Fimbriae (also called pili), polar filaments radiating from the surface of the bacterium to a length of 0.5-1.5 micrometers and numbering 100-300 per cell, enable bacteria to colonize the epithelium of specific host organs. The major fimbrial subunit. Interacts with alpha-sialic acid-(2-3)-beta-Gal containing receptors. It belongs to the group of Mrh (Mannose-resistant hemagglutination) fimbrial proteins. Deletion leads to loss of fimbriation and a decrease of hemagglutination. This protein belongs to the group of SfA (S-fimbrial adhesins), which are associated with uropathogenic strains and with strains causing newborn meningitis. Belongs to the fimbrial protein family.