Forms the central cylindrical hub of the baseplate and plays an important role in baseplate and tail assembly (Probable). Core component of the initiator complex that triggers the tail tube polymerization during tail assembly (Probable). Forms a conduit that probably functions as an extension of the tail tube allowing viral DNA release during ejection. Might facilitate the interaction of the virus with the host cell surface through electrostatic interactions during virus entry into host cell. Heterotrimer of one uncleaved (42 kDa) and two cleaved (40 kDa) forms. Forms a hub-like structure with an inner diameter of 25 Angstroms through which DNA can presumably pass during infection. Part of a complex composed of three DNA circularization protein N, three baseplate hub protein gp44 and three sub-complex wedge (made of two copies of each baseplate protein gp46, gp47 and gp48) that forms the baseplate (PubMed:27555589). Baseplate protein. Expressed in the late phase of the viral replicative cycle. Expression of late genes is activated by the viral late transcription activator C. C-terminal region forms a flexible domain. Cleavage of the C-terminus gives rise to a shorter 40 kDa form. No tail is synthesized.