Assembles together with p132 to form the three L-shaped long tail fibers and the collar structure at the junction between the tail tube and the conical tail tip (PubMed:24198424). The three L-shaped long tail fibers recognize the host lipopolysaccharides that serve as adhesion receptor for virus entry (PubMed:7045389). Each fiber consists of a thin proximal rod of about 30 nm connected by a hinge to a thicker distal part of about 47 nm (PubMed:24198424). Homotrimer (PubMed:24316831). Interacts with the O-antigens of host lipopolysaccharides (PubMed:7045389). Part of the tail long fibers. The cleaved C-terminus functions as an intramolecular chaperone and is removed by an autoproteolytic process after correct trimerization and folding.