DNA to Protein | translation incorrection

Question

I had no error. Always refresh cache and local memory.

Resources for Verifying Translations:

[NCBI Protein Translation Tool][1] (Validation)

[Text Compare][2] (Verification)

[Solution Inspiration][3]

300 DNA chars -> 100 protein chars.

---

# dna_sequence = above sequence

dna_codons = {
    'ATA':'I', 'ATC':'I', 'ATT':'I', 'ATG':'M',
    'ACA':'T', 'ACC':'T', 'ACG':'T', 'ACT':'T',
    'AAC':'N', 'AAT':'N', 'AAA':'K', 'AAG':'K',
    'AGC':'S', 'AGT':'S', 'AGA':'R', 'AGG':'R',                
    'CTA':'L', 'CTC':'L', 'CTG':'L', 'CTT':'L',
    'CCA':'P', 'CCC':'P', 'CCG':'P', 'CCT':'P',
    'CAC':'H', 'CAT':'H', 'CAA':'Q', 'CAG':'Q',
    'CGA':'R', 'CGC':'R', 'CGG':'R', 'CGT':'R',
    'GTA':'V', 'GTC':'V', 'GTG':'V', 'GTT':'V',
    'GCA':'A', 'GCC':'A', 'GCG':'A', 'GCT':'A',
    'GAC':'D', 'GAT':'D', 'GAA':'E', 'GAG':'E',
    'GGA':'G', 'GGC':'G', 'GGG':'G', 'GGT':'G',
    'TCA':'S', 'TCC':'S', 'TCG':'S', 'TCT':'S',
    'TTC':'F', 'TTT':'F', 'TTA':'L', 'TTG':'L',
    'TAC':'Y', 'TAT':'Y', 'TAA':'*', 'TAG':'*',
    'TGC':'C', 'TGT':'C', 'TGA':'*', 'TGG':'W',
} # replaced '_' for '*'

output_protein = ''
for i in range(0, len(dna_sequence), 3):
  codon = dna_sequence[i:i+3]
  output_protein += dna_codons.get(codon,'')
    
print(output_protein)

Example Problem & Solution: ps://www.geeksforgeeks.org/dna-protein-python-3/

Answer 1

I think the issue is with you mixing up variable names - your translation code appends to protein but you print output_protein which I assume is actually created somewhere else in your code(?). Also, you first edit the variable dna_sequence but iterate over dna which I assume is also defined elsewhere and maybe doesn't match dna_sequence.

After editing the variable names I can use your code to get the same translation as the NCBI tool.

dna_sequence = 'TTGTAGATCTGTTCTCTAAACGAACTTTAAAATCTGTGTGGCTGTCACTCGGCTGCATGCTTAGTGCACTCACGCAGTATAATTAATAACTAATTACTGTCGTTGACAGGACACGAGTAACTCGTCTATCTTCTGCAGGCGCTTACGGTTTCGTCCGTGTTGCAGCCGATCATCAGCACATCTAGGTTTTGTCCGGGTGTGACCGAAAGGTAAGATGGAGAGCCTTGTCCCTGGTTTCAACGAGAAAACACACGTCCAACTCAGTTTGCCTGTTTTACAGGTTCGCGACGTGCTCGTACG'
# dna_sequence = above sequence
if len(dna_sequence ) % 3 == 2: dna_sequence = dna_sequence [:-2]
if len(dna_sequence ) % 3 == 1: dna_sequence = dna_sequence [:-1]

#%% 
dna_codons = {
    'ATA':'I', 'ATC':'I', 'ATT':'I', 'ATG':'M',
    'ACA':'T', 'ACC':'T', 'ACG':'T', 'ACT':'T',
    'AAC':'N', 'AAT':'N', 'AAA':'K', 'AAG':'K',
    'AGC':'S', 'AGT':'S', 'AGA':'R', 'AGG':'R',                 
    'CTA':'L', 'CTC':'L', 'CTG':'L', 'CTT':'L',
    'CCA':'P', 'CCC':'P', 'CCG':'P', 'CCT':'P',
    'CAC':'H', 'CAT':'H', 'CAA':'Q', 'CAG':'Q',
    'CGA':'R', 'CGC':'R', 'CGG':'R', 'CGT':'R',
    'GTA':'V', 'GTC':'V', 'GTG':'V', 'GTT':'V',
    'GCA':'A', 'GCC':'A', 'GCG':'A', 'GCT':'A',
    'GAC':'D', 'GAT':'D', 'GAA':'E', 'GAG':'E',
    'GGA':'G', 'GGC':'G', 'GGG':'G', 'GGT':'G',
    'TCA':'S', 'TCC':'S', 'TCG':'S', 'TCT':'S',
    'TTC':'F', 'TTT':'F', 'TTA':'L', 'TTG':'L',
    'TAC':'Y', 'TAT':'Y', 'TAA':'*', 'TAG':'*',
    'TGC':'C', 'TGT':'C', 'TGA':'*', 'TGG':'W',
}

output_protein = ""
for i in range(0, len(dna_sequence), 3):
    codon = dna_sequence[i:i+3]
    output_protein += dna_codons.get(codon,'')

print(output_protein)

ncbi = 'L*ICSLNEL*NLCGCHSAACLVHSRSIINN*LLSLTGHE*LVYLLQALTVSSVLQPIISTSRFCPGVTER*DGEPCPWFQRENTRPTQFACFTGSRRART'
if ncbi == output_protein:
    print("Matches")