Using MEGAN for taxonomy assignment after metaproteome analysis

Hi everyone.
Could anyone direct me how I can obtain the taxonomy of a list of peptides. I basically want to infer the microbial species in my sample using the list of peptide obtained after a Comet search. Is it possible in MEGAN to link the obtain taxon, back to the peptide sequence or protein accession number linked to the peptide sequence?

You need to map the peptides to the nr database, but they might be too short for this.