Peptide Deformylase (def) is essential in Mycobacterium smegmatis, but the essentiality is compensated by inactivation of methionine formylation.

Peptide deformylase is essential in M. smegmatis, but the fact that inactivation of fmt renders the gene completely dispensable, and thus any inhibitor of def useless, casts doubt on the usefulness of PDF as a drug-target in mycobacteria.