Major repeating bundle-forming pilus (BFP) subunit. Is required for EPEC localized adherence. 10 to 100 laterally aligned filaments or bundle-forming pili coalesce into rope-like bundles. These form linkages between the bacteria within the enteropathogenic E.coli (EPEC) microcolonies that are attached to epithelial cells. Belongs to the N-Me-Phe pilin family. The modified residue is misidentified as methionine.