I have a list of peptide sequences, their respective protein names, their start and end co-ordinates in their protein sequences. Now I wanted to map them back to genomic source and get the genomic start and end co-ordinates(preferably exons) . I have tried several tools like proteogenomic mapping tools but no luck. Peptide atlas could able to provide the exonic co-ordinates but only one peptide is possible at a time, I have hundreds of peptides! Is there is any other way to do this! Please help me out! Thanks!