Major component of the type IV fimbriae that plays an essential role in twitching motility, natural transformation, and protease secretion. The pili are polar flexible filaments of about 5.4 nanometers diameter and 2.5 micrometers average length; they consist of only a single polypeptide chain arranged in a helical configuration of five subunits per turn in the assembled pilus. Belongs to the N-Me-Phe pilin family. In PubMed:6653780 it is said that 50% of the peptides have N-methyl-Phe and 50% begin with Thr-9. N-terminal methylation produces preview during Edman degradation, which makes this appear to happen when the peptide is completely N-terminally methylated.