This family of protein represents gene product 14, a major component of the neck in T4-like viruses along with gene product 13. Gene product 14 is rich is beta-sheets. The formation of the neck to the head of the bacteriophage is crucial for the tail attachment [1].

1: The neck of bacteriophage T4 is a ring-like structure formed by a hetero-oligomer of gp13 and gp14. Akhter T, Zhao L, Kohda A, Mio K, Kanamaru S, Arisaka F; Biochim Biophys Acta. 2007;1774:1036-1043. PMID:17602902