Plays a role in type II pseudopili formation by proteolytically removing the leader sequence from substrate proteins and subsequently monomethylating the alpha-amino group of the newly exposed N-terminal phenylalanine. Substrates include proteins required for biogenesis of the type II general secretory apparatus. Typically cleaves a -Gly-|-Phe- bond to release an N-terminal, basic peptide of 5-8 residues from type IV prepilin, and then N-methylates the new N-terminal amino group, the methyl donor being S-adenosyl-L-methionine. Belongs to the peptidase A24 family.