Convert molecular structure to protein sequence

Hi Folks,

Does anyone have a protocol that takes a set of molecules and converts them to the appropriate protein sequence, as given by the usual 1 or 3 letter codes for amino acids. Needless to say, this assumes/checks that the molecules read in are proteins.

I have tried using babel, as it reads and writes SMILES/SDF and FASTA formats. However it failed the simple test of converting a FASTA representation of a small peptide to smiles and back again to the FASTA format.

Any thoughts/suggestions on achiving this would be welcome.

Regards

Ian