #<<, #composition, #concat, #normalize!, #randomize, #seq, #splice, #subseq, #to_fasta, #to_s, #total, #window_search

Methods inherited from String

#fill, #fold, #skip, #step, #to_aaseq, #to_naseq

Constructor Details

- (NA) initialize(str)

Generate an nucleic acid sequence object from a string.

s = Bio::Sequence::NA.new("aagcttggaccgttgaagt")

or maybe (if you have an nucleic acid sequence in a file)

s = Bio::Sequence:NA.new(File.open('dna.txt').read)

Nucleic Acid sequences are always all lowercase in bioruby

s = Bio::Sequence::NA.new("AAGcTtGG")
puts s                                  #=> "aagcttgg"

Whitespace is stripped from the sequence

seq = Bio::Sequence::NA.new("atg\nggg\ttt\r  gc")
puts s                                  #=> "atggggttgc"

Arguments:

  • (required) str: String

Returns

Bio::Sequence::NA object



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# File 'lib/bio/sequence/na.rb', line 77

def initialize(str)
  super
  self.downcase!
  self.tr!(" \t\n\r",'')
end

Class Method Details

+ (Object) randomize(*arg, &block)

Generate a new random sequence with the given frequency of bases. The sequence length is determined by their cumulative sum. (See also Bio::Sequence::Common#randomize which creates a new randomized sequence object using the base composition of an existing sequence instance).

counts = {'a'=>1,'c'=>2,'g'=>3,'t'=>4}
puts Bio::Sequence::NA.randomize(counts)  #=> "ggcttgttac" (for example)

You may also feed the output of randomize into a block

actual_counts = {'a'=>0, 'c'=>0, 'g'=>0, 't'=>0}
Bio::Sequence::NA.randomize(counts) {|x| actual_counts[x] += 1}
actual_counts                     #=> {"a"=>1, "c"=>2, "g"=>3, "t"=>4}

Arguments:

  • (optional) hash: Hash object

Returns

Bio::Sequence::NA object



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# File 'lib/bio/sequence/compat.rb', line 87

def self.randomize(*arg, &block)
  self.new('').randomize(*arg, &block)
end

Instance Method Details

- (Object) at_content

Calculate the ratio of AT / ATGC bases. U is regarded as T.

s = Bio::Sequence::NA.new('atggcgtga')
puts s.at_content                       #=> 0.444444444444444

Returns

Float



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# File 'lib/bio/sequence/na.rb', line 319

def at_content
  count = self.composition
  at = count['a'] + count['t'] + count['u']
  gc = count['g'] + count['c']
  return 0.0 if at + gc == 0
  return at.quo(at + gc)
end

- (Object) at_skew

Calculate the ratio of (A - T) / (A + T) bases. U is regarded as T.

s = Bio::Sequence::NA.new('atgttgttgttc')
puts s.at_skew                          #=> -0.75

Returns

Float



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# File 'lib/bio/sequence/na.rb', line 347

def at_skew
  count = self.composition
  a = count['a']
  t = count['t'] + count['u']
  return 0.0 if a + t == 0
  return (a - t).quo(a + t)
end

- (Object) codon_usage

Returns counts of each codon in the sequence in a hash.

s = Bio::Sequence::NA.new('atggcgtga')
puts s.codon_usage                #=> {"gcg"=>1, "tga"=>1, "atg"=>1}

This method does not validate codons! Any three letter group is a 'codon'. So,

s = Bio::Sequence::NA.new('atggNNtga')
puts s.codon_usage                #=> {"tga"=>1, "gnn"=>1, "atg"=>1}

seq = Bio::Sequence::NA.new('atgg--tga')
puts s.codon_usage                #=> {"tga"=>1, "g--"=>1, "atg"=>1}

Also, there is no option to work in any frame other than the first.

Returns

Hash object



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# File 'lib/bio/sequence/na.rb', line 275

def codon_usage
  hash = Hash.new(0)
  self.window_search(3, 3) do |codon|
    hash[codon] += 1
  end
  return hash
end

- (Object) cut_with_enzyme(*args) Also known as: cut_with_enzymes

Example:

seq = Bio::Sequence::NA.new('gaattc')
cuts = seq.cut_with_enzyme('EcoRI')

or

seq = Bio::Sequence::NA.new('gaattc')
cuts = seq.cut_with_enzyme('g^aattc')

See Bio::RestrictionEnzyme::Analysis.cut



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# File 'lib/bio/sequence/na.rb', line 481

def cut_with_enzyme(*args)
  Bio::RestrictionEnzyme::Analysis.cut(self, *args)
end

- (Object) dna

Returns a new sequence object with any 'u' bases changed to 't'. The original sequence is not modified.

s = Bio::Sequence::NA.new('augc')
puts s.dna                              #=> 'atgc'
puts s                                  #=> 'augc'

Returns

new Bio::Sequence::NA object



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# File 'lib/bio/sequence/na.rb', line 425

def dna
  self.tr('u', 't')
end

- (Object) dna!

Changes any 'u' bases in the original sequence to 't'. The original sequence is modified.

s = Bio::Sequence::NA.new('augc')
puts s.dna!                             #=> 'atgc'
puts s                                  #=> 'atgc'

Returns

current Bio::Sequence::NA object (modified)



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# File 'lib/bio/sequence/na.rb', line 437

def dna!
  self.tr!('u', 't')
end

- (Object) forward_complement

Returns a new complementary sequence object (without reversing). The original sequence object is not modified.

s = Bio::Sequence::NA.new('atgc')
puts s.forward_complement               #=> 'tacg'
puts s                                  #=> 'atgc'

Returns

new Bio::Sequence::NA object



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# File 'lib/bio/sequence/na.rb', line 102

def forward_complement
  s = self.class.new(self)
  s.forward_complement!
  s
end

- (Object) forward_complement!

Converts the current sequence into its complement (without reversing). The original sequence object is modified.

seq = Bio::Sequence::NA.new('atgc')
puts s.forward_complement!              #=> 'tacg'
puts s                                  #=> 'tacg'

Returns

current Bio::Sequence::NA object (modified)



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# File 'lib/bio/sequence/na.rb', line 116

def forward_complement!
  if self.rna?
    self.tr!('augcrymkdhvbswn', 'uacgyrkmhdbvswn')
  else
    self.tr!('atgcrymkdhvbswn', 'tacgyrkmhdbvswn')
  end
  self
end

- (Object) gc_content

Calculate the ratio of GC / ATGC bases. U is regarded as T.

s = Bio::Sequence::NA.new('atggcgtga')
puts s.gc_content                       #=> 0.555555555555556

Returns

Float



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# File 'lib/bio/sequence/na.rb', line 305

def gc_content
  count = self.composition
  at = count['a'] + count['t'] + count['u']
  gc = count['g'] + count['c']
  return 0.0 if at + gc == 0
  return gc.quo(at + gc)
end

- (Object) gc_percent

Calculate the ratio of GC / ATGC bases as a percentage rounded to the nearest whole number. U is regarded as T.

s = Bio::Sequence::NA.new('atggcgtga')
puts s.gc_percent                       #=> 55

Returns

Fixnum



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# File 'lib/bio/sequence/na.rb', line 290

def gc_percent
  count = self.composition
  at = count['a'] + count['t'] + count['u']
  gc = count['g'] + count['c']
  return 0 if at + gc == 0
  gc = 100 * gc / (at + gc)
  return gc
end

- (Object) gc_skew

Calculate the ratio of (G - C) / (G + C) bases.

s = Bio::Sequence::NA.new('atggcgtga')
puts s.gc_skew                          #=> 0.6

Returns

Float



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# File 'lib/bio/sequence/na.rb', line 333

def gc_skew
  count = self.composition
  g = count['g']
  c = count['c']
  return 0.0 if g + c == 0
  return (g - c).quo(g + c)
end

- (Object) illegal_bases

Returns an alphabetically sorted array of any non-standard bases (other than 'atgcu').

s = Bio::Sequence::NA.new('atgStgQccR')
puts s.illegal_bases                    #=> ["q", "r", "s"]

Returns

Array object



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# File 'lib/bio/sequence/na.rb', line 362

def illegal_bases
  self.scan(/[^atgcu]/).sort.uniq
end

- (Object) molecular_weight

Estimate molecular weight (using the values from BioPerl's SeqStats.pm module).

s = Bio::Sequence::NA.new('atggcgtga')
puts s.molecular_weight                 #=> 2841.00708

RNA and DNA do not have the same molecular weights,

s = Bio::Sequence::NA.new('auggcguga')
puts s.molecular_weight                 #=> 2956.94708

Returns

Float object



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# File 'lib/bio/sequence/na.rb', line 378

def molecular_weight
  if self.rna?
    Bio::NucleicAcid.weight(self, true)
  else
    Bio::NucleicAcid.weight(self)
  end
end

- (Object) names

Generate the list of the names of each nucleotide along with the sequence (full name). Names used in bioruby are found in the Bio::AminoAcid::NAMES hash.

s = Bio::Sequence::NA.new('atg')
puts s.names                    #=> ["Adenine", "Thymine", "Guanine"]

Returns

Array object



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# File 'lib/bio/sequence/na.rb', line 409

def names
  array = []
  self.each_byte do |x|
    array.push(Bio::NucleicAcid.names[x.chr.upcase])
  end
  return array
end

- (Object) pikachu

:nodoc:



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# File 'lib/bio/sequence/compat.rb', line 91

def pikachu #:nodoc:
  self.dna.tr("atgc", "pika") # joke, of course :-)
end

- (Object) reverse_complement Also known as: complement

Returns a new sequence object with the reverse complement sequence to the original. The original sequence is not modified.

s = Bio::Sequence::NA.new('atgc')
puts s.reverse_complement               #=> 'gcat'
puts s                                  #=> 'atgc'

Returns

new Bio::Sequence::NA object



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# File 'lib/bio/sequence/na.rb', line 133

def reverse_complement
  s = self.class.new(self)
  s.reverse_complement!
  s
end

- (Object) reverse_complement! Also known as: complement!

Converts the original sequence into its reverse complement. The original sequence is modified.

s = Bio::Sequence::NA.new('atgc')
puts s.reverse_complement               #=> 'gcat'
puts s                                  #=> 'gcat'

Returns

current Bio::Sequence::NA object (modified)



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# File 'lib/bio/sequence/na.rb', line 147

def reverse_complement!
  self.reverse!
  self.forward_complement!
end

- (Object) rna

Returns a new sequence object with any 't' bases changed to 'u'. The original sequence is not modified.

s = Bio::Sequence::NA.new('atgc')
puts s.dna                              #=> 'augc'  
puts s                                  #=> 'atgc'

Returns

new Bio::Sequence::NA object



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# File 'lib/bio/sequence/na.rb', line 449

def rna
  self.tr('t', 'u')
end

- (Object) rna!

Changes any 't' bases in the original sequence to 'u'. The original sequence is modified.

s = Bio::Sequence::NA.new('atgc')
puts s.dna!                             #=> 'augc'
puts s                                  #=> 'augc'

Returns

current Bio::Sequence::NA object (modified)



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# File 'lib/bio/sequence/na.rb', line 461

def rna!
  self.tr!('t', 'u')
end

- (Object) splicing(position)

Alias of Bio::Sequence::Common splice method, documented there.



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# File 'lib/bio/sequence/na.rb', line 84

def splicing(position) #:nodoc:
  mRNA = super
  if mRNA.rna?
    mRNA.tr!('t', 'u')
  else
    mRNA.tr!('u', 't')
  end
  mRNA
end

- (Object) to_midi(style = {}, drum = true)

style:

Hash of :tempo, :scale, :tones

scale:

C  C# D  D# E  F  F# G  G# A  A#  B
0  1  2  3  4  5  6  7  8  9  10  11

tones:

Hash of :prog, :base, :range -- tone, vol? or len?, octaves

drum:

true (with rhythm part), false (without rhythm part)


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# File 'lib/bio/shell/plugin/midi.rb', line 351

def to_midi(style = {}, drum = true)
  default = MidiTrack::Styles["Ichinose"]
  if style.is_a?(String)
    style = MidiTrack::Styles[style] || default
  end
  tempo = style[:tempo] || default[:tempo]
  scale = style[:scale] || default[:scale]
  tones = style[:tones] || default[:tones]

  track = []

  tones.each_with_index do |tone, i|
    ch = i
    ch += 1 if i >= 9         # skip rythm track
    track.push MidiTrack.new(ch, tone[:prog], tone[:base], tone[:range], scale)
  end

  if drum
    rhythm = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
    track.push(MidiTrack.new(9, 0, 35, 2, rhythm))
  end

  cur = 0
  window_search(4) do |s|
    track[cur % track.length].push(s)
    cur += 1
  end

  track.each do |t|
    t.push_silent(12)
  end

  ans = track[0].header(track.length, tempo)
  track.each do |t|
    ans += t.encode
  end
  return ans
end

- (Object) to_re

Create a ruby regular expression instance (Regexp)

s = Bio::Sequence::NA.new('atggcgtga')
puts s.to_re                            #=> /atggcgtga/

Returns

Regexp object



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# File 'lib/bio/sequence/na.rb', line 393

def to_re
  if self.rna?
    Bio::NucleicAcid.to_re(self.dna, true)
  else
    Bio::NucleicAcid.to_re(self)
  end
end

- (Object) translate(frame = 1, table = 1, unknown = 'X')

Translate into an amino acid sequence.

s = Bio::Sequence::NA.new('atggcgtga')
puts s.translate                        #=> "MA*"

By default, translate starts in reading frame position 1, but you can start in either 2 or 3 as well,

puts s.translate(2)                     #=> "WR"
puts s.translate(3)                     #=> "GV"

You may also translate the reverse complement in one step by using frame values of -1, -2, and -3 (or 4, 5, and 6)

puts s.translate(-1)                    #=> "SRH"
puts s.translate(4)                     #=> "SRH"
puts s.reverse_complement.translate(1)  #=> "SRH"

The default codon table in the translate function is the Standard Eukaryotic codon table. The translate function takes either a number or a Bio::CodonTable object for its table argument. The available tables are (NCBI):

1. "Standard (Eukaryote)"
2. "Vertebrate Mitochondrial"
3. "Yeast Mitochondorial"
4. "Mold, Protozoan, Coelenterate Mitochondrial and Mycoplasma/Spiroplasma"
5. "Invertebrate Mitochondrial"
6. "Ciliate Macronuclear and Dasycladacean"
9. "Echinoderm Mitochondrial"
10. "Euplotid Nuclear"
11. "Bacteria"
12. "Alternative Yeast Nuclear"
13. "Ascidian Mitochondrial"
14. "Flatworm Mitochondrial"
15. "Blepharisma Macronuclear"
16. "Chlorophycean Mitochondrial"
21. "Trematode Mitochondrial"
22. "Scenedesmus obliquus mitochondrial"
23. "Thraustochytrium Mitochondrial"

If you are using anything other than the default table, you must specify frame in the translate method call,

puts s.translate                #=> "MA*"  (using defaults)
puts s.translate(1,1)           #=> "MA*"  (same as above, but explicit)
puts s.translate(1,2)           #=> "MAW"  (different codon table)

and using a Bio::CodonTable instance in the translate method call,

mt_table = Bio::CodonTable[2]
puts s.translate(1, mt_table)           #=> "MAW"

By default, any invalid or unknown codons (as could happen if the sequence contains ambiguities) will be represented by 'X' in the translated sequence. You may change this to any character of your choice.

s = Bio::Sequence::NA.new('atgcNNtga')
puts s.translate                        #=> "MX*"
puts s.translate(1,1,'9')               #=> "M9*"

The translate method considers gaps to be unknown characters and treats them as such (i.e. does not collapse sequences prior to translation), so

s = Bio::Sequence::NA.new('atgc--tga')
puts s.translate                        #=> "MX*"

Arguments:

  • (optional) frame: one of 1,2,3,4,5,6,-1,-2,-3 (default 1)

  • (optional) table: Fixnum in range 1,23 or Bio::CodonTable object (default 1)

  • (optional) unknown: Character (default 'X')

Returns

Bio::Sequence::AA object



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# File 'lib/bio/sequence/na.rb', line 234

def translate(frame = 1, table = 1, unknown = 'X')
  if table.is_a?(Bio::CodonTable)
    ct = table
  else
    ct = Bio::CodonTable[table]
  end
  naseq = self.dna
  case frame
  when 1, 2, 3
    from = frame - 1
  when 4, 5, 6
    from = frame - 4
    naseq.complement!
  when -1, -2, -3
    from = -1 - frame
    naseq.complement!
  else
    from = 0
  end
  nalen = naseq.length - from
  nalen -= nalen % 3
  aaseq = naseq[from, nalen].gsub(/.{3}/) {|codon| ct[codon] or unknown}
  return Bio::Sequence::AA.new(aaseq)
end