Dec. 17, 2015, 11:32 a.m. by Robert Goldberg-Alberts
Six different reading frames (2 directions x 3 offsets) can generate six different translated peptides from a single strand of DNA** . Being able to reproduce from a 5'3' strand of DNA, the 3'5' strand, the corresponding transcribed RNAs and the six translated pepetides (amino acid sequences) shows that the student has a basic understanding of the transcription and translation process. (Reading, transcribing and translating the 3' 5' right to left direction is particularly important). This exercise also demonstrates the overlapping nature of the DNA code.
Successful completion also shows an understanding of the conventions for representing amino acids.
Source: Figure 4.3 page 187 (second edition) of BIOINFORMATICS ALGORITHMS An Active Learning Approach...
A strand of DNA contains nucleotides, that when properly transcribed to RNA allows translation to proteins illustrating the classic role of DNA in providing information for the proper sequencing of peptides.
DNA -----> RNA ------> Peptide.
Given: A DNA string
Two dictionary files which translate RNA codons to the single letter convention for amino acids and the three letter convention for amino acids or one dictionary file that translates RNA codons directly to the three letter convention for amino acids.
Return: The program should output the following:
**DNA 5'3': GTGAAACTTTTTCCTTGGTTTAATCAATAT RNA 5'3': GUGAAACUUUUUCCUUGGUUUAAUCAAUAU offset: 2 peptide: GluThrPheSerLeuValSTPSerIle offset: 1 peptide: STPAsnPhePheLeuGlyLeuIleAsn offset: 0 peptide: ValLysLeuPheProTrpPheAsnGlnTyr DNA 3'5': CACTTTGAAAAAGGAACCAAATTAGTTATA RNA 3'5': CACUUUGAAAAAGGAACCAAAUUAGUUAUA offset: 0 peptide: HisPheLysLysArgProLysIleLeuIle offset: -1 peptide: PheSerLysGlyGlnAsnLeuSTPTyr offset: -2 peptide: SerValLysGluLysThrSTPAspIle** >>>