Peptide deformylase (PDF) is a metalloenzyme that removes the N-terminal formyl groups from newly synthesized proteins. It is essential for bacterial survival, and is therefore-considered as a potential target for antimicrobial chemotherapy. However, some bacteria including medically relevant pathogens possess two or more def-like genes. Here we have examined two PDFs from Bacillus cereus. The two share only 32% sequence identity and the crystal structures show overall similarity with PDF2 having a longer C-terminus. However, there are differences at the two active sites, and these differences appear to contribute to the activity difference seen between the two. BcPDF2 is found as a dimer in the crystal form with two additional actinonin bound at that interface.