Plays a central role in virus morphogenesis and assembly. Acts as a viroporin and self-assembles in host membranes forming pentameric protein-lipid pores that allow ion transport. Also plays a role in the induction of apoptosis. Homopentamer. Interacts with membrane protein M in the budding compartment of the host cell, which is located between endoplasmic reticulum and the Golgi complex. Interacts with Nucleoprotein. The cytoplasmic tail functions as a Golgi complex-targeting signal. Belongs to the alphacoronaviruses E protein family.