The outer sheath of the tail fiber is a bit stiff
Upon attachment to a bacterial cell, the sheath contracts, driving the tail tube through the host's cell envelope and injecting the viral genome into the cell. The subunits that form three of the six neighbouring helices (pink, A; blue, B; and green, C) within the sheath are shown as surface representations of (A) the extended and (B) the contracted sheath. Structurally these viruses have a prolate icosahedral capsid (the head) attached at one vertex to a long.
Read More