disulfidebond has asked for the wisdom of the Perl Monks concerning the following question:
Hello, this is my first time on Perl Monks. I'm a grad student practicing Bioinformatics for my dissertation. I found out about Rosalind beta bioinformatics problems (http://rosalind.info, no affiliation posted for interested people only) and decided to give them a shot. My problem is I am trying to parse a given string $s1, and find substrings designated by specific beginning and ending sequences. My code compiles, runs, returns strings which appear to be correct, but is "wrong" according to the website. If anyone can help, my question is if anyone can see any bugs in the code, and especially if anyone can suggest ways to optimize my code, I would greatly appreciate it. Thanks!
#!/usr/bin/perl -w # use Data::Dumper; $s1 = 'AGCCATGTAGCTAACTCAGGTTACATGGGGATGACCCCGCGACTTGGATTAGAGTCTCTTTTG +GAATAAGCCTGAATGATCCGAGTAGCATCTCAG'; print "$s1\n"; # copy string $s1 to array @arr_ @arr_ = split ('', $s1); # must test for initial methionine # assign @arr_ array to string $arr_met to test $arr_met = join('', @arr_); $sub_met = substr($arr_met, 0, 3); if ($sub_met =~ m/ATG/) { # if match is TRUE, call &proteintrans to translate # else do nothing my $peptide = proteintrans($arr_met); print "\n$peptide\n"; } else { print "\nno initial match, moving along...\n"; } # for each iteration of loop # shift $j element off front of array to alter reading frame # assign array @arr_ to string $dna_string for processing # call &testformethionine subroutine print "@arr_\n"; $len = @arr_; for ($j = 0; $j < $len; $j++) { shift @arr_; $dna_string = join('', @arr_); # debugging step # print "\n$dna_string\n"; testformethionine($dna_string); } sub testformethionine { my ($dnastr) = @_; # create substring from first 3 amino acids my $sub1 = substr($dnastr, 0, 3); # print "$sub1\n"; # if matches ATG (Met) proceed through translation &proteintrans # else do nothing if ($sub1 =~ m/ATG/) { my $peptide = proteintrans($dnastr); print "$peptide\n"; } else { # debugging line of code # print "move along, polymerase\n"; } } sub proteintrans { my ($dna) = @_; my $protein = ''; # split amino acids into 3 with for loop and concatenate for(my $i = 0; $i < (length($dna) - 2) ; $i +=3) { $protein .= codons(substr($dna, $i, 3)); } # return $protein; # $len_ = length($protein); if ($protein =~ m/_/) { # if string $protein matches stop codon '_' # find match with index() # form a substring before stop codon with substr() # return new substring protein_ $index = index($protein, '_'); $protein_ = substr($protein, 0, $index); return $protein_; } else { # else return protein unmodified return $protein; } } sub codons { # use hash table to assign codons my($codon) = @_; $codon = uc $codon; my (%genetic_code) = ( 'TCA' => 'S', # Serine 'TCC' => 'S', # Serine 'TCG' => 'S', # Serine 'TCT' => 'S', # Serine 'TTC' => 'F', # Phenylalanine 'TTT' => 'F', # Phenylalanine 'TTA' => 'L', # Leucine 'TTG' => 'L', # Leucine 'TAC' => 'Y', # Tyrosine 'TAT' => 'Y', # Tyrosine 'TAA' => '_', # exit 'TAG' => '_', # exit 'TGC' => 'C', # Cysteine 'TGT' => 'C', # Cysteine 'TGA' => '_', # exit 'TGG' => 'W', # Tryptophan 'CTA' => 'L', # Leucine 'CTC' => 'L', # Leucine 'CTG' => 'L', # Leucine 'CTT' => 'L', # Leucine 'GTT' => 'V', # Valine 'GTC' => 'V', # Valine 'GTA' => 'V', # Valine 'GTG' => 'V', # Valine 'GCT' => 'A', # Alanine 'GCC' => 'A', # Alanine 'GCA' => 'A', # Alanine 'GCG' => 'A', # Alanine 'GAT' => 'D', # Aspartic Acid 'GAC' => 'D', # Aspartic Acid 'GAA' => 'E', # Glutamate 'GAG' => 'E', # Glutamate 'GGT' => 'G', # Glycine 'GGC' => 'G', # Glycine 'GGA' => 'G', # Glycine 'GGG' => 'G', # Glycine 'CCA' => 'P', # Phenylalanine 'CCC' => 'P', # Phenylalanine 'CCG' => 'P', # Phenylalanine 'CCT' => 'P', # Phenylalanine 'CAC' => 'H', # Histidine 'CAT' => 'H', # Histidine 'CAA' => 'Q', # Glutamine 'CAG' => 'Q', # Glutamine 'CGA' => 'R', # Arginine 'CGC' => 'R', # Arginine 'CGG' => 'R', # Arginine 'CGT' => 'R', # Arginine 'ATA' => 'I', # Isoleucine 'ATC' => 'I', # Isoleucine 'ATT' => 'I', # Isoleucine 'ATG' => 'M', # Methionine 'ACA' => 'T', # Threonine 'ACC' => 'T', # Threonine 'ACG' => 'T', # Threonine 'ACT' => 'T', # Threonine 'AAC' => 'N', # Asparagine 'AAT' => 'N', # Asparagine 'AAA' => 'K', # Lysine 'AAG' => 'K', # Lysine 'AGC' => 'S', # Serine 'AGT' => 'S', # Serine 'AGA' => 'R', # Arginine 'AGG' => 'R', # Arginine # hash table and subroutine from "Beginning Perl for Bioinformatics" # by James Tisdall. c2001 O'Reilly Press. ); if(exists $genetic_code{$codon}) { return $genetic_code{$codon}; } else { print STDERR "$codon not found\n"; exit; } }
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Re: Need help with code
by grondilu (Friar) on Oct 19, 2012 at 05:03 UTC | |
A critique (was Re: Need help with code)
by roboticus (Chancellor) on Oct 19, 2012 at 14:11 UTC | |
by disulfidebond (Novice) on Oct 21, 2012 at 00:31 UTC | |
by roboticus (Chancellor) on Oct 21, 2012 at 06:05 UTC | |
Re: Need help with code
by McA (Priest) on Oct 19, 2012 at 08:32 UTC |
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