Comet parameter: nucleotide_reading_frame
         
         - This parameter is used to search nucleotide sequence databases.
         
- It controls how the nucleotides are translated specifically
         which sets of reading frames are translated.
         
- Valid values are 0 through 9.
         
- Set this parameter to 0 for a protein sequence database.
         
- Set this parameter to 1 to search the 1st forward reading frame.
         
- Set this parameter to 2 to search the 2nd forward reading frame.
         
- Set this parameter to 3 to search the 3rd forward reading frame.
         
- Set this parameter to 4 to search the 1st reverse reading frame.
         
- Set this parameter to 5 to search the 2nd reverse reading frame.
         
- Set this parameter to 6 to search the 3rd reverse reading frame.
         
- Set this parameter to 7 to search all 3 forward reading frames.
         
- Set this parameter to 8 to search all 3 reverse reading frames.
         
- Set this parameter to 9 to search all 6 reading frames.
         
- The default value is "0" if this parameter is missing.
         
Example:
         
nucleotide_reading_frame = 0
         
nucleotide_reading_frame = 9