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How can I retrieve nucleotide sequences from amino acid sequences?

Hello everyone,

Here is my situation. I have some nucleotide sequences from which amino acid sequences were predicted using Prodigal. Then an hmmsearch of a target amino acid seqs was performed on the predicted a.a. seqs, and it returned a list of hits that are below an E-value threshold. Now I'd like to get the nucleotide seqs of the hits from hmmsearch, is there any software that can achieve this?

Thank you very much!

nucleotide sequences protein

as said here before, without prior knowledge it is not possible to get the nucleotide sequence from a given protein sequence.

However, if the protein sequences you screened with the hmmsearch is against a DB of known proteins (eg. from the human genome) you can perhaps back-trace the nucleotide sequence based on the protein IDs.

Thank you for your answer Lieven, do you have any idea what tool should I use to back-trace the nucleotide sequences?

no tool required, I was thinking along the line of looking up the IDs in the DBs.

1 answer

There is no way to recover the exact nucleotide sequence from proteins due to genetic code degeneracy.

When you run prodigal, simply use both -a proteins.faa and -d genes.fna switches. That way you will have both protein and DNA sequences.

Thank you Mensur, this is great, I am gonna give it a try!

I also wonder if it's possible to match the protein hits returned from hmmsearch to the sequences in genes.fna?

Hello Mensur, so I just re-ran prodigal by including the -d option, the header sections are identical as that of the protein sequences created from the -a option. This way I will be able to match the protein seq with the DNA seq.

Thank you for your great solution, I appreciate it!

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