# How to translate amino acid sequences to Nucleotide sequences

I want to convert a list of fasta ( protein sequences) in a .text file into corresponding nucleotide sequences. A Google search gives me result of DNA to protein conversion but not vice versa. Also, I came across How do I find the nucleotide sequence of a protein using Biopython?, but this is what I am not looking for. Is there any possible way to do it using python.Moreover, I would like to solve it using python programming. I am sure there must be some way to do it rather than writing a code from scratch. Thanks!

Although there is not a unique nucleotide sequence that translates to a given protein, one can list all the possible DNA sequences that do translate to that protein.

An online tool that does just that is Backtranambig, from EMBOSS. It produces a DNA sequence representing all the nucleotide sequences matching the input protein, using IUPAC ambiguity codes.

DNA Chisel (written in Python) can reverse translate a protein sequence:

import dnachisel
from dnachisel.biotools import reverse_translate


You can't do this because there is redundancy in the genetic code and the same protein sequences can be encoded by different nucleotide sequences. There are 64 codons and ~20 amino acids, e.g. GCT, GCC, GCA and GCG all encode Alanine.