Removes the formyl group from the N-terminal Met of newly synthesized proteins. Has a preferred substrate specificity towards the photosystem II (PS II) D1 polypeptide. H2O + N-terminal N-formyl-L-methionyl-[peptide] = formate + N-terminal L-methionyl-[peptide] Binds 1 Fe(2+) ion. Inhibited by actinonin. Homodimer. Reported to be localized to chloroplast and mitochondria based on transient GFP expression in a heterologous system. Expressed in leaves and flowers. Albino. Belongs to the polypeptide deformylase family.