Removes the formyl group from the N-terminal Met of newly synthesized proteins. H2O + N-terminal N-formyl-L-methionyl-[peptide] = formate + N-terminal L-methionyl-[peptide] Binds 1 Zn(2+) ion per subunit. Inhibited by actinonin. Homodimer. Reported to be localized to mitochondria, based on transient GFP expression in a heterologous system (PubMed:11060042), but also shown to be imported and correctly processed in isolated chloroplast (PubMed:11553738). Expressed in roots, leaves, flowers and siliques. No visible phenotype. Belongs to the polypeptide deformylase family. Truncated N-terminus. Truncated N-terminus.