sub get_all_seqs{
    my $protein = shift;
    #print "protein = $protein\n";
    my @all_seqs;
    my %Deg_codons = get_degenerate();    
    my %SEQ = ();
    my @aas = split(//, $protein);
    my $aa = $aas[0];

    my @codons = @{$Deg_codons{$aa}};
    foreach my $codon(@codons){
        $SEQ{$codon}=1;
    }

    for(my $i=1; $i<@aas; $i++){
        my $aa = $aas[$i];
        @codons = @{$Deg_codons{$aa}};
        foreach my $seq(keys %SEQ){
            foreach my $codon(@codons){
                $SEQ{$seq.$codon}=1;
            }
            delete $SEQ{$seq};
        }    
    }

    @all_seqs = sort keys %SEQ;    
    
    return @all_seqs;
}